FNGINES 
 
 CONSTRUCTION, CARE AND OPERATION 
 
 WITH OyESTlONSAND ANSWERS 
 
 SWINGLE 
 
 
 UNIVERSITY OF CALIFORNIA. LIBRARY 
 
 ^ * ** 
 
 THIS BOOK IS NOT, 3^ BE TAKEN FROM 
 
 ROOM 
 
 
 WHEN BOftE WITH, RETURN AT ~QNCE TO ITS 
 PLACE ON THE SHELVES 
 
 s 
 
 r- 
 o 
 
 03 
 
LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA. 
 
 Class 
 
STEAM TURBINE 
 ENGINES 
 
 Their Construction, Care and Operation 
 
 The principles governing the Action of the Steam in the 
 
 various types of Steam Turbines are clearly set 
 
 forth in plain language, not too technical 
 
 for the man with an ordinary 
 
 education to understand. 
 
 Full Instructions Regarding Correct 
 Methods of Operating Steam Turbines, 
 Adjusting Clearances, etc., etc. 
 
 BY 
 
 CALVIN F. ^WINGLE 
 
 Author of "Twentieth Century Hand Book for Steam Engineers and 
 
 Electricians," "Modern Locomotive Engineering," 
 
 "Modern Steam Boilers" and "Catechism 
 
 for Engineers and Electricians." 
 
 OFTHC 
 
 UNIVERSITY 
 
 OF 
 
 CHICAGO 
 
 FREDERICK J. DRAKE & COMPANY 
 

 JCOPYRIGHT 1910 
 BY 
 
 FREDERICK J. DRAKE & Co. 
 
INTRODUCTION 
 
 The rapid increase within recent years, in the number of 
 installations of steam turbines for power purposes, renders 
 it absolutely necessary that the engineer who is in charge 
 of, or is confronted with a possibility of being placed in 
 charge of a steam turbine plant, should make himself 
 thoroughly acquainted with the principles controlling the 
 action of steam turbines; also the details connected with 
 their care, and successful operation. This knowledge he 
 can obtain by a close study of the following pages, in which 
 are set forth in plain, simple language the underlying prin- 
 ciples of the turbine, and its advantages as a prime mover. 
 The book also contains descriptions in detail of the several 
 different types of steam turbines that have, on account of 
 their merits come to be standard in this country. Each 
 type is clearly illustrated and explained. There is also a 
 plain and forcible discussion of methods used in the dis- 
 posal of the exhaust steam of steam turbines, much of which 
 will also apply to reciprocating engines, and this in itself 
 will prove to be of great benefit to the student engineer, 
 for the reason that in many steam plants conditions exist 
 which call for a complete working knowledge of both the 
 Turbine, and the Eeciprocating types of prime movers, due 
 to the fact that both types of engines are often being 
 operated by the same firm or corporation. In addition to 
 the foregoing matter, there is also a complete list of ques- 
 tions and answers pertaining to the principles of steam 
 turbines, and their operation and management, all of which 
 will be found to be of inestimable value to the student seek- 
 ing knowledge along this line. 
 
 217106 
 
OF THE 
 
 UNIVERSITY 
 
 OF 
 
 The Steam Turbine 
 
 Although the turbine principle of utilizing the heat 
 energy in steam and converting it into useful work has 
 been experimented upon for many years, it is only since 
 the inauguration of the twentieth century that steam tur- 
 bines have been brought to the front as efficient power 
 producers. 
 
 The piston of the reciprocating engine is driven back 
 and forth by the static expansive force of the steam, while 
 in the steam turbine not only the expansive force is made 
 to do work, but a still more important element is utilized, 
 viz., the kinetic energy, or heat energy latent in the steam, 
 and which manifests itself in the rapid vibratory motion of 
 the particles of steam expanding from a high, to a low 
 pressure, and this motion the steam turbine transforms 
 into work. 
 
 Notwithstanding the fact that much has been said and 
 written during the past four years regarding the steam 
 turbine, the machine is to-day a mystery to thousands of 
 engineers, not because they do not desire information upon 
 the subject, but because of a lack of opportunities for ob- 
 taining that information. The author therefore considers 
 that a space devoted to this subject would no doubt be of 
 benefit to his readers. 
 
 The steam turbine is simple and compact in design, hav- 
 ing few working parts as compared with the reciprocating 
 engine, and any engineer who is capable of operating and 
 caring for an engine of the latter type, can also run and 
 take care of a steam turbine. But, as in the case of the 
 
 7 
 
Steam Engineering 
 
 FIG. 235 
 FOUR WESTINGHOUSE-PABSONS STEAM TURBINES 
 
Principle of 9 
 
 reciprocating engine, the engineer in charge of a turbine 
 plant should be familiar with the interior construction of 
 the machines under his charge, and he should know what 
 to do, and what to avoid in order to keep them in continual 
 and efficient operation. 
 
 FIG. 236 / 
 
 The steam turbine in principle, and even in type is not 
 new, being in fact the first heat motor of which we have 
 any record in steam engineering. 
 
 One of the earliest descriptions of a device for convert- 
 ing the power of steam into work was recorded by Hero, 
 a learned writer who flourished in the city of Alexandria 
 
10 
 
 titeam Engineering 
 
 in Egypt, in the second century before Christ. Hero de- 
 scribes a machine called an Aeolipile or "Ball of Aeolus." 
 illustrated in Fig. 236. B is the boiler under which a 
 fire was made. G is a hollow metallic globe that revolved 
 on trunnions C and D, one of which terminated in a pivot 
 at E, while the other was hollow and conveyed the steam 
 generated in the boiler B to the interior of the globe or 
 ball, from which it escaped through the hollow bent tubes 
 H and I, and the reaction of the escaping steam caused the 
 
 FIG. 237 
 
 globe to revolve. This was the first steam turbine, and 
 it worked on the reaction principle. 
 
 Many centuries later, in the year A. D. 1629, Braiu-n, 
 an Italian, described an engine which marks a change in 
 the method of using the steam. Branca's engine consisted 
 of a boiler A, Fig. 237, from which the steam issued through 
 a straight pipe, and impinged upon the vanes of a hori- 
 zontal wheel carried upon a vertical shaft, causing it to 
 revolve. This device was the germ of the impulse tur- 
 
Principle of 11 
 
 bine, and these two principles, viz., reaction and impulse, 
 either one or the other, and sometimes a combination of 
 both, are the fundamental principles upon which the suc- 
 cessful steam turbines of the present age operate. 
 
 Steam expanding through a definite range of tempera- 
 ture and pressure exerts the same energy whether it issues 
 from a suitable orifice or expands against a receding piston. 
 
 Two transformations of energy take place in the steam 
 turbine; first, from thermal to kinetic energy; second, 
 from kinetic energy to useful work. The latter alone pre- 
 sents an analogy to the hydraulic turbine. 
 
 The radical difference between the two turbines lies in 
 the low density of steam as compared to water, and the 
 wide variation of its volume under varying temperatures 
 and pressures. 
 
 A cubic foot of steam under 100 Ibs. pressure, if allowed 
 to discharge into a vacuum of 28 inches, would attain a 
 theoretical velocity of 3,860 feet per second and would 
 exert 59,900 ft. Ibs. of energy. 
 
 A law of turbo-mechanics specifies that in order to ob- 
 tain the highest efficiency in the operation of turbines 
 (whether water or steam) the relation between bucket 
 speed and fluid speed, (steam in this case), should be as 
 follows : 
 
 For purely impulse wheels, bucket speed equals one-half 
 of jet speed. 
 
 For reaction wheels, bucket speed equals jet speed. 
 
 Assuming the velocity of the jet of steam issuing from 
 the nozzle to be 4.000 feet per second, this would mean 
 a peripheral speed of 2,000 feet per second for an im- 
 pulee wheel, and for a wheel 1 foot in diameter the speed 
 would be 38,100 R. P. M. But such a speed is beyond 
 
12 
 
 Steam Engineering 
 
 the limits of strength of material, and the speed of steam 
 turbines is accordingly kept within the bounds of safety, 
 and strength of material. 
 
 Form of Blade. The blades or buckets should be of 
 such form, and curvature as will permit the steam to ex- 
 pand to the desired final, or terminal pressure with the 
 smallest possible friction and eddy current losses. As to 
 directing the flow in the desired course, the direction of 
 
 FIG. 238 
 
 exit from the guide, and rotating wheel is of the greatest 
 importance. In order to get the desired angle, the last 
 part of the blade should be kept straight, at least to the 
 foot of the perpendicular dropped from A 1? or the length 
 A B in Fig. 238. From there on, the channel should lead 
 in easy curvature to the angle a v The construction ac- 
 cording to a in Fig. 238 would obviously be too sharp, and 
 would cause the steam stream to separate from the wall. 
 
Construction 13 
 
 The construction according to b would suffice, and the 
 wheel radius would depend, above all, upon how far we 
 wish to dimmish the shock at entrance. For the profile b 
 the angle a is taken as the slope of the blade back, from 
 which we obtain for the guiding blade surface the some- 
 what large angle a/. This would be more favorable with c, 
 and d, but the latter would obviously give a needlessly 
 long steam path. Besides, a pointing of the blade such 
 that a is half of a/, as is shown dotted at d, could be con- 
 sidered just as correct as the first mentioned. By drawing 
 the absolute steam path and finding the decrease of peri- 
 pheral speed, we get useful results concerning the regu- 
 larity of delivering work. 
 
 The proper length of the channel, or steam path can 
 only be determined by practical experience, and with a 
 given curvature the ratio of length to breadth can be con- 
 sidered fairly constant. 
 1* 
 
 Stuffing Boxes. The stuffing boxes are the most im- 
 portant and . delicate part of the steam turbine. As they 
 are" subjected to high temperature on account of their 
 proximity to the steam space, the problem of getting rid of 
 their own heat of friction becomes all the more difficult. 
 The advantage of the stuffing box used on reciprocating 
 engines, where the rod for part of the time is exposed to 
 the air, and cools at least its surface by radiation, cannot 
 be considered with the rotating shaft. Water-cooling may 
 be an effective means, but creates considerable loss by con- 
 densation in the surrounding steam spaces. 
 
 The majority of designers get around this difficulty by 
 avoiding contact between packing and shaft, and secure 
 tightness only by the least possible clearance. This is the 
 principle of the so-called "labyrinth stuffing box" that was 
 
1-1 tilcdiii Engineering 
 
 first generally used by Parsons. This is shown in Fig. 
 239, in which A is the shaft, B the stuffing hox. The rings 
 
 y x y 
 FIG. 239 
 LABARYNTH STUFFING BOX 
 
 on both parts form alternately a narrow space x, and a 
 large space y. The velocity of the steam flowing through 
 this narrow space is destroyed by eddy-currents in the 
 
 FIG. 240 
 
 FIG. 241 
 
 large space, so that for further velocity, a part of the drop 
 in pressure is utilized. With a large number of rings, 
 and with very small spaces x, the loss is greatly decreased. 
 
Construction 
 
 15 
 
 It also seems to have a favorable influence when the steam 
 in leaving this narrow space flows radially inwards, that is, 
 it helps to overcome its centrifugal force. 
 
 Fig. 240 shows the stuffing hox of a Schulz turbine. No 
 provision is here made for enlarged spaces, but the neces- 
 sary throttling is accomplished by the great length of the 
 labvrinth path. The designer hoped to limit his clearance 
 to 1 mm. (0.039 in.). The outer box is made in two parts. 
 
 FIG. 242 
 
 Fig. 241 shows a stuffing, box by the same designer, built 
 of rings, in which the inner rings are loose, but are made 
 with a neat fit. 
 
 The Rateau stuffing box is shown in Fig. 242. The 
 main part consists of the shaft, a, enclosed by a close fit- 
 ting box b, of suitable metal. The steam leaking through 
 this space flows into chamber c, where a constant pressure 
 of about 12 Ibs. absolute is maintained by a reducing valve. 
 From the valve the steam is led to a condenser. Chamber 
 c, is kept steam tight from the outside by two bronze rings 
 
16 Steam Engineering 
 
 d, d, each made in three parts, which are held against the 
 shaft with slight pressure by the spiral springs e. A pres- 
 sure in an axial direction is caused by springs f. The 
 chambers of all the stuffing boxes of the turbine are con- 
 nected together. Thus a portion of the steam that leaves 
 the high pressure chamber will be drawn into the low pres- 
 sure side. When running light, partial vacuum exists in 
 all the stuffing boxes, the reducing valve allowing live 
 
 FIG. 243 
 
 steam to enter, thus preventing air from being drawn in. 
 
 Steam is led in Figs. 240 and 241 through the ring 
 passages, and excludes thereby the air, so that the vacuum 
 does not suffer. 
 
 The construction of a turbine stuffing box as steam tight 
 as that of the steam engine is still an unsolved problem. 
 For this reason we might add the excellent stuffing box of 
 Schwabe, that is used in steam-engine work, shown in 
 Fig. 243. This consists of a large number of rings D 
 
Regulation 17 
 
 made in three parts, held together by a circumferential 
 spiral spring. These rings (for the steam engine) press 
 on one another, and should either not touch the shaft at 
 all, or with only the slightest pressure. With turbines, the 
 soft packing at the outer end will of course be omitted, 
 and the rings must be prevented from turning, and so con- 
 structed as to be tight against either pressure or vacuum. 
 The inside and outside ends of the box are provided with 
 means for oiling. 
 
 The Regulation of the Steam Turbine. The regulation 
 in the majority of different systems is acomplished by sim- 
 ple throttling, thus decreasing, at the very beginning, the 
 available work of the steam, and consequently the economy 
 of the turbine. The loss is measured by the product of the 
 increase of entropy and the absolute temperature of the 
 exhaust steam, which can easily be determined from the 
 entropy tables. 
 
 The ideal conditions would be to constantly work with a 
 full initial pressure, and to make all cross-sections of steam 
 passages suitable to the power required. Constructively, 
 this idea is most easily applicable to the single stage im- 
 pulse turbine, in which the nozzles are opened or closed one 
 after another by means of a regulator. 
 
 The following description of the construction, and prin- 
 ciples controlling the action of the leading types of steam 
 turbines manufactured in the United States is presented, 
 with the hope that it may prove to be not only interesting, 
 but instructive as well, to the student. 
 
 It may be said in general of the steam turbine, that it 
 has passed the experimental stage, and has come to the 
 front as an efficient power producer, having a bright 
 future before it. It has solved the problem of using super- 
 
18 Steam Engineering 
 
 heated steam, owing to the absence of all rubbing pnrts 
 exposed to the steam. This permits the use of steam of 
 high temperature, thus making it possible to realize the 
 advantages of economical operation. 
 
The Westinghouse-Parsons Steam 
 Turbine 
 
 The Westinghouse-Parsons Steam Turbine operates on 
 both impulse and reaction principles, and by a system of 
 compounding, which will be explained later on, the peri- 
 pheral velocity of the machine has been so reduced as to 
 
 FIG. 244 
 
 bring it within practical limits, while at the same time the 
 power value of the steam is utilized to a high degree of 
 efficiency. 
 
 The speed of the Westinghouse-Parsons turbine varies 
 from about 750 K. P. M. for a 5,000 K. W. machine, to 
 3,600 E. P. M. for a 400 K. W. turbine. 
 
 19 
 
20 Steam Engineering 
 
 The Westinghouse-Parsons turbine is fundamentally 
 based upon the invention of Mr. Charles A. Parsons, who, 
 while experimenting with a reaction turbine constructed 
 along the lines of Hero's engine, conceived the idea of 
 combining the two principles, reaction and impulse, and 
 also of causing the steam to flow in a general direction 
 parallel with the shaft of the turbine. This principle of 
 parallel flow is common to all four types of turbines, but 
 is perhaps more prominent in the Westinghouse-Parsons, 
 and less so in the De Laval. 
 
 Fig. 235 shows a general view of four Westinghouse- 
 Parsons steam turbines, and Fig. 244 shows a 600 H. P. 
 machine with the upper half of the cylinder, or stator as it 
 is termed, thrown back for inspection. Fig 245 is a sec- 
 tional view of a Westinghouse-Parsons turbine, and it will 
 be noticed that there are three sections or drums, gradually 
 increasing in diameter from the inlet A, to the third and 
 last group of blades. This arrangement may be likened 
 in some measure to the triple compound reciprocating 
 engine. 
 
 Fig. 246 shows the complete revolving part of a 3,000 
 H. P. turbine. Its weight is 28,000 Ibs., length over all 
 19 feet 8 inches, and 12 feet 3 inches between bearings; 
 the largest diamater, 6 feet. 
 
 By reference to Fig. 244 it will be seen that the inside 
 of the cylinder is studded with rows of small stationary 
 blades, and that the rotor or revolving part of the ma- 
 chine is also fitted with rows of small blades, similar in 
 shape and dimensions to the stationary blades. When the 
 upper half of the cylinder is in position, each row of sta- 
 tionary blades fits in between two corresponding rows of 
 moving blades. This arrangement may perhaps be better 
 
Westinglwusc-P arsons Turbine 
 
 21 
 
 FIG. 245 
 SECTION OF STANDARD WESTINGHOUSE SINGLE FLOW TURBINE 
 
22 
 
 Steam Engineering 
 
 understood by reference to Fig. 247, which illustrates the 
 relation of the stationary blades to the moving blades when 
 in position, and also shows by the arrows the course of the 
 steam and its change of direction caused by the stationary 
 blades. 
 
 For the purpose of explanation the moving blades or 
 vanes may be considered as small curved paddles pro- 
 jecting from the surface of the rotor, and there is a large 
 number of them, as for instance, taking a 400 K. W. ma- 
 chine, there are 16,095 moving blades and 14,978 sta- 
 tionary blades, a total of 31,073. 
 
 FIG. 246 
 
 The stationary vanes, as previously explained project 
 from the inside surface of the cylinder. Both stationary 
 and moving vanes are similar in shape, and are made of 
 hard drawn material, and they are set into their places 
 and secured by a caulking process. The blades vary in size 
 from y 2 to 7 in. in length, according to where they are 
 used. Referring to Fig. 24-4, it will be observed that the 
 shortest blades are placed at what might be termed the 
 steam end of each section or drum of the rotor and cylinder, 
 and that their length gradually increases, corresponding 
 
Westing house-Parsons Turbine 23 
 
 with the increased volume of steam, until a mechanical 
 limit is reached, when a new group of blades begins on a 
 succeeding drum of larger diameter. Eeferring to Fig. 
 24:7, which is a sectional view of four rows of blades, it will 
 be noticed that all the blades, whether stationary or mov- 
 ing, have the same curvature. Also that the curves are set 
 opposite each other. The reason for this will be apparent 
 as the diagram is studied. The steam at pressure P first 
 comes in contact with row 1 of stationary blades. It 
 expands through this row, and in expanding the pressure 
 falls to P'. 
 
 STATIONARY BLADES 
 
 MOVING BLADES 
 
 3 
 
 4 
 
 J J D B . 
 
 STATIONARY BLADES 
 
 'ING BLADES 
 
 FIG. 247 
 
 The energy in the steam is converted into velocity, and 
 it impinges upon row 2 of moving blades, driving them 
 around in their course by impulse. A second expansion 
 now occurs in row 2, and again the energy is converted into 
 velocity, but this time the reaction of the steam as it leaves 
 the blades of row 2 also tends to impel them around in 
 their course. The moving blades thus receive motion from 
 two causes the one due to the impulse of the steam strik- 
 ing them, and the other due to the reaction of the steam 
 leaving them. 
 
24 Steam Engineering 
 
 This cycle is repeated in rows 3 and 4, and so on through- 
 out the length of the rotor until the exhaust end is reached. 
 
 It should be noted that the general direction taken by 
 the steam in its passage through the turbine is in the form 
 of a spiral or screw line about the rotor. The clearance 
 between the blades as they stand in the rows is % in. for 
 the smallest size blades and % in. f r the larger ones, 
 gradually increasing from the inlet to the exhaust. In the 
 5,000 K. W. machine the clearance at the exhaust end be- 
 tween the rows of blades is 1 in. It will thus be seen that 
 there is ample mechanical clearance, also allowance for 
 lateral motion for adjustment of the rotor, although this is 
 very slight, as the rotor is balanced at all loads and pres- 
 sures by the balancing pistons PPP, Fig. 245, to which 
 reference is now made. These pistons revolve within the 
 cylinder, but do not come in mechanical contact with it; 
 consequently there is no friction. The diameter of each 
 piston corresponds to the diameter of one of the three 
 drums. 
 
 The steam entering the chamber A through valve V 
 presses against the turbine blades and goes through doing 
 work by reason of its velocity. It also presses equally in 
 the opposite direction against the first piston P, and so 
 the shaft or rotor has no end thrust. On leaving the first 
 group of blades and striking the second group the pressure 
 in either direction is again equalized by the balance port 
 E allowing the steam to press against the second balance 
 piston P. The same event occurs at group three, the 
 steam acting upon the third piston P. 
 
 The areas of the balancing pistons are such that, no 
 matter what the load may be, or what the steam pressure 
 or exhaust pressure may be, the correct balance is main- 
 
Westinghouse-Parsons Turl ine 25 
 
 tained and there is practically no end thrust. Below is 
 shown a pipe E connecting the back of the balancing pis- 
 tons with the exhaust chamber. This arrangement is for 
 the purpose of equalizing the pressure at this point with 
 the pressure in the exhaust chamber. 
 
 It might be thought that the blades, on account of their 
 being so light and thin, would wear out very fast, but ex- 
 perience so far shows that they do not. This may be ac- 
 counted for in two ways. First, the reduction of the 
 velocity of the steam, the highest velocity in the Parsons 
 turbine not exceeding 600 ft. per second; secondly, the 
 light steam thrust on each blade, said to be equal to about 
 1 oz. avoirdupois. This is far within the bending strength 
 of the material. A steam strainer is also placed in the 
 admission port, to prevent all foreign substances from en- 
 tering the turbine. 
 
 A rigid shaft and thrust or adjustment bearing accu- 
 rately preserves the clearances, which are larger in +his 
 turbine than in other types, owing to the fact that the 
 entire circumference of the turbine is constantly filled 
 with working steam when in operation. 
 
 The bearings shown in Fig. 245 are constructed along 
 lines differing from those of the ordinary reciprocating 
 engine. The bearing proper is a gun metal sleeve, see Fig. 
 248, that is prevented from turning by a loose-fitting 
 dowel. Outside of this sleeve are three concentric tubes 
 having a small clearance between them. This clearance is 
 kept constantly filled with oil supplied under light pres- 
 sure, which permits a vibration of the inner shell or sleeve 
 and at the same time tends to restrain or cushion it. This 
 arrangement allows the shaft to revolve about its axis of 
 gravity, instead of the geometrical axis, as would be the 
 
26 
 
 Steam Engineering 
 
 case if the bearing were of the ordinary construction. The 
 journal is thus to a certain degree a floating journal, free 
 to run slightly eccentric according as the shaft may hap- 
 pen to be out of balance. 
 
 FIG. 248 
 
 A flexible coupling is provided, by means of which the 
 power of the turbine is transmitted to the dynamo or other 
 machine it is intended to run. The oil from all the bear- 
 
Westinghouse-P arsons Turbine 27 
 
 ings drains back into a reservoir, and from there it is forced 
 up into a chamber, where it forms a static head, which 
 gives a constant pressure of oil on all the bearings. A 
 secondary valve is located at Vs, by means of which high 
 pressure steam may be admitted to the steam space E on 
 the same principle that high pressure steam is admitted to 
 the low pressure cylinder of a compound engine. This 
 valve opens automatically in cases of emergency, such as 
 overload, failure of the condenser to work, etc. 
 
 The shaft, where it passes through either cylinder head, 
 is packed with a water seal packing, consisting of a small 
 paddle wheel attached to the shaft, which, through centri- 
 fugal action, maintains a static pressure of about 5 Ibs. per 
 sq. in. in the water seal, thus preventing all leakage while 
 at the same time it is frictionless. 
 
 Governor. The speed of the Westinghouse-Parsons tur- 
 bine is regulated by a fly ball governor constructed in such 
 manner that a very slight movement of the balls serves to 
 produce the required change in the supply of steam. Fig. 
 249 is a diagram of the governor mechanism. The ball 
 levers swing on knife edges instead of pins. The gover- 
 nor works both ways, that is to say, when the levers are 
 oscillating about their mid position a head of steam corre- 
 sponding to full load is being admitted to the turbine, and 
 a movement from this point, either up or down, tends to 
 increase or to decrease the supply of steam. 
 
 Referring to Fig. 249, B is a piston directly connected 
 to the admission valve. Steam is admitted to this piston 
 under control of the pilot valve A, which has a slight but 
 continuous reciprocating motion derived from the eccentric 
 rod C, and the function of the governor is to vary the plane 
 of oscillation of this valve, thus causing it to admit more 
 
28 Steam Engineering 
 
 or less steam to piston B. The admission valve, being 
 actuated exclusively by piston B, is thus caused to remain 
 open for a longer or shorter period of time, according to 
 the load upon the turbine. 
 
 The vibrations of the admission valve, although very 
 slight, are continuous and regular, about 165 per minute, 
 and are transmitted primarily by means of an eccentric, 
 the rod of which is shown at C, Fig. 249. 
 
 FIG. 249 
 
 The governor sleeve is used as a floating fulcrum, and 
 the points D and E are fixed. By means of this very 
 ingenious device the steam is admitted to the turbine in 
 puffs, either long or short, according to the demand for 
 steam. At full load the puffs merge into an almost con- 
 tinuous blast. "When the load has increased to the point 
 where the valve is wide open continuously, a full head of 
 steam is being admitted. Beyond this the secondary valve 
 comes into action, thus keeping the speed up to normal. 
 
Westinghouse-Parsons Turbine 29 
 
 The rotor requires perfect balancing to insure quiet 
 running, but this is easily accomplished in the shop by 
 means of a balancing machine used by the builders. 
 
 Steam turbines generally show higher efficiency in the 
 use of steam than reciprocating engines do, and this fact 
 is due to three leading causes. First, it is possible with 
 the turbine to use highly superheated steam which, owing 
 to the difficulties attending lubrication, could not be used 
 in the reciprocating engine. Second, a larger proportion of 
 the heat contained in the steam is converted into work, for 
 
 FIG. 250 
 NEW BLADING MATERIAL 
 
 the reason that the steam is allowed to expand to a much 
 lower pressure, and into a higher vacuum. In addition to 
 this, the velocity of the expanding steam is utilized in a 
 much higher degree in the turbine as compared with the re- 
 ciprocating engine. Third, mechanical friction or lost 
 work is reduced to the minimum. Under test a 400 K. W. 
 Westinghouse-Parsons steam turbine, using steam at 150 
 Ibs. initial pressure and superheated about 180, consumed 
 11.17 Ibs. of steam per brake horse power hour at full load. 
 The speed was 3,550 R. P. M. and the vacuum was 28 in. 
 
30 Steam Engineering 
 
 With dry saturated steam the consumption was 13.5 Ibs. 
 per B. H. P. hour at full load, and 15.5 Ibs. at one-half 
 load. 
 
 A 1,000 K. W. machine, using steam of 150 Ibs. pres- 
 sure and superheated 140, exhausting into a vacuum of 
 28 in., showed the very remarkable economy of 12.66 Ibs 
 of steam per E. H. P. per hour. 
 
 A 1,500 K. W. Westinghouse-Parsons turbine, using dry 
 saturated steam of 150 Ibs. pressure with 27 in. vacuum, 
 consumed 14.8 Ibs. steam per E. H. P. hour at full load, 
 and 17.2 Ibs. at one-half load. 
 
 The Westinghouse machine company have recently in- 
 troduced a new blade material which is now used in all 
 Westinghouse turbines. It is a copper-coated steel blade, 
 or, as designated by the builder, "Monnot metal." in which 
 the copper coating (seen in Fig. 250) is chemically welded 
 to the steel so thoroughly that the blades can be drawn to 
 the desired shape from the original ingot, without weaken- 
 ing the union between the copper and steel. The process 
 of drawing makes the copper coating somewhat thicker at 
 the inlet and outlet edges of the blade, though the remain- 
 ing portions of the blade surfaces are coated with an abso- 
 lutely uniform thickness of copper. The only portion of 
 the blade where steel is exposed, is the small surface of the 
 tip of the blade where, however, corrosion is the least detri- 
 mental, for should the tips corrode, the copper coating 
 would still remain intact, thus leaving the working blade 
 surfaces untouched and the blade clearances unaltered. 
 
 Figs. 251 and 252 show sectional elevations of the double 
 flow type of steam turbines now being manufactured by the 
 Westinghouse company, in addition to the standard single 
 flow turbine already described. 
 
Westinghoitse-Parsons Turbine 
 
 31 
 
 FIG. 251 
 SECTION OF WESTINGITOrSE DOUBLE FLOW TURBINE 
 
32 
 
 Steam Engineering 
 
 FIG. 252 
 
 WESTINGHOUSE DOUBLE FLOW LOW-PRESSURE TURBINE 
 Sectional Elevation 
 
 Fig. 251 shows the machine as adapted for using steam 
 of high initial pressure, in fact an impulse turbine, in which 
 the steam admitted first to the nozzle block, is expanded 
 
Westinghouse-Parsons Turbine 33 
 
 in nozzles arranged about the periphery, and impinges 
 upon the impulse buckets of the central rotation wheel. 
 There are two rows of moving blades upon the impulse 
 wheel, with an intermediate set of reversing blades as 
 shown. Issuing from the delivery side of this wheel with 
 its velocity energy practically all abstracted, the steam 
 passes, as shown by the arrow, to an intermediate set of 
 Parsons blading. As this blading has no counterpart upon 
 the other side of the turbine, the pressure upon it must be 
 counterbalanced, and this is done by making the extension 
 of the hub by which the impulse wheel is keyed to the shaft, 
 into a piston or dummy of the mean diameter of the inter- 
 mediate stage, as shown at P. After passing the inter- 
 mediate stage the steam divides, one portion passing 
 directly to the low-pressure blading at the left, while the 
 rest passes through the hollow shell of the rotor to the 
 similar pressure blades upon the right. As these sections 
 are equal and symmetrical they counterbalance each other, 
 so that no further dummies are required than the small 
 one already referred to. 
 
 For regulating the steam supply in accordance with the 
 load, two methods other than that of simple throttling with 
 its sacrifice of temperature head are available. 
 
 The admission area may be varied by the cutting in and 
 out of nozzles. 
 
 The duration of the time of admission through a con- 
 stant area may be varied. 
 
 The first is the Curtis method, impracticable for a full- 
 admission turbine like the Parsons ; the second, that which 
 has been developed by the Westinghouse engineers for the 
 Parsons as they build it. The adoption of the partial ad- 
 mission for first stage in the double flow machine gave the 
 
34 Steam Engineering 
 
 Westinghouse designers their option of the two method* 5 , 
 but they have preferred to continue the variable dura I ion 
 puff system, already described in connection with single 
 flow machines. A disadvantage of the variable nozzle 
 method of regulation is, that if the area of the nozzles of 
 the succeeding stages is correctly proportioned to pass 
 along the steam admitted by a certain number of primary 
 nozzles, it will be too great when fewer nozzle* are in 
 action, and too small when there are more. This will 
 result in a considerable variation of the pressure in the 
 succeeding stages, and of the pressure ratios of expansion 
 and jet velocity acquired in those stages, and interfere 
 with the designer's intention with regard to the distribu- 
 tion of work and the relation of blade to jet velocity. This 
 could be overcome only by adjusting the nozzles of the suc- 
 ceeding individual stages in harmony with those of the 
 initial stage. 
 
 If, on the other hand, the passages through the turbine 
 are permanently arranged in the correct relation to each 
 other, this relation will persist whether the How is con- 
 tinuous or intermittent, and the energy developed can be 
 regulated to the demand by making the flow more nearly 
 continuous, as the load approaches the rated capacity of 
 the machine. So far as the change in initial pressure due 
 to the alternate letting on and shutting off of the steam is 
 concerned, theory indicates, and experiment proves that 
 where the expansion in each stage is but a small part of 
 the total range, as in the Parsons turbine, the initial and 
 terminal pressures of each stage rise and fall, resulting in 
 a fairly constant pressure ratio at each successive expan- 
 sion; in other words, for small ranges, and throttle gov- 
 erning, the nozzle and blade areas are reasonably correct 
 
Westingliouse-Parsons Turbine 35 
 
 through a wide range of load and pressure distribution. 
 For this reason the impulse section of the Westinghouse 
 turbine, doing, say, only one-fifth of the total work, is 
 properly proportioned for a wide range in load and may be 
 governed without resorting to intermediate nozzle control, 
 and without sacrifice of economy and fractional loads. 
 
 Advantage Gained. The balancing pistons have been re- 
 duced to a minimum. In the single-flow types the high- 
 pressure dummy occupies fully one-half of the total dummy 
 piston length on the shaft, while the low-pressure piston 
 is 2y 2 times the high-pressure diameter. 
 
 A reduction of nearly 50 per cent in shaft span between 
 bearings. Owing to the rotor construction a better loading 
 of the shaft is also obtained; that is, the rotor weight is 
 transmitted to the shaft at points nearer the bearings than 
 in the single-flow rotor, where the weight is largely dis- 
 tributed. 
 
 An increase to about double rotative speed made possible 
 by the reduction in shaft span, and loading; that is, to a 
 general greater rigidity of the double-flow construction. 
 
 A reduction of about 70 per cent in the bulk of the main 
 parts of the machine with practically the same output. 
 
 Internal cylinder stresses due to high-pressure and high- 
 temperature steam are avoided by isolating the incoming 
 steam within separate nozzle chambers, so that the main 
 body of the turbine is subjected to steam having not much 
 over 75 pounds gauge pressure with practically no super- 
 heat. 
 
 The bulk of the low-pressure stage is better distributed 
 and the length of the low-pressure blades greatly reduced 
 by subdividing this stage into two parts located at opposite 
 ends of the rotor. 
 
 As will be plain from what has preceded, the advantages 
 
36 
 
 Rieam Engineering 
 
 sought in this form of turbine are constructional and me- 
 chanical rather than economic. For high-pressure work 
 the standard Westinghouse-Parsons single-flow turbine will 
 be built up to capacities of 3,000 kilowatts; above 5,000 
 kilowatts all units will be built upon the double-flow prin- 
 
 FIG. 253 
 3,000 K. W. WESTINGHOUSE DOUBLE FLOW STEAM TURBINE 
 
 ciple. The latter construction will also be used for the 
 low-pressure turbines to which it is so admirably adapted, 
 as shown in Fig. 252, which is a section of the Westing- 
 house low-pressure, double-flow, steam turbine designed 
 for utilizing the exhaust steam 4 from non-condensing recip- 
 rocating engines. Fig. 253* shows a view of a double-flow 
 steam turbine without the generator attached. 
 
UNIVERSITY 
 
 OF 
 
 The Curtis Steam Turbine 
 
 In the Curtis turbine the heat energy in the steam is 
 imparted to the wheel, both by impulse and reaction, but 
 the method of admission differs from that of the Westing- 
 house-Parsons, in that the steam is admitted through ex- 
 panding nozzles in which nearly all of the expansive force 
 of the steam is transformed into the force of velocity. The 
 steam is caused to pass through one, two, or more stages 
 of moving elements, each stage having its own set of ex- 
 panding nozzles, each succeeding set of nozzles being greater 
 in number and of larger area than the preceding set. The 
 ratio of expansion within these nozzles depends upon the 
 number of stages, as, for instance, in a two-stage machine, 
 the steam enters the initial set of nozzles at boiler pres- 
 sure, say 180 Ibs. It leaves these nozzles and enters the 
 first set of moving blades at a pressure of about 15 Ibs., 
 from which it further expands to atmospheric pressure in 
 passing through the wheels and intermediates. From the 
 pressure in the first stage the steam again expands through 
 the larger area of the second stage nozzle to a pressure 
 slightly greater than the condenser vacuum at the entrance 
 to the second set of moving blades, against which it now 
 impinges, and passes through still doing work, due to 
 velocity and mass. 
 
 From this stage the steam passes to the condenser. If 
 the turbine is a four-stage machine and the initial pressure 
 is 180 Ibs., the pressure at the different stages would be dis- 
 tributed in about the following manner : Initial pressure, 
 180 Ibs.; first stage, 50 Ibs.; second stage, 5 Ibs.; third 
 
 37 
 
38 
 
 Steam Engineering 
 
 stage, partial vacuum, and fourth stage, condenser vacuum. 
 
 Fig. 254 gives a general view of a 5,000 K. W. turbine 
 
 and generator. The generator is shown at the top, while 
 
 the turbine occupies the middle and lower section. A por- 
 
 FIG. 254 
 
 5,000 K. W. CURTIS STEAM TURBINE DIRECT CONNECTED TO 5.000 K. W. 
 THREE-PHASE ALTERNATING CURRENT GENERATOR 
 
 tion of the inlet steam l pipe is shown, ending in one nozzle 
 group at the side. There are three groups of initial noz- 
 zles, two of which are not shown. The revolving parts of 
 this unit are set upon a vertical shaft, the diameter of the 
 
The Curtis Turbine , 39 
 
 shaft corresponding to the size of the unit. For a machine 
 having the capacity of the one illustrated by Fig. 254 the 
 diameter of the shaft is 14 in. 
 
 The shaft is supported by, and runs upon a step bearing 
 at the bottom. This step bearing consists of two cylindrical 
 cast iron plates, bearing upon each other and having a 
 central recess between them into which lubricating oil is 
 forced under pressure by a steam or electrically driven 
 pump, the oil passing up from beneath. A weighted ac- 
 cumulator is sometimes installed in connection with the 
 oil pipe as a convenient device for governing the step bear- 
 ing pumps, and also as a safety device in case the pumps 
 should fail, but it is seldom required for the latter pur- 
 pose, as the step bearing pumps have proven, after a long 
 service in a number of cases, to be reliable. The vertical 
 shaft is also held in place and kept steady by three sleeve 
 bearings, one just above the step, one between the turbine 
 and generator, and the other near the top. These guide 
 bearings are lubricated by a standard gravity feed system. 
 It is apparent that the amount of friction in the machine 
 is very small, and as there is no end thrust caused by the 
 action of the steam, the relation between the revolving and 
 stationary blades may be maintained accurately. As a con- 
 sequence, therefore, the clearances are reduced to the mini- 
 mum. 
 
 The Curtis turbine is divided into two or more stages, 
 and each stage has one, two or more sets of revolving 
 blades bolted upon the peripheries of wheels keyed to the 
 shaft. There are also the corresponding sets of stationary 
 blades, bolted to the inner walls of the cylinder or casing. 
 As in the Westinghouse-Parsons type, the function of the 
 stationary blades is to give direction to the flow of steam. 
 
40 
 
 Steam Engineering 
 
 Fig. 255 illustrates one stage of a 500 K. W. turbine in 
 course of construction. It will be observed that there are 
 three wheels, and that in the spaces between these wheels 
 the stationary buckets or vanes are placed, being firmly 
 bolted to the casing. Fig. 256 shows sections of both 
 revolving and stationary buckets ready to be placed in 
 
 FIG, 255 
 500 K. W. CUBTIS STEAM TURBINE IN COUBSE OF CONSTRUCTION 
 
 position. The illustration in Fig. 255 shows the lower or 
 last stage. The clearance between the revolving and sta- 
 tionary blades is from -fa to T V in., thus reducing the 
 wasteage of steam to a very low percentage. The diameters 
 of the wheels vary according to the size of the turbine, 
 that of a 5,000 K. W. machine being 13 ft. 
 
The Curtis Turbine 
 
 41 
 
 REVOLVING BUCKETS FOR CURTIS STEAM TURBINE 
 
 STATIONARY BUCKETS P'OR CURTIS STEAM TURBINE 
 
 FIG. 256 
 
 Fig. 257 shows a nozzle diaphragm with its various 
 openings, and it will be noted that the nozzles are set at 
 an angle to the plane of revolution of the wheel. 
 
42 
 
 Steam Engineering 
 
 Fig. 258 is a diagram of the nozzles, moving blades and 
 stationary blades of a two-stage Curtis steam turbine. The 
 steam enters the nozzle openings at the top, controlled by 
 
 cccccccccccccccccccccc 
 
 ll\\ 
 
 FIG. 258 
 DIAGRAM OF NOZZLES AND BUCKETS IN CURTIS STEAM TURBINE 
 
 the valves shown, the regulation of which will be explained 
 later on. In the cut Fig. 258 two of the valves are open, 
 and the course of the steam through the first stage is indi- 
 
The Curtis Turbine 43 
 
 cated by the arrows. After passing successively through 
 the different sets of moving blades and stationary blades 
 in the first stage, the steam passes into the second steam 
 chest. The flow of steam from this chamber to the second 
 stage of buckets is also controlled by valves, but the func- 
 tion of these valves is not in the line of speed regulation, 
 but for the purpose of limiting the pressure in the stage 
 chambers, in a manner somewhat similar to the control of 
 the receiver pressure in a two-cylinder or three-cylinder 
 compound reciprocating engine. 
 
 The valves controlling the admission of steam to the 
 second, and later stages differ from those in the first group 
 in that tl.ey partake more of the nature of slide valves and 
 may be operated either by hand, or automatically ; in fact, 
 they require but very little regulation, as the governing 
 is always done by the live steam admission valves. 
 
 Action of the Steam in a Two-stage Machine. As prev- 
 iously stated, the steam first strikes the moving blades in 
 the first stage of a two-stage machine at a pressure of about 
 15 Ibs. above atmospheric pressure, but with great velocity. 
 From this wheel it passes to the set of stationary blades 
 between it and the next lower wheel. These stationary 
 blades change the direction of flow, of the steam and cause 
 it to impinge the buckets of the second wheel at the proper 
 angle. 
 
 This cycle is repeated until the steam passes from the 
 first stage into the receiving chamber, or steam chest for the 
 second stage. Its passage from this chamber into the 
 second stage is controlled by valves, which, as before stated, 
 a iv regulated either by hand, or automatically. The course 
 of the steam through the nozzles and blades of the second 
 stage is clearly indicated by the arrows, and it will be 
 noted that steam is passing through all the nozzles. 
 
44 . Steam Engineering 
 
 At this point it might be well to consider the question 
 which no doubt arises in the mind of the student in his 
 efforts to grasp the underlying principles in the action of 
 the steam turbine. Why is it that the impingement of the 
 steam, at so low a pressure, against the blades or buckets 
 of the turbine, imparts such a large amount of energy 
 to the shaft? 
 
 The answer is, because of velocity, and a good example 
 of the manner in which velocity may be made to increase 
 the capacity of an agent to do work is illustrated in the 
 following way : Suppose that a man is standing within 
 arm's length of a heavy plate glass window and that he 
 holds in his hand an iron ball weighing 10 Ibs. Suppose 
 the man should place the ball against the glass and press 
 the same there with all the energy he is capable of exerting. 
 He would make very little, if any, impression upon the 
 glass. But suppose that he should walk away from the 
 window a distance of 20 ft, and then exert the same amount 
 of energy in throwing the ball against the glass, a different 
 result would ensue. The velocity with which the ball wouW 
 impinge the surface of the glass would no doubt ruin the 
 window. Now, notwithstanding the fact that weight, energy 
 and time involved were exactly the same in both instances, 
 yet a much larger amount of work was performed in the 
 latter case, owing to the added force imparted to the ball 
 by the velocity with which it impinged against the glass. 
 
 Speed Regulation. The governing of speed is accom- 
 plished in the first set of nozzles, and the control of the 
 admission valves here is effected by means of a centrifugal 
 governor attached to the top end of the shaft, This gover- 
 nor, by a very slight movement, imparts motion to levers, 
 which in turn work the valve mechanism. The admission 
 
Tlic Curd* Tin-line 
 
 45 
 
 of steam to the nozzles is controlled by piston valves, which 
 are actuated by steam from small pilot valves which are in 
 turn under the control of the governor Fig. 259 shows the 
 
 . 
 
 FIG. 259 
 
 GOVERNOR FOR 5.000 K. W. TURBINE 
 
 form a governor for a 5,000 K. W. turbine, and Fig. 260 
 shows the electrically operated admission valves for one 
 set of nozzles. 
 
4-n 
 
 Engineering 
 
 Speed regulation is affected by varying the number of 
 nozzles in flow, that is for light loads fewer nozzles are open, 
 and a smaller volume of steam is admitted to the turbine 
 wheel, but the steam that is admitted impinges the moving 
 blades with the same velocity always, no matter^ whether 
 the volume be large or small. With a full load and all the 
 nozzle sections in flow, the steam passes to the wheel in a 
 broad belt and steady flow. 
 
 FIG. 200 
 ELECTRICALLY OPERATED VALVE 
 
 In addition to the method just described, of actuating 
 the addmission valves by steam, the General Electric Com- 
 pany, manufactures of the Curtis Turbine, have recently 
 introduced a system of hydraulicaly operated valves for 
 speed regulation. 
 
 These valves are also of the poppet type, and each i? 
 closed by a helical spring in compression. In the closed 
 position they are held tight by steam pressure, against 
 which they are openedi The valves on one machine are all 
 
The Curtis Turbine 
 
 r 
 
 duplicates, and are opened in rotation by cams (one for 
 each valve) mounted on a shaft, each cam being given in 
 succession an angular advance over its predecessor. This 
 
 n i :i 
 
 FIG. 261 
 
 cam shaft is rotated by the piston in a hydraulic cylinder, 
 the cylinder being mounted either on the generator or 
 valve casing. 
 
48 Steam Engineering 
 
 The valves open gradually; that is there will be throt- 
 tling on the 'opening, or closing valve, before the next one 
 in either side is opened or closed, so that the exact amount 
 of steam required can be admitted for any definite load. 
 Fig. 261 shows a section of the hydraulic cylinder, and 
 controlling valve. The position of piston A is controlled 
 by a balanced piston valve B. The liquid under pressure 
 is admitted at C, and discharged at D. The rod E is con- 
 nected with the governor, and rod F with the piston rod. 
 
 Operation. The rod E receives its motion from the 
 governor, and occupies a fixed position for any given speed 
 between the limits through which the governor is designed 
 to operate. The lever arms G and G', and H and H' are 
 so proportioned that the piston A will occupy a definite 
 fixed position to correspond with any position of rod E. 
 
 Therefore as the crosshead K transmits its motion 
 through connecting rod N; (see Fig. 262) to the crank 
 L on the cam shaft M, there will be a fixed number of 
 valves open for any position of the governor. While the 
 turbine is operating at a fixed speed, the piston valve will 
 occupy a central position, closing both ports and P. 
 When there is a drop in speed, the governor causes rod E 
 to move down, thus opening part to discharge, and port 
 P to admit liquid under piston A which them moves up- 
 wards, opening more valves to satisfy the demand for steam. 
 In moving up the piston transmits its motion through rod 
 F to the piston valve B, restoring it to the central position. 
 When operating on a fixed, or slightly varying load, the 
 main piston should not continuously move over a distance 
 greater than that corresponding to the lap of the piston 
 valve, and under no condition of governing should the 
 main piston continually travel back and forth over a dis- 
 
The Curtis Turbine 
 
 49 
 
 FIG. 262 
 
 tance greater than this. Any larger movements should 
 only occur when greater or less power is demanded for 
 
50 Steam Engineering 
 
 considerable variation in load. Any continuous opening 
 and closing of the valves during a steady load is an indi 
 cation of excessive friction in the governor rigging, or pis- 
 ton valve, and it should be eliminated as soon as possible. 
 
 It is essential that the pistons on the piston valve B, 
 Fig. 261 be reduced in diameter at their centers -^ in. 
 as indicated in the illustration. If this is not done it may 
 be responsible for sticking of the piston valve, thereby in- 
 terfering with the satisfactory regulation of the machine. 
 
 For different machines the connections may be altered, 
 and in some the operation is reversed, by crossing the ports, 
 so that the piston A will move in the same direction as the 
 piston valve B, and. in the application of the gear to later 
 machines of large capacity, it has been found advisable to 
 place the cylinder horizontal, operating crank shafts of 
 valve casings by means of rack and pinion with bevel gear 
 transmission, or with racks operating directly on pinions 
 on cam shafts,, but the principle of operation is the same, 
 only modified in application to suit particular cases. 
 
 Adjustment. With the piston A, and the piston valve 
 B, both in their mid positions, the rod F should be of such 
 a length that the lever Gr will be horizontal. The connect- 
 ing rod N is adjusted so that with piston A at the extreme 
 end of its up stroke, all the steam valves are open, and the 
 first one just ready to close. With the piston A in this 
 position (i. e., at the extreme end of its stroke,) and the 
 governor at the low speed position, the rod E should be 
 adjusted so that the piston valve B, will be in its mid 
 position. . 
 
 Precautions. (1) It is absolutely essential that all con- 
 nections between governor and valve be entirely free from 
 friction. 
 
The Curtis Turbine 51 
 
 (2) The piston valve B must move freely for the whole 
 length of its stroke, so that if the rod E be disconnected 
 from the arm G, the valve will drop of its own weight, 
 either with pressure on or off. 
 
 (3) There must be absolutely no binding at any of the 
 joints through the whole travel. 
 
 (4) The liquid used must be entirely free from dirt, or 
 grit, of any nature. 
 
 (5) On the main steam valves; in the closed position, 
 when the roller has ridden off of the cam, it must not press 
 on the cam shaft, as this will prevent valve seating properly. 
 
 (6) The piston valve and bore must be perfectly round 
 and absolutely straight, or an excessive leakage will be 
 established on one side of the valve, causing it to bind. 
 
 (7) The pressure exerted by the main valve springs in 
 the open position must be in excess of that sufficient to 
 overcome steam pressure on rod, and any friction that may 
 exist in packing. 
 
 (8) The plate below main valve springs must be a slid- 
 ing fit in guides at all temperatures. 
 
 (9) Care must be taken in the adjustment of the length 
 of the rods E and F, that in no position of the governor, or 
 piston, can the piston valve become jammed at the end of 
 its stroke. 
 
 (10) A heavy oil must not be used or the action will be 
 sluggish. 
 
 Piping. Fig. 263 shows a diagram of piping for a ma- 
 chine using oil to operate the valves. This is supplied by the 
 same pumps that furnish lubrication for the guide bearings. 
 A relief valve E, is adjusted to the desired pressure for 
 operating the gear. When the speed is constant and the 
 valve not taking any oil, the excess supplied by pumps will 
 be discharged through this relief valve. 
 
52 Steam Engineering 
 
 The special reducing valve shown in Fig. 264, and at S, 
 Fig. 263, is provided to control the amount of oil supplied 
 to the bearings. 
 
 This valve can be closed, or adjusted over a wide range, by 
 altering the effective length of baffler. 
 
 Referring to Fig. 263, the tank marked "air chamber" is 
 
 fte/iefVatvf 
 
 provided in order to give a reserved capacity of oil should 
 the pumps for any reason stop, and also to form an air 
 cushion on the system. The valve at the top of this tank 
 should be kept closed, and the oil allowed to compress the 
 air contained in the tank, and from time to time the tank 
 should be completely emptied and refilled with air. The 
 
The Curtis Turbine 
 
 53 
 
 emptying can be easily accomplished by opening the three- 
 way valve to discharge to the oil tank. This need not in- 
 terfere with the operation of the machine. After the air 
 chamber is emptied, valve J should be closed, and the three- 
 way valve open to admit oil to the chamber. 
 
 C 
 
 FIG. 264 
 
 In installations where oil is used for the turbine step 
 bearing, oil for the operating gear and bearings may be 
 taken from the high pressure pipe line, on the pump side 
 of the step baffler, through a reducing valve. The piping 
 
54 
 
 Steam Engineering 
 
 system remains as shown diagramatically in Fig. 263 except 
 for change in source of supply of operating fluid. 
 
 In case the station installation includes an air compres- 
 
 FIG. 265 
 
 sor, this equalizing tank may be piped in the system, the 
 connection being made on the side of the tank (as provided 
 for). The refilling of the tank is thus much simplified, 
 and its capacity for emergency operation greatly increased. 
 
The Curtis Turbine 55 
 
 Care should be taken to insure tightness of both valve con- 
 trolling air supply to tank, and pet cock at the top. 
 
 Step Bearing. Fig. 265 is a section through the cast iron 
 step blocks. The lower block in the illustration has two 
 holes drilled in it to match the two dowel pins seen project- 
 ing from the other block. There is another hole through 
 the center of the lower block threaded for %" pipe The 
 step lubricant (oil or water) is forced up through this hole, 
 and out between the raised edges in a film, thus floating the 
 rotating elements of the turbine on a frictionless disk of 
 lubricant. The upper side of the top step block is counter- 
 bored to fit the lower end of the turbine shaft, in which 
 there is also a slot for the reception of a key that is fitted 
 across the top end of the step block. 
 
 The counterbore centers the block, the dowel-pins guide 
 the key into the slot, and the key causes the block to turn 
 with the shaft. These are all close fits, and when it be- 
 comes necessary to remove the block for inspection or re- 
 pairs, it must be pulled off by means of a screw introduced 
 into a threaded hole in the under side of the lower block. 
 The whole is supported by, and rests upon a large screw that 
 passes up through a block of cast-iron which has a threaded 
 bronze bushing that forms the nut for the screw. The 
 large block termed the cover plate is held to the base of the 
 turbine by eight l l /o inch cap screws. A good idea of the 
 construction may be gained by reference to Fig. 266 which 
 is a section of the lower portions. It will be noticed that the 
 % in. oil supply pipe passes up through the entire length 
 of the large step supporting screw, and connects with the 
 oil passage through the lower step block. 
 
 Clearance. With the Curtis turbine, the matter of clear- 
 ance is very important. There must be no rubbing contact 
 
56 
 
 Steam Engineering 
 
 between the revolving and stationary buckets. Neither 
 must there be too much clearance. Provision is therefore 
 made for inspection, and adjustment of the clearance in the 
 following manner. A two inch hole is drilled and tapped 
 
 OilDraln 
 
 Steam 
 
 FIG. 266 
 
 into each stage, sometimes opposite a row of moving blades 
 and sometimes opposite the stationary blades. 
 
 Two inch plugs are screwed into these holes, to be re- 
 moved when an inspection is to be made. The clearance is 
 
The Curtis Turbine 57 
 
 not uniform in all the stages, but is least in the first stage, 
 and greatest in the last. The clearances in each stage of a 
 1500 K W machine for instance are as follows : 1st stage 
 0.06 to 0.08, 2nd stage 0.08 to 0.1, 3d stage 0.08 to 0.1, 
 4th stage 0.08 to 0.2. 
 
 These clearances are measured by clearance gages, which 
 are tapering slips of steel about l /2-m. wide accurately 
 ground and graduated by markings, the difference in thick- 
 ness of the gage between graduations being 0.001-in., the 
 graduations being %-in. apart. 
 
 When it is desired to measure the clearance, one of the 
 2 inch plugs is taken out, and a clearance gage which has 
 previously been rubbed with red lead is inserted between 
 the revolving and stationary buckets as far as it will go, 
 and then pulled out. 
 
 The red lead marking on the gage will show how far it 
 went in, and the nearest graduation in thousandths of an 
 inch will show the clearance, after noting which, the red 
 lead is rubbed on the gage again, and it is tried on the 
 other side, and if there is any difference either high or low 
 it is corrected by placing the wheel as nearly in the middle 
 of the clearance space as possible, which is done by means 
 of the step supporting screw shown in Fig. 266. 
 
 The clearance may be adjusted while the machine is run- 
 ning at full speed in the following manner : turn the step 
 supporting screw until the wheels are heard or felt to rub 
 slightly, then mark the screw, and turn it in the opposite 
 direction until the wheels rub again. After marking the 
 screw at this point, it should be turned back half way be- 
 tween the two marks. 
 
 This method of adjusting the clearance requires great 
 skill, and experience, and it would seem that the gage 
 method is to be preferred for safety. 
 
58 Steam Engineering 
 
 Packing. The shaft of the Curtis turbine is packed with 
 carbon packing, where it passes through the top head of the 
 wheel case. This packing consists of blocks of carbon made 
 into rings, each ring consisting of three segments which 
 break joints. These rings are fitted to the shaft with a 
 slight clearance, and soon get a smooth polish which is not 
 only frictionless but steam tight. The- rings are held close 
 to the shaft either by light springs, or the pressure of the 
 steam in the case. 
 
 The Baffler. This is a device for restricting the flow of 
 water, or oil to the step and guide bearing. Its most im- 
 portant function is to steady the flow from the pump, and 
 maintain a constant oil film as the pressure varies with the 
 load, and in cases where several machines are operating on 
 the same step-bearing system, the baffler fixes the flow to 
 each machine. The amount, and pressure of oil or water 
 required to float a turbine, and lubricate the guide bearing 
 depend upon each other, and also upon the condition of the 
 step bearing. Usually from 4!/2 to 5 l /o gallons per min- 
 ute flowing under a pressure of from 425 to 450 Ibs. per sq. 
 in. is found to be correct for a 1500 K W machine; of 
 course larger machines require a heavier pressure. The area 
 of the step bearing must be considered also. The principle 
 upon which the baffler operates is as follows : into the barrel 
 or body of the device is inserted a plug which is simply a 
 square threaded worm, the length of which, and the dis- 
 tance it enters the barrel of the baffler determining the 
 amount of flow. The more turns that the water must pass, 
 the less will be the flow. 
 
The De Laval SteamTurbine 
 
 The De Laval steam turbine, the invention of Carl 
 De Laval of Sweden, is noted for the simplicity of its con- 
 struction and the high speed of the wheel 10,000 to 30,000 
 R. P. M. The difficulties attending such high velocities 
 are, however, overcome by the long, flexible shaft and the 
 ball and socket type of bearings, which allow of a slight 
 flexure of the shaft in order that the "wheel may revolve 
 about its center of gravity, rather than the geometrical 
 center or center of position. All high speed parts of the 
 machine are made of forged nickel steel of great tensile 
 strength. But one of the most striking features of this 
 turbine is the diverging nozzle, also the invention of De 
 Laval. 
 
 It is well known that in a correctly designed nozzle the 
 adiabatic expansion of the steam from maximum to mini- 
 mum pressure will convert the entire static energy of the 
 steam into kinetic. Theoretically this is what occurs in 
 the De Laval nozzle. The expanding steam acquires great 
 velocity, and, the energy of the jet of steam issuing from 
 the nozzle is equal to the amount of energy that would be 
 developed if an equal volume of steam were allowed to 
 adiabatically expand behind the piston of a reciprocating 
 engine, a condition, however, which for obvious reasons 
 has never yet been attained in practice with the reciprocat- 
 ing engine. But with the divergent nozzle the conditions 
 are different. 
 
 Referring to Fig. 267, a continuous volume of steam 
 at maximum pressure is entering the nozzle at E, and, pass- 
 
 59 
 
60 
 
 Steam Engineering 
 
 ing through it, expands to minimum pressure at F, the 
 temperature of the nozzle being at the same time constant, 
 and equal to the temperature of the passing steam. The 
 
 FIG. 267 
 DE LAVAL NOZZLE 
 
 principles of the De Laval expanding nozzle are in fact 
 more or less prominent in all steam turbines. The facilities 
 for converting heat into work are increased by its use, and 
 
The De Laval Turbine 61 
 
 the losses by radiation and cooling influences are greatly 
 lessened. 
 
 The De Laval steam turbine is termed by its builders 
 a high-speed rotary steam engine. It has but a single 
 wheel, fitted with vanes or buckets of such curvature as 
 
 FIG. 268 
 THE DE LAVAL TURBINE WHEEL AND NOZZLES 
 
 has been found to be best adapted for receiving the im- 
 pulse of the steam jet. There are no stationary or guide 
 blades, the angular position of the nozzles giving direction 
 to the jet. Fig. 268 shows the form of wheel and the 
 nozzles. The nozzles are placed at an angle of 20 to the 
 
62 Steam Engineering 
 
 -O 
 
 plane of motion of the buckets, and the course of the 
 steam is shown by the illustration. 
 
 The heat energy in the steam is practically devoted to 
 the production of velocity in the expanding or divergent 
 nozzle, and the velocity thus attained by the issuing jet 
 of steam is about 4,000 ft. per second. To attain the 
 maximum of efficiency the buckets attached to the peri- 
 phery of the wheel against which this jet impinges should 
 have a speed of about 1,900 ft. per second, but, owing to 
 the difficulty of producing a material for the wheel strong 
 enough to withstand the strains induced by such a high 
 speed, it. has been found necessary to limit the peripheral 
 speed to 1,200 or 1,300 ft. per second. 
 
 Fig. 269 shows a De Laval steam turbine motor of 300 
 H. P., which is the largest size built up to the present 
 time, its use having been confined chiefly to light work. 
 
 The turbine illustrated in Fig. 269 is shown directly 
 connected to a 200 K. W. two-phase alternator. The 
 steam and exhaust connections are plainly shown, as also 
 the nozzle valves projecting from the turbine casing. The 
 speed of the turbine wheel and shaft is entirely too high 
 for most practical purposes, and it is reduced by a pair of 
 very perfectly cut spiral gears, usually made 10 to 1. 
 These gear wheels are made of solid cast steel, or of cast 
 iron with steel rims pressed on. The teeth in two rows 
 are set at an angle of 90 to each other. This arrange- 
 ment insures smooth running and at the same time checks 
 any tendency of the shaft towards end thrust, thus dis- 
 pensing with a thrust bearing. 
 
 The working parts of the machine are clearly illustrated 
 in Fig. 270, and a fairly good conception of the assembling 
 
The De Laval Turbine 
 
 63 
 
 FIG. 269 
 
 of the various members, and especially the reducing gears, 
 may be had by reference to Fig. 271, which shows a 110 
 
Steam Engineering 
 
 FIG. 270 
 
 H. P. turbine and rotary pump with the upper half of the 
 gear case and field frame removed for purposes of inspec- 
 
The De Laval Turbine 
 
 65 
 
 
 FIG. 271 
 
 tion. The slender shaft is seen projecting from the center 
 of the turbine case, and upon this shaft are shown the 
 
66 Steam Engineering 
 
 small pinions meshing into the large spiral gears upon the 
 two pump shafts. 
 
 Eef erring to Fig. 270, A is the turbine shaft, B is the 
 turbine wheel, and C is the pinion. As the turbine wheel 
 is by far the most important element, it will be taken up 
 first. It is made of forged nickel steel, and it is claimed 
 by the builders, the De Laval Steam Turbine Co., of Tren- 
 ton, New Jersey, that it will withstand more than double 
 the normal speed before showing any signs of distress. A 
 clear idea of the construction of the wheel and buckets 
 may be had by reference to Fig. 268. The number of 
 buckets varies according to the capacity of the machine. 
 There are about 350 buckets on a 300 H. P. wheel. The 
 buckets are drop forged, and made with a bulb shank 
 fitted in slots milled in the rim of the wheel. 
 
 Fig. 272 is a sectional plan of a 30 H. P. turbine con- 
 nected to a single dynamo, and Fig. 273 is a sectional ele- 
 vation of the same. 
 
 The steam, after passing the governor valve C, Fig 273, 
 enters the steam chamber D, Fig. 272, from whence it is 
 distributed to the various nozzles. The number of these 
 nozzles depends upon the size of the machine, ranging 
 from one to fifteen. They are generally fitted with shut- 
 off valves (see Fig. 269) by which one or more nozzles can 
 be cut out when the load is light. This renders it possible 
 to use steam at boiler pressure, no matter how small the 
 volume required for the load. This is a matter of great 
 importance, especially where the load varies considerably, 
 as, for instance, there are plants in which during certain 
 hours of the day a 300 H. P. machine may be taxed to its 
 utmost capacity and during certain other hours the load 
 on the same machine may drop to 50 H. P. In such cases 
 
FIG. 272 
 
68 Steam Engineering 
 
 the number of nozzles in action may be reduced by closing 
 the shut-off valves until the required volume of steam is 
 admitted to the wheel. This adds to the economy of the 
 machine. After passing through the nozzles, the steam, 
 as elsewhere explained, is now completely expanded, and 
 in impinging on the buckets its kinetic energy is trans- 
 ferred to the turbine wheel. Leaving the buckets, the 
 steam now passes into the exhaust chamber G, Fig. 272, 
 and out through the exhaust opening H, Fig. 273, to the 
 condenser or atmosphere as the case may be. 
 
 The gear is mounted and enclosed in the gear case I, 
 Fig. 272. J is the pinion made solid with the flexible 
 shaft and engaging the gear wheel K. This latter is 
 forced upon the shaft L, which, with couplings M, connects 
 to the dynamo, or is extended for other transmission. 
 
 0, Fig. 273, is the governor held with a taper shank in 
 the end of the shaft L, and by means of the bell crank P 
 operates the governor valve C. The flexible shaft is sup- 
 ported in three bearings, Fig. 272. Q and R are the pin- 
 ion bearings and S is the main shaft bearing which carries 
 the greater part of the weight of the wheel. This bearing 
 is self-aligning, being held to its seat by the spring and cap 
 shown. 
 
 T, Fig. 272, is the flexible bearing, being entirely free to 
 oscillate with the shaft. Its only purpose is to prevent 
 the escape of steam when running non-condensing, or the 
 admission of air to the wheel case when running condens- 
 ing. The flexible shaft is made very slender, as will be 
 observed by comparing its size with that of the rotary pump 
 shaft in Fig. 271. It is by means of this slender, flexible 
 shaft that the dangerous feature of the enormously high 
 speed of this turbine is eliminated. 
 
The De Laval Turbine 
 
 69 
 
 FIG. 273 
 
70 Steam Engineering 
 
 The governor is of the centrifugal type, although dif- 
 fering greatly in detail from the ordinary fly ball governor, 
 as will be seen by reference to Fig. 274. It is connected 
 directly to the end of the gear wheel shaft. Two weights 
 B are pivoted on knife edges A with hardened pins C, 
 bearing on the spring seat D. E is the governor body 
 fitted in the end of the gear wheel shaft K and has seats 
 
 FIG. 274 
 
 milled for the knife edges A. It is afterwards reduced in 
 diameter to pass inside of the weights and its outer end is 
 threaded to receive the adjusting nut I, by means of which 
 the tension of the spring, and through this the speed of the 
 turbine, is adjusted. When the speed accelerates, the 
 weights, affected by centrifugal force, tend to spread apart, 
 and pressing on the spring seat at D push the governor 
 
The De Laval Turbine 71 
 
 pin G to the right, thus actuating the bell crank L and cut- 
 ting off a part of the flow of steam. 
 
 It has been found necessary with this turbine, when 
 running condensing, to introduce a valve termed a vacuum 
 valve, also controlled by the governor, as it has been found 
 that the governor valve alone is unable to hold the speed 
 of the machine within the desired limit. The function of 
 the vacuum valve is as follows: The governor pin G act- 
 uates the plunger H, which is screwed into the bell crank 
 L, but without moving the plunger relative to said crank. 
 This is on account of the spring M being stiffer than the 
 spring N, whose function is to keep the governor valve open 
 and the plunger H in contact with the governor pin. When 
 a large portion of the load is suddenly thrown off, the 
 governor opens, pushing the bell crank in the direction of 
 the vacuum valve T. This closes the governor valve, which 
 is entirely shut off when the bell crank is pushed so far that 
 the screw barely touches the vacuum valve stem J. 
 Should this not check the speed sufficiently, the plunger 
 H is pushed forward in the now stationary bell crank, and 
 the vacuum valve is opened, thus allowing the air to rush 
 into the space P in which the turbine wheel revolves, and 
 the speed is immediately checked. 
 
 The main shaft and dynamo bearings are ring oiling. 
 The high-speed bearings on the turbine shaft are fed by 
 gravity from an oil reservoir, and the drip oil is collected 
 in the base and may be filtered and used over again. 
 
 The fact that the steam is used in but a single stage or 
 set of buckets and then allowed to pass into the exhaust 
 chamber might appear at first thought to be a great loss 
 of kinetic energy, but, as has been previously stated, the 
 static energy in the steam as it enters the nozzles is con- 
 
Steam Engineering 
 
 verted into kinetic energy by its passage through the diver- 
 gent nozzles, and the result is a greatly increased volume of 
 steam leaving the nozzles at a tremendous velocity, but at 
 a greatly reduced pressure practically exhaust pressure 
 impinging against the buckets of the turbine wheel and 
 thus causing it to revolve. 
 
 
 \ 
 
 L23 
 
 FIG. 275 
 
 Efficiency tests of the De Laval turbine show a high econ- 
 omy in steam consumption,, as for instance, a test made by 
 Messrs. Dean and Main of Boston, Mass., on a 300 H. P. 
 turbine, using saturated steam at about 200 Ibs. pressure 
 per sq. in. and developing 333 Brake H. P., showed a steam 
 consumption of 15.17 Ibs. per B. H. P., and the same ma- 
 chine, when supplied with superheated steam and carrying 
 
The De Laval Turbine 73 
 
 a load of 352 B. H. P., r-onsumed but 13.94 Ibs. per B. 
 H. P. These results compare most favorably with those of 
 the highest type of reciprocating engines. 
 
 Fig. 275 shows a cross section of a 300 H. P. De Laval 
 wheel, showing the design necessary for withstanding the 
 high centrifugal stress to which these wheels are subjected. 
 All De Laval wheels are tested to withstand the centrifugal 
 stress of twice their normal velocity without showing signs 
 of fatigue. 
 
 A characteristic feature of the De Laval steam turbine is 
 that none of its running parts are subject to the full press- 
 ure of the steam, as the steam is fully expanded in the nozzle 
 before it reaches the turbine wheel. This feature, which 
 will not be found in any other heat motor, is of great value 
 and promising future in the direction of using high press- 
 ures with resultant increase in economy of fuel. The restric- 
 tion as to the steam pressure that can be used is found only 
 with the boiler, and as far as the steam turbine itself is con- 
 cerned, it has been operated successfully with a pressure as 
 high as 3,000 Ibs. per square inch. 
 
Allis-Chalmers Steam Turbine 
 
 Fig. 276 shows a general view of the Allis-Chalmers 
 steam turbine, and although it is essentially of the "Par- 
 sons" type, still there are a number of modifications in 
 details of construction, as compared with the Westinghouse- 
 Parsons steam turbine, some of which, no doubt may be 
 considered as adding to the efficiency, and durability of 
 the machine. 
 
 Fig. 277 is a sectional view of the "elementary" Parsons 
 type of steam turbine, and its various parts are described 
 as follows: 
 
 Main bearings, A and B. Thrust bearing, R. Steam 
 pipe C. Main throttle valve, D, which is balanced, and 
 operated by the governor. Steam enters the cylinder 
 through passage E, passes to the left through the alternate 
 rows of stationary and revolving blades, leaving the cylinder 
 at F and passes into the condenser, or atmosphere through 
 passage G. H, J and K are the three steps or stages of the 
 machine. L, M and N are the three balance pistons. 0, P 
 and Q are the equalizing passages, connecting the balance 
 pistons with the corresponding stages. 
 
 Fig. 278 shows a sectional veiw of the "Parsons" turbine 
 with the Allis-Chalmers modifications. L and M are the 
 two balance pistons at the high pressure end. Z is a smaller 
 balance piston placed in the low pressure end, yet having 
 the same effective area as did the larger piston N shown in 
 Fig. 277. and Q are the two equalizing passages for 
 pistons L and M. Passage P is omitted in this construc- 
 tion, and balance piston Z is equalized with the third stage 
 
 75 
 
FIG. 27(5 
 THE ALLIS-CHALMERS STEAM TURBINE 
 
The AUis-Chatmers Turbine 
 
 77 
 
 pressure at Y. Valve V is a by-pass valve to allow of live 
 steam being admitted to the second stage of the cylinder 
 in case of a sudden overload. This by-pass valve is the 
 equivalent of the by-pass valve used to admit live steam to 
 
 FIG.I 
 
 ELEMENTARY PARSONS TYPE STEAM TURBINE 
 
 FIG. 277 
 
 the low pressure cylinder of a compound reciprocating en- 
 gine. Valve V is arranged to be operated, either by the 
 governor or by hand, as the conditions may require. Fric- 
 
 FIG. 278 
 
 tionless glands made tight by water packing are provided 
 at S and T where the shaft passes out of the cylinder. The 
 shaft is extended at IT and connected to the generator shaft 
 by a flexible coupling. 
 
78 Steam Engineering 
 
 The action of the steam, and the general arrangement of 
 the stationary, and moving blades is practically the same 
 in the two turbines, with the exception that, in the larger 
 sizes of the Allis- Chalmers turbine the "balance" pistons for 
 
 t 
 
 w^WX^S^VT^ 
 
 MOVING 
 BLADES 
 
 STATTONARY 
 BLADES 
 
 MOVING 
 BLADES 
 
 STATIONARY 
 
 BLADES 
 
 MOVING 
 BLADES 
 
 STATIONARY 
 BLADES 
 
 FIG. 279 
 
 Showing Arrangement of Blading and Course of the Steam in 
 Parsons Steam Turbine 
 
 neutralizing the end thrust, are arranged in a different 
 manner, the largest one of the three pistons (piston N 
 Fig. 277) is replaced by a smaller balance piston. 
 
 This piston presents the same effective area for the steam 
 to act upon, as did the larger piston, for the reason that the 
 
The Allis-Chalmers Turbine 79 
 
 working area of the latter in its original location consisted 
 only of the annular area included between its periphery 
 and the periphery of the next smaller piston. The 
 pressure of the steam is brought to bear upon this 
 equalizing piston in its new position, by means of passages 
 or ports through the body of the rotor, connecting the third 
 stage of the cylinder with the supplementary cylinder, in 
 which the piston revolves. Fig. 279 shows the arrangement 
 of blading, the course of the steam being indicated by the 
 arrows. The clearances between the edges of the revolving 
 and stationary blades, as shown in the cut are relatively 
 out of proportion to the actual clearances allowed. 
 
 This clearance is preserved by means of a small thrust- 
 bearing provided inside the housing of the main bearing. 
 
 This thrust-bearing can be adjusted to locate and hold 
 the rotor in such a position as will allow sufficient clear- 
 ance to prevent actual contact between the moving and 
 stationary blades, and yet reduce the leakage of s.team to 
 a minimum. 
 
 The method by which the blades are fitted to and held 
 in the rotor and cylinder of the Allis-Chalmers steam tur- 
 bine is as follows : Each blade is individually formed by 
 special machine tools, so that its root or foot is of an an- 
 gular, or dove-tail shape, and at its tip there is a projection. 
 In order that the roots of the blade may be firml) 7 held in 
 position, a foundation ring, A, Fig. 280, is provided, which 
 after being formed to a circle of the proper diameter, has 
 slots cut in it by a special milling machine. 
 
 These slots are formed of dove-tail shape to receive the 
 roots of the blades, and are at the same time accurately 
 spaced, and inclined so as to give the required pitch and 
 angles to the blades. 
 
80 
 
 Steam Engineering 
 
 The foundation rings are also of dove- tail shape in cross- 
 section, those holding the stationary blades are inserted 
 in dove-tail grooves in the cylinder and those holding the 
 revolving blades being pressed into the rotor or spindle. 
 
 The rings are firmly held in their places by key-pieces 
 driven into place and upset into under-cut grooves, thus 
 positively locking the whole structure together, and making 
 
 FIG. 280 
 
 it practically impossible for a blade to get out of place. 
 
 The tips of the blades are held and firmly bound together 
 by a shroud-ring, B, Fig. 280. 
 
 The shroud-rings are made channel-shape, in cross-sec- 
 tion, the flanges being made thin in order to prevent 
 dangerous heating in case of accidental contact with either 
 the walls of the cylinder or the surface of the rotor. 
 
The Allis-Chalmers Turbine 81 
 
 The bearings of this turbine are of the self-adjusting 
 ball and socket type, designed for high speed. Shims are 
 provided for proper alignment. The lubrication of the 
 four bearings, two for the turbine, and two for the gen- 
 erator, is accomplished by supplying an abundance of oil 
 to the middle of each bearing and allowing it to flow out 
 at the ends where it is caught, passed through a cooler, 
 and pumped back to the bearings. 
 
 The fact that the oil is supplied in large quantities to 
 the bearings does not involve a heavy oil bill. 
 
 The journals are practically floating on films of oil, thus 
 preventing that "wearing out" of the oil that occurs when 
 it is supplied in small "doses." 
 
 The governor is driven from the turbine shaft by means 
 of cut gears working in an oil-bath. 
 
 The governor operates a balance throttle valve by means 
 of a relay, except in very small sizes in which the valve 
 is worked direct. 
 
 In order to provide for any possible accidental derange- 
 ment of the main governing mechanism, an entirely sep- 
 arate safety, or over-speed governor is furnished. This 
 governor is driven directly by the turbine shaft without 
 the intervention of gearing, and is so arranged and adjusted 
 that if the turbine should reach a predetermined speed above 
 that for which the main governor is set, the safety governor 
 will come into action and trip a valve, shutting off the 
 steam and stopping the turbine. A strainer is provided 
 through which the steam is passed before admission to 
 the turbine. 
 
 For connecting the rotors of the turbine and generator 
 a special type of flexible coupling is used to provide for any 
 slight inequality in the wear of the bearings, to permit 
 
82 Steam Engineering 
 
 axial adjustment of the turbine spindle, and to allow for 
 differences in expansion. This coupling is so made that it 
 can be readily disconnected for the removal of the turbine 
 spindle, or of the revolving field of the generator. Provi- 
 sion is made for ample lubrication of the adjoining faces 
 of the coupling. The coupling is enclosed in the bearing 
 housing, so that it is completely protected against damage, 
 and cannot cause injury to the attendants. 
 
 Waste of heat by radiation is prevented in the following 
 manner : 
 
 The hot parts of the turbine, up to the exhaust chamber 
 are covered with an ample thickness of non-conducting 
 material and lagged with planished steel. 
 
 For large Allis-Chalmers turbines the bedplate is di- 
 vided into two parts, one carrying the low-pressure end 
 of the turbine and the bearings of the generator, the other 
 carrying the high-pressure end of the turbine. The tur- 
 bine is secured to the former, while the latter is provided 
 with guides which permit the machine to slide back and 
 forth with differences of expansion caused by varying tem- 
 perature, at the same time maintaining the alignment. 
 
 Fig. 281 shows the spindle, or rotor of the Allis-Chalmers 
 turbine. The rings which carry the blades are pressed on 
 the shaft. Fig. 282 illustrates the blades as they appear 
 when fitted on to the rotor. The shroud ring protecting 
 the tips of the blades is also shown in place. Fig. 283 
 shows another view of the blade construction. This is a 
 half-ring of blades inserted in the foundation ring before 
 being placed upon the rotor. 
 
 Fig. 284 shows several rows of stationary blades as they 
 appear, fitted in the cylinder of an Allis-Chalmers steam 
 turbine. 
 
The AUis-Chalmers Turbine 
 
 FIG. 281 
 ROTOR OF ALLIS-CH A LMERS STEAM TURBINE 
 
84 
 
 Steam Engineering 
 
 FIG. 282 
 
 Starting Up. As a rule in preparing to start a steam 
 [turbine, especially one of the "Parsons," type, the first 
 
The Allis-Chalmers Turbine 85 
 
 move is to open the throttle slightly, to allow as much steam 
 as possible to flow through the turbine without causing il 
 to start. This requires but a few seconds, and about an 
 equal period of time is required to start the auxiliary oil 
 pump. The inlet valve is always left open to the surface 
 condensers, so they are always full of water. The outlet valve 
 is quickly opened a certain number of turns, which is known 
 to be sufficient for all purposes, and this is easily done be- 
 fore the moderate amount of steam flowing through has had 
 time to heat the condenser unduly. By this time the oil 
 is sufficiently high in the reservoir to permit the turbine to 
 be started very slowly, and it doubtless warms up rather 
 more evenly when turning over than when standing. When 
 the oil has reached its normal level in the reservoir, the 
 turbine is given more steam, and the field cut in. 
 
 The principal precautions to be observed are, not to start 
 without properly warming up, also to be certain that the oil 
 is circulating freely through the bearings. 
 
 The vacuum should not be on until the water glands seal, 
 and care should be taken not to run on vacuum without a 
 load on the turbine. 
 
 If a turbine vibrates objectionably when started after a 
 moderate time has been allowed for warming, say 6 minutes 
 for a 500-kilowatt, 10 minutes for a 2000-kilowatt, and 15 
 or,perhaps 20 minutes for larger sizes, it is highly probable 
 that there is something structurally wrong with it, and any 
 longer period will do but little, if any, good ; furthermore, 
 it will be subject to mysterious "spells" or "fits" of vibra- 
 tion upon changes of load or vacuum. 
 
 In Operation. The throttle, and inlet gages should be 
 closely watched, to see that neither the pressure, nor the 
 steam temperature varies much. The vacuum should also 
 
Steam Engineering 
 
 FIG. 283 
 
The Allis-Chalmers Turbine 
 
 87 
 
 be kept constant, as well as the water glands, and those 
 pressures indicated by the oil gages. The temperature of 
 the oil flowing to and from the bearings should not exceed 
 135 Fahr. . 
 
 FIG. 284 
 
 Shows a Number of Rows of Stationary Blades Fitted in the 
 Cylinder of an Allis-Chalmers Steam Turbine 
 
 The governor parts also should be oiled at regluar 
 intervals. 
 
 Stopping the turbine is practically the reverse of start- 
 ing, the successive steps being as follows : starting the aux- 
 
88 Steam Engineering 
 
 iliary oil pump, freeing it of water and allowing it to run 
 slowly ; removing the load gradually ; breaking the vacuum 
 when the load is almost zero, shutting off the condenser 
 injection and taking care that the steam exhausts freely 
 into the atmosphere ; shutting off the gland water when the 
 load and vacuum are off; pulling the automatic stop to 
 trip the valve and shut off steam and, as the speed of the 
 turbine decreases, speeding up the auxiliary oil pump to 
 maintain pressure on the bearings; then, when the turbine 
 has stopped, shutting down the auxiliary oil pump, turning 
 off the cooling water, opening the steam chest drains and 
 slightly oiling the oil inlet valve-stem. During these 
 operations the chief particulars to be heeded are: not to 
 shut off the steam before starting the auxiliary oil pump 
 nor before the vacuum is broken, and not to shut off the 
 gland water with vacuum on the turbine. The automatic 
 stop should also remain unhooked until the turbine is about 
 to be started up again. 
 
 General Suggestions. Water used in the glands of the 
 turbine must be free from scale-forming impurities, and 
 should be delivered at the turbine under a steady pressure 
 of not less than 15 pounds. The pressure in the glands 
 will vary from 4 to 10 pounds. This water may be warm. 
 In the use of water for the cooling coils and of oil for the 
 lubricating system, nothing more is required than ordinary 
 good sense dictates. An absolutely pure mineral oil must 
 be supplied, of a nonfoaming charcter, and it should be 
 kept free through filtering from any impurities. 
 
 These suggestions apply more particularly to steam tur- 
 bines of the "Parsons" type, exhausting into condensers. 
 For turbines built to be run non-condensing the portion 
 relating to vacuum does not of course apply. 
 
Hamilton-Holzwarth Steam Turbine 
 
 In order to thoroughly understand the underlying prin- 
 ciples of the steam turbine, and the action of the steam 
 within it, one must get definitely fixed in his mind this 
 fact, viz., that there is no similarity between it and the 
 reciprocating engine, and the action of the steam upon the 
 piston in driving it back and forth. In fact, there is more 
 similarity between the reciprocating engine and the rotary 
 engine than there is in the case of the turbine. In the 
 rotary engine the steam pushes a piston in the same manner 
 as it does in the reciprocating engine, with the exception 
 that the piston of the rotary engine travels entirely around 
 the shaft, while the piston of the reciprocating engine 
 travels back and forth in a straight line motion. It will 
 be much easier to get a clear idea of the action of the tur- 
 bine if one will for the time being drop all knowledge he 
 may have of reciprocating and rotary engines. He will 
 then be able to more readily grasp, and better understand 
 the action of the steam turbine. 
 
 One of the most comprehensive, and at the time most 
 simple explanations of the action of the steam upon the 
 blades of the turbine, and also upon the piston of the 
 reciprocating engine, in both of 'which cases rotary motion 
 is produced, but in two different ways, is given by Hans 
 Holzwarth. He says : "Take a large wheel which is 
 fastened to a vertical shaft. Grasp this wheel at the rim 
 at a certain point, and walk continuously around the shaft, 
 always retaining the hold, like a horse walking around 
 a capstan fastened to a bar or pole which he pulls after him. 
 
 89 
 
90 Steam Engineering 
 
 Or stand still in a certain spot and take the wheel hy the 
 rim and cause it to revolve (like opening and closing a 
 valve by hand), by changing hands so that the whole rim 
 is constantly revolving." 
 
 The first illustration clearly explains the manner in 
 which the shaft of the reciprocating engine is caused to 
 revolve, by means of the static expansion force of the steam 
 acting upon the crank pin, through the medium of 
 the piston, piston rod, cross head, and connecting 
 rod. In the second illustration, in which the man 
 turns the wheel by simply standing still in one place, and 
 causing the wheel to revolve by grasping the rim and giv- 
 ing it a push, first with one hand, and then with the other, 
 we have a simple explanation of how the steam causes the 
 shaft of the turbine to revolve, by a constant series of 
 pushes, or impulses against the movable blades that are key 
 seated to the drum, which in turn is keyed to the shaft, 
 the moving blades representing the rim of our wheel. 
 
 Every one knows that in order to be able to turn the 
 aforesaid wheel the man must have a good floor to stand 
 upon, and he must also have a good foothold on the floor, 
 because he exerts the same amount of pressure on the 
 floor, that he exerts against the rim of the wheel. This 
 explains why there must be stationary blades, as well as 
 revolving blades in a turbine. 
 
 The actual pressure exerted upon any single blade in a 
 turbine is in reality very light. Take, for example, a 300 
 K. W. Westinghouse turbine. There are altogether in a 
 machine of this size 31,073 blades, of which 16,095 are mov- 
 ing blades. The pressure that each blade exerts in turning 
 the shaft is a little over one ounce, but owing to the large 
 number of blades, and the velocity of the steam, the power 
 is developed. 
 
Hamilton-Hohwarth Turbine 
 
 91 
 
 
 FIG. 285 
 HAMILTON-HOLZWARTH STEAM TURBINE 
 
 The Hamilton-Holzwarth steam turbine resembles in 
 many respects the Westinghouse-Parsons turbine, prominent 
 
92 Steam Engineering 
 
 of which is that it is a full stroke turbine ; that is, the steam 
 flows through it in one continuous belt, or veil in a screw 
 line, the general direction being parallel with the shaft. 
 But unlike the Parsons type, the steam in the Hamilton- 
 Holzwarth turbine is made to do its work only by impulse, 
 and not by impulse and reaction combined. The smaller 
 sizes are built in a single casing or cylinder, but for units 
 of 750 K. W. and larger there are two parts, viz., high 
 and low pressure, thus resmbling in some respects a com- 
 pound reciprocating engine. 
 
 The Hamilton-Holzwarth steam turbine is based upon 
 and has been developed from the designs of Prof. Eateau, 
 of Paris, and is being manufactured in this country by 
 the Hooven-Owens-Rentschler Co., of Hamilton, Ohio. It 
 is horizontal, and placed upon a rigid bed plate of the box 
 pattern. All steam, oil and water pipes are within and 
 beneath this bed plate, as are also the steam inlet valve and 
 the regulating and by-pass valves. 
 
 There are no balancing pistons in this machine, the 
 axial thrust of the shaft being taken up by a thrust ball- 
 bearing. The interior of the cylinder is divided into a 
 series of stages by stationary discs which are set in grooves 
 in the cylinder, and are bored in the center to allow the 
 shaft, or rather the hubs of the running wheels that are 
 keyed to the shaft, to revolve in this bore. 
 
 Clearance. The clearance allowed is as small as prac- 
 ticable, as it is in this clearance between the revolving hub 
 and the circumference of the bore of the stationary disc 
 that the leakage losses occur. It should be noted that be- 
 tween each two stationary discs there is located a running 
 wheel, and that the clearance between the running vanes 
 and the stationary vanes is made as slight as is consistent 
 
Hamilton-Holzwartli Turbine 93 
 
 with safe practice ; otherwise leakage would occur here 
 also, and besides this there would be a distortion of the 
 steam jet and entrainment of the surrounding atmosphere, 
 resulting in a rapid decline in economy if the clearance 
 between the stationary and moving elements was not re- 
 duced to as small a fraction as possible. 
 
 As before stated, the stationary discs are firmly secured 
 to the interior walls of the casing. At intervals on the 
 outside periphery of these discs are located the stationary, 
 or guide vanes. These are made of drop forged steel. They 
 are set in -a groove on the outside edge of the disc and 
 fastened with rivets. Both disc and vanes are then ground, 
 giving the vanes the profile that they should have for the 
 most efficient expansion of the steam. After this is done 
 a steel ring is shrunk on the outside periphery of the vanes 
 and the steam channels in the disc. These discs are then 
 placed in the grooves in the casing at regular intervals, 
 and in the spaces between them are the running wheels. 
 
 The casing is divided into an upper and lower half. The 
 running wheels are built with a cast steel hub having a 
 steel disc riveted on to each side, thus forming a circum- 
 ferential ring space into which the running vanes are 
 riveted. A thin steel band or rim is tied on the outer edge 
 of the vanes, thus forming an outer wall to the steam 
 channels and confining the steam within the vanes. These 
 vanes are also milled on both edges, on the influx, and 
 efflux side of the wheel, thus forming them to the shape 
 corresponding to the theoretical diagram. 
 
 Tn all steam turbines one of the main requisites for a 
 quiet-running machine is that the revolving element or 
 rotor shall be perfectly balanced. The rotary body of the 
 Hamilton-Holzwarth turbine consists of a plurality of run- 
 
94 Steam Engineering 
 
 ning wheels, each one of which is balanced by itself before 
 being placed upon the shaft. All the bearings are lubri- 
 cated in a thorough manner by oil forced up into the bot- 
 tom bushing or shell under slight pressure. Flexible coup- 
 lings are used between the high and low-pressure shafts, 
 and for connecting the turbine shaft to the generator shaft 
 or other shaft to be driven. By means of the thrust ball- 
 bearing on the exhaust end of the turbine the shaft may 
 be adjusted in an axial direction in such a manner as to 
 accurately preserve the desired position of the running 
 wheels. 
 
 Fig. 285 shows a general view of the Hamilton-Holz- 
 warth turbine, and the action of the steam within the ma- 
 chine may be described as follows: After leaving the 
 steam separator that is located beneath the bed plate, the 
 steam passes through the inlet or throttle valve, the stem 
 of which extends up through the floor near the high- 
 pressure casing and is protected by a floor stand and 
 equipped with a hand wheel, shown in Fig. 285. The 
 steam now passes through the regulating valve. From this 
 valve it is led through a curved pipe to the front head of 
 the high pressure casing or cylinder. In this head is a 
 ring channel into which the steam enters, and from which 
 it flows through the first set of stationary vanes. In these 
 vanes the first stage of expansion occurs. 
 
 Construction of the Stationary Blade. A stationary 
 blade is constructed in the following manner : A circular 
 cast-iron disc a, Fig. 286, has a bore b corresponding to 
 the diameter of the shaft, with the necessary clearance. 
 On the outer circumference of this disc there is cut a 
 groove c. The stationary guides, consisting of a vane of 
 proper curvature and the adjoining piece, are of drop- 
 
Hamilton-Hohwarth Turbine 
 
 95 
 
 forged steel, milled on all sides of the adjoining piece which 
 fits into the circular groove c. These vanes are arranged 
 all around the circumference so that one adjoining piece 
 touches another and they are held in place and fastened 
 securely, by rivets e, to the disk. The outer circumference 
 of these vanes is turned off to the right size, and then a. 
 steel ring f is shrunk over them. This shrunk ring pro- 
 jects into the grooves of the housing. 
 
 Fio. 286 
 
 The Running Wheel. While in the stationary blade the 
 weight is not of great importance, in the running wheel it 
 is very essential to reduce the weight as much as possible. 
 It will be readily understood that the lighter the running 
 wheels are, the less the bearings will have to support, and 
 therefore the shorter they may be constructed, and the 
 better they will work. Furthermore, by keeping down the 
 weight of the running wheel the shaft diameter is kept 
 within small limits. This determines the bore of the sta- 
 tionary blade, and with that the circular space between the 
 bore of the stationary blade and the shaft can be kept 
 
96 
 
 Steam, Engineering 
 
 within small limits; therefore in the construction of this 
 running wheel every dead and unnecessary weight is 
 avoided. 
 
 The running wheel is made up as follows : A steel hub 
 or spider a, Fig. 287, has a bore b fitting closely to the 
 shaft diameter. On both side of the hub are riveted steel 
 discs c. The groove on the outer circumference of the 
 steel disc is turned out and forms a receptacle for the 
 running vanes. The running vane itself consists of the 
 
 FIG. 287 
 
 properly curved blade, with an adjoining piece made in one 
 section of drop-forged steel. The adjoining piece is fin- 
 ished and fits closely into the grooves of the steel disc. The 
 running vanes are held in place and rigidly connected to 
 the steel discs by rivets d, so that the centrifugal force of 
 each vane is taken up by a rivet and transmitted through 
 the rivet to the steel disc. The outer edge f of the vane is 
 turned off and thus provided with an annular groove form- 
 ing a receptacle for the steel band .g, which is tied all 
 around the wheel. It is held in place and secured to the 
 
Hamilton-Hohwarth Turbine 97 
 
 vanes by riveting over the projecting ends of the vanes. 
 The ends of the band are brazed together. 
 
 Beference to Fig. 288, which is a vertical section of this 
 turbine, will serve to make more clear the action of the 
 steam within the machine. The turbine casing a, is made 
 of cast iron of cylindrical shape, and split in the horizontal 
 axis, into the upper half, a, and the lower half, b. In the 
 horizontal points the two halves are bolted together steam 
 tight. The lower half, b, is cast together with the pedestal, 
 c, which is the support for the low pressure bearing, d, and 
 the groove, e, for the stuffing box, f. The outlet opening, 
 g, is arranged in the lower half, b. This lower half is sup- 
 ported on pads of the bed plate, h, with two feet extending 
 on the sides, and fastened thereto. The front head, i, is 
 bolted steam tight to the flange, k, on the front side of 
 the casing. In front of the head, i, is located the regu- 
 lating mechanism pedestal, 1, which combines the high 
 pressure bearing with the housing for regulating mechan- 
 ism, n, and housing, o, for the governor, p. A live steam 
 pipe, g', is connected to an inlet valve, r, and this to a main 
 regulating valve, s, to the inlet flange of the front head, i. 
 The passage of the steam into this front or high pressure 
 head has already been referred to. In the grooves cut in 
 the housing are the stationary blades, t, and in the space 
 between the two following stationary blades is the running 
 wheel, u. All running wheels fit on the shaft, v, and are 
 keyed to the shaft. The shaft, v, is supported in the high 
 pressure bearing, m, on one end, and in the low pressure 
 bearing, d, on the other end. The low pressure bearing 
 has an arrangement which allows the adjustment of the 
 shaft, v, lengthwise in the direction of the turbine. On 
 the outer end of the shaft is the coupling, w, keyed to the 
 
98 
 
 Steam Engineering 
 
 FIG. 288 
 
 HAMILTON-HOLZWARTH STEAM TURBINE 
 Sectional Elevation 
 
Ham iHoft-Holzwarth Turbine 
 
 99 
 
 shaft. This coupling allows connection to be made to 
 the generator, pump, or blower, which is to be driven by 
 the turbine. 
 
 The flow of. the steam from the inlet valve, r, to the 
 exhaust outlet, g, and the manner of the working of the 
 steam in the turbine is as follows: The steam passing 
 through the main regulating valve, s, enters the circular 
 channel of the front head, i, and from here it flows through 
 a circular slot to the first stationary blade, t. Opposite this 
 circular slot is arranged a multitude of vanes, x, Fig. 289, 
 
 1 
 
 
 
 
 3 
 J j 
 
 J 
 
 * 
 
 
 M 
 
 * 
 
 M 
 & 
 
 
 I 
 
 
 ^ 
 
 
 * 
 
 \ 
 
 pq 
 M 
 
 ^ 
 
 I 
 
 ** 
 A 
 s, 
 
 
 
 M 
 
 
 fl 
 
 m 
 
 I 
 
 J 
 / 
 
 ft*, 
 
 * 
 
 
 3 
 
 
 
 
 
 FIG. 2S9 
 
 which give the steam the right expansion in the right 
 direction. With this velocity attained in the stationary 
 blades, the steam impinges upon the vanes, u, of the first 
 running wheel, and the bore of the housing can be kept 
 within larger limits, because the steam flowing through 
 the vanes is prevented from flowing rapidly outward by 
 means of a band secured around the outer circumference 
 of the running wheel. 
 
 The running vanes conform in section somewhat to the 
 Parsons type, but the action of the steam upon them, and 
 
100 Steam Engineering 
 
 also within the stationary vanes is different. The expan- 
 sion of the steam, and consequent development of velocity 
 takes place entirely within the stationary vanes, which also 
 change the direction of flow of the steam, and distribute 
 it in the proper manner to the vanes of the running wheels, 
 which, according to the claims of the makers, the steam 
 enters and leaves at the same pressure, thus allowing the 
 wheel to revolve in a uniform pressure. 
 
 In the low-pressure casing, which is larger in diameter 
 than the high-pressure, the steam is distributed in the 
 same manner as it is in the high-pressure casing. There 
 is, however, in the front head of the low-pressure casing 
 an additional nozzle through which live steam may be ad- 
 mitted in case of overload. The design of this nozzle is 
 such that the live steam entering and passing through it, 
 and controlled by the governor exerts no back pressure on 
 the steam coming from the receiver, but, on the contrary, 
 its action is similar to the action of an injector, that is, it 
 tends to suck the low-pressure steam through the first set 
 of stationary vanes of the low-pressure turbin'e. 
 
 The first stationary disc of the low-pressure turbine has 
 guide vanes all around its circumference, so that the steam 
 enters the turbine in a full cylindrical belt, interrupted only 
 by the guide vanes. To provide for the increasing volume 
 as the steam expands in its course through the turbine, the 
 areas of the passages through the distributers and running 
 vanes must be progressively enlarged. The gradual in- 
 crease in the dimensions of the stationary vanes permits 
 the steam to expand within them, thus tending to maintain 
 its velocity, while at the same time the vanes guide the 
 steam under such a small angle that the force with which 
 it impinges the vanes of the next running wheel is as 
 
Hamilton-Holzwarth Turbine 101 
 
 effective as possible. The curvature of the vanes is such 
 that the steam while passing through them will increase its 
 velocity in a ratio corresponding to its action. 
 
 The purpose of the stationary discs is, as has been stated, 
 to distribute the steam to the running wheel. They also 
 take the back pressure of the steam as it impinges the 
 vanes of the running wheels, thus in a sense acting as 
 balancing pistons. 
 
 The governor is of the spring and weight type, adapted 
 to high speed, and is designed especially for turbine govern- 
 ing. It is directly driven by the turbine shaft, revolving 
 with the same angular velocity. Its action is as follows: 
 Two discs keyed to the shaft drive, by means of rollers, 
 two weights sliding along a cross bar placed at right angles 
 through the shaft and compressing two springs against 
 two nuts on the cross bar. Every movement of the weights, 
 caused by increasing or decreasing the angular velocity of 
 the turbine shaft, is translated by means of levers to a 
 sleeve which actuates the regulating mechanism. These 
 levers are balanced so that no back pressure is exerted upon 
 the weights. The whole governor is closed in by the discs, 
 one on each side, and a steel ring secured by concentric 
 recesses to the discs. In order to decrease the friction 
 within the governor and regulating mechanism, thrust 
 ball-bearings and frictionless roller-bearings are used. 
 
 As previously stated, the regulating valve is located be- 
 neath the bed plate. One side of it is connected by a curved 
 pipe with the front head of the high-pressure cylinder, and 
 the other side is connected with the inlet valve. The regu- 
 lating valve is of the double-seated poppet valve type. 
 Valves and valve seats are made of tough cast steel, to 
 avoid corrosion as much as possible, and the valve body is 
 made of cast iron. 
 
102 Steam Engineering 
 
 Immediately below the regulating valve and forming a 
 part of it in one steam chamber is located the by-pass regu- 
 lating valve. Thus the use of a second stuffing box for 
 the stem of this valve is avoided. The function of this 
 valve is to control the volume of the live steam supply that 
 flows directly to the by-pass nozzles in the front head of 
 the low-pressure casing. This valve is also a double-seated 
 poppet valve. 
 
 The main regulating valve is not actuated directly by 
 the governor, but by means of the regulating mechanism. 
 The construction and operation of this regulating mechan- 
 ism is as follows: The stem of the regulating valve is 
 driven by means of bevel gears by a shaft that is supported 
 in frictionless roller-bearings. 
 
 On this shaft there is a friction wheel that the governor 
 can slide across the face of a continuously revolving fric- 
 tion disc by means of its sleeve and bell crank lever. This 
 revolving disc is keyed to a solid shaft which is driven by 
 a coupling from a hollow shaft. This hollow shaft is driven 
 by the turbine shaft through the medium of a worm gear. 
 The solid shaft, with the continuously revolving friction 
 disc, can be slightly shifted by the governor sleeve so that 
 the two friction discs come into contact when the sleeve 
 moves, that is, when the angular velocity changes. If this 
 change is relatively great, the sleeve will draw the periodi- 
 cally revolving friction disc far from the center of the 
 always revolving one, and this disc will quickly drive the 
 stem of the regulating valve and the flow of steam will thus 
 be regulated. As soon as the angular velocity falls below 
 a certain percentage of the normal speed, the driving fric- 
 tion disc is drawn back by the governor, the regulating 
 valve remains open and the whole regulating mechanism 
 rests or stops, although the shaft is still running. 
 
Hamilton-Holzwarth Turbine 103 
 
 Should the angular velocity of the shaft reach a point 
 2.5 per cent higher than normal, the governor will shut 
 down the turbine. If an accident should happen to the 
 governor, due to imperfect material or breaking or weaken- 
 ing of the springs, the result would be a shut-down of the 
 turbine. 
 
 In order to change the speed of the turbine while run- 
 ning, which might be necessary in order to run the machine 
 parallel with another prime mover, a spring balance is 
 provided, attached to the bell crank lever of the regulating 
 mechanism. The hand wheel of this spring balance is 
 outside of the pedestal for regulating mechanism and near 
 the floor-stand and hand wheel. With this spring balance 
 the speed of the turbine may be changed 5 per cent either 
 way from normal. 
 
 All the bearings of the turbine are thoroughly lubricated 
 with oil forced under pressure by the oil pump driven by 
 means of worm gearing by the turbine itself. After flowing 
 through the bearings the oil is passed through a filter, and 
 from thence to the oil tank located within the bed plate, 
 from whence it is taken by the oil pump. All revolving 
 parts are enclosed, and the principal part of the regulating 
 mechanism operates in a bath of oil. 
 
 The Stuffing-Box. An effective means of packing a 
 swiftly revolving shaft is a long sleeve surrounding the 
 shaft with a very small radial clearance. The reason for 
 this will be found in the throttling action of the steam par- 
 ticles revolving with the shaft. These steam particles have 
 a tendency to fly outwardly and so prevent the steam from 
 passing axially through the small clearance between the 
 shaft and the sleeve. The reader will readily understand 
 that it would not be practical to use such a long sleeve in 
 
104 
 
 Steam Engineering 
 
 the construction of a steam turbine, as this arrangement 
 would considerably increase the length of the free shaft. 
 For the reason that the deflection of the shaft depends 
 upon the third power of the free length of the shaft, it is 
 absolutely necessary to restrict this free length as much as 
 possible. 
 
 FIG. 290 
 
 In the Hamilton-Holzwarth turbine, use is made of the 
 telescopic idea; that is the entire length of the sleeve is 
 split into several parts, and these single parts are shifted 
 together. In Fig. 290 the ring A screwed upon the shaft 
 projects axially into a groove of the ring B, and revolves 
 within it. The ring B does not move at all, but is held in 
 place, and pressed tightly against the turbine casing by 
 means of the ring C which presses against the bushing of 
 
Hamilton-IIohivarth Turbine 105 
 
 the bearing. By screwing the ring C on the ring B. both 
 rings are forced axially in opposite directions. From the 
 casing S the steam seeking to escape, flows axially to T. 
 From there it flows back to U, and then forward to V, 
 being very much throttled in the process. The ring B has 
 an annular groove which must be packed with soft packing. 
 Any accumulating water is collected in the chamber W, in 
 the bushing of the bearing, from whence it is properly 
 drained. The ring E serves only the purpose of tightening 
 the threads between rings C and B. 
 
The Rateau Steam Turbine 
 
 The Bateau turbine is purely an impulse turbine, using 
 wheels of thin plates pressed into a slightly conical form. 
 These are mounted on a common shaft, and separated from 
 each other by division walls. The first wheels have partial 
 peripheral admission, so that the peripheral velocity may be 
 high from the very beginning without using too short 
 blades. The guide blades are set into division walls, and 
 the rotating blades are bent from a single piece of bronze, 
 or steel plate, and are riveted to the double turned rim of 
 the wheel-disc. The shaft bearings were originally built 
 as part of the cover of the turbine, but now are made inde- 
 pendent. At the low pressure end the shaft is made steam 
 tight by means of a simple stuffing box, into which suffi- 
 cient water is allowed to flow to secure steam tightness. 
 As the same pressure exists on both sides of each rotating 
 wheel, the axial thrust has only the small value due to the 
 pressure on the area of the end of the front journal. 
 
 Fig. 291 shows a sectional view of the machine, in which 
 it is to be noted that the wheel discs are riveted to their 
 hubs. 
 
 Fig. 292 shows a view of the turbine with generator, and 
 oil equipment. The construction of the wheels, and division 
 walls can easily be seen in Figs. 293, 294 and 295. The 
 construction according to the latter figure, with division 
 walls made in sections is preferred, because after taking 
 away the casing cover, all the interior parts are easily 
 accessible. 
 
 107 
 
108 
 
 Steam Engineering 
 
 FIG. 291 
 
 The most recent Bateau turbine is of the action type, 
 that is to say, expansion of the steam is fully carried out in 
 
The Bateau Turbine 
 
 109 
 
 u 
 
 
 FIG. 292 
 
 the distributor for each group consisting of a distributor 
 and one moving wheel. The steam therefore acts by its 
 
no 
 
 Steam En gin eering 
 
 velocity and not by its pressure. These turbines are more- 
 over multicellular, that is to say., they consist of a certain 
 number of elements, each element comprising one dis- 
 tributor and one moving wheel. 
 
 This turbine has been developed by the firm of Sautter- 
 
 FIG. 293 
 
 Hartle, of Paris, France, from designs by Prof. A. Rateau, 
 who is also the inventor of the Eateau steam regenerator, 
 through which the exhaust from non-condensing recipro- 
 cating engines may be passed to a low-pressure turbine, 
 thus resulting in the development of power from steam 
 which otherwise would be wasted. A very complete and 
 
The Rateau Turbine 
 
 111 
 
 successful installation of this character has been in opera- 
 tion for some time at the extensive steel works of the Inter- 
 national Harvester Company at Chicago, 111., and judging 
 from the results of an exhaustive series of tests conducted 
 by Mr. F. G. Gaesch, and published in the June, 1907, 
 issue of. "Power," the system possesses considerable merit. 
 The following description of the installation at the Har- 
 vester Company's plant, is supplied by courtesy of the 
 Western Electric Co., of Chicago. 
 
 FIG. 294 
 
 The Steam Regenerator, or accumulator, consists of a 
 cylindrical wrought-steel shell % of an inch in thickness, 
 11 feet 6 inches in diameter, and 30 feet long, having a 
 central horizontal diaphragm which divides the regenerator 
 into twQ similar compartments. In each compartment 
 there are six elliptical tubes or steam-distributing conduits, 
 A, Fig. 296, which extend from end to end in pairs, and 
 are so placed as to leave spaces, B, between them. (The 
 
112 Steam Engineering 
 
 sectional view is from another installation and only shows 
 four tubes.) Baffle plates, C, are arranged above the space 
 between each pair of tubes. The spaces surrounding the 
 conduits, and, under certain conditions, even the conduits 
 themselves, are filled with water to the extent that the top 
 of the latter is usually submerged three or four inches. 
 The sides of the conduits are perforated with a great many 
 %-inch holes to allow of the lateral escape of steam through 
 
 FIG. 295 
 
 the water, with, occasionally, a further escape from the 
 bottom openings. A large baffle plate in the upper steam 
 space serves for a perfect separation of entrained moisture 
 from the steam. The steam enters by the pipe shown at the 
 left hand of the side elevation, passes to the interior of the 
 elliptical tubes, and escapes into the spaces through the 
 perforations. The circulation of the water takes place in 
 the direction of the arrows; the baffle plates placed above 
 each pair of tubes prevent the water from being thrown 
 
The Rateau Turbine 113 
 
 into the steam space. This flow of steam gives an extreme 
 degree of steam saturation to the water; and the slight 
 back pressure which at first might be expected, owing to the 
 head of water above the rows of perforations, is thereby 
 reduced to insignificant proportions. 
 
 When the supply of steam from main engine ceases, the 
 water liberates part of the heat it has absorbed, and an even 
 flow of low-pressure steam is given off, while the steady 
 demand of the turbine reduces the pressure in the accumu- 
 lator, causing the steam still retained in the tubes to escape, 
 maintaining the circulation of the water, and facilitating 
 the liberation of the steam. Experience has shown that the 
 whole of the contained water participates in the regenera- 
 tive action. The steam is taken from the top of the ac- 
 cumulator to the turbine, and the pressure can be regu- 
 lated by the relief valve shown. The water level is main- 
 tained constant by a ball float contained in a small tank 
 arranged at the back of the regenerator. Generally there is 
 a slight overflow at all times, representing among other 
 things the "make up" from the exhaust steam supply. The 
 regenerator at this plant has a capacity of 55 tons of water, 
 sufficient by actual test to deliver all the steam for a 50 
 per cent overload on the turbine for a period of 430 
 seconds. At full load this would correspond to a period 
 of 390 seconds. The regenerator or accumulator is fitted 
 with the following accessories: First, an adjustible relief 
 valve, which regulates the limits of pressure in the accumu- 
 lator, and allows the steam to escape when the turbine is 
 stopped, or working on a light load; it also prevents back 
 pressure in the cylinders of the reciprocating engine. 
 
 This valve may be connected to the condenser so that in 
 case the turbine is shut down for a period, the main engines 
 may have the benefit of the vacuum. 
 
114 
 
 Steam Engineering 
 
 FIG. 296 
 PLAN AND ELEVATION OF LOW-PRESSURE TURBINE INSTALLATION, 
 
 WITH TRANSVERSE AND LONGITUDINAL SECTIONS OF 
 REGENERATOR 
 
 Second, a non-return water valve, necessary with water 
 accumulators, to prevent any possibility of reflux of water 
 toward the main engines during periods of stoppage. 
 
The Rateau Turbine 115 
 
 Third, automatic level regulators, and gauge glasses, and 
 automatic drains. 
 
 Fourth, piping beginning at the inlet of the receiving 
 drum, including the steam header and mains from the 
 regenerator to the turbine, the exhaust piping from the 
 turbine, and condenser, and the piping between the con- 
 denser and air pump. 
 
 Fifth, a vertical receiving drum 9 feet in diameter, and 
 22 feet long, with baffle plates, and separating chambers, 
 the function of which is to allow the ready escape of steam 
 from the main engines without increase of back pressure 
 on the system. The expansions allowed in this drum con- 
 duce to a more even flow of steam in the steam regenerator. 
 
 Sixth, a 30-inch barometric condenser of the Alberger 
 type, complete with air cooler, exhaust entrainer, expan- 
 sion joint, and an air pump 8x6x12 inches. 
 
 The exhaust steam from a 42x60 Mclntosh & Hemphill, 
 rolling mill engine, passes through the regenerator and into 
 a Eateau low-pressure turbine, to the shaft of which is 
 connected two direct current generators, each of 250 K. W. 
 capacity, at 250 volts, and designed so that they may be 
 operated in parallel. The bearings are of the ring oiled 
 reservoir type, with water jackets. The plant is designed 
 with a view of adding another similar unit, but the evidence 
 of the tests shows that a 750 K. W. unit can be operated 
 with the steam that is available, without allowance for the 
 steam (about 6,000 Ibs. per hour) that is available from 
 auxilliary machinery. 
 
 Part of these auxiliaries already exhaust into an open 
 feed water heater, but the steam regenerator, constituting 
 a perfect feed heating device, can more appropriately re- 
 ceive all the steam from the auxiliaries, with the advantage 
 of some addition to the capacity of the turbine equipment. 
 
11G 
 
 Steam Engineering 
 
 Fig. 297 shows a view of the regenerator and attached 
 equipment. 
 
 The leading objects of the tests made by Mr. Gaesch were, 
 first to determine the steam consumption of the turbine 
 
 ft 
 
 FIG. 297 
 BATEAU REGENERATOR, AND ATTACHED CONDENSER 
 
 per unit of power, and second, to measure the actual 
 amount of steam available for the use of the turbine as 
 delivered from the main engine. 
 
The Bateau Turbine 117 
 
 Space prohibits a detailed description of the method of 
 conducting the tests, and the results derived therefrom. 
 
 The average brake horse power developed by the turbine 
 according to the report of one of the tests was 544 with a 
 steam consumption per B. H. P. per hour of 37 Ibs. The 
 average steam pressure at the turbine was 16.6 Ibs. absolute. 
 The average I. H. P. of the main engine during the same 
 test was 820., with a steam consumption of 61.2 Ibs. per 
 I. H. P. per hour. The total weight of steam available 
 per hour from regenerator to turbine was 56,100 Ibs. 
 
 The main engine, the dimensions of which have already 
 been given, was a reversing rolling mill engine. The stuff- 
 ing box used in the Rateau turbine is clearly illustrated in 
 Figs. 240 to 243. 
 
The Reidler-Stumpf Steam Turbine 
 
 This turbine is manufactured in Germany and its essen- 
 tial characteristics are the peculiarly formed, parallel re- 
 turn buckets derived from the Pelton water wheel, also the 
 rectangular nozzles that allow a homogeneous jet of steam 
 to be directed against the wheel. Fig. 298 shows a view 
 
 FIG. 298 
 
 of one of the wheels, and Fig. 299 shows sections of a 
 bucket, and nozzle. 
 
 The buckets are worked out of a solid forged wheel with 
 a milling cutter, consequently they are very strong, and 
 durable. 
 
 119 
 
120 
 
 Steam Engineering 
 
 The steam jet enters the bucket C from the nozzle B, and 
 is deflected through an angle of 180 degrees, the direction 
 
 FIG. 299 
 
 of its exit being parallel to that of its entrance, as shown 
 by the arrows (Fig. 299). 
 
The Reidler- Stump f Steam Turbine 
 
 121 
 
 This type of wheel has but a one-sided discharge Fig. 
 300 shows another type of this turbine, in which the sta- 
 
 FIG. 300 
 
 tionary buckets D, of the reverse guide are opposed to the 
 rotating buckets C of the wheel in such a manner as to 
 form a continuous closed cylinder in wjuch the steam in 
 
122 Steam Engineering 
 
 its course through the wheel continually whirls or spirals 
 around and around. With this type of turbine the steam 
 enters the bucket wheel from the nozzle as shown in Fig. 
 299, but instead of escaping after it has passed once 
 through the bucket, it is caught by the guide or stationary 
 bucket and returned to the wheel, this process being re- 
 peated again and again until practically all of the energy 
 in the steam has been abstracted. 
 
 FIG. 301 
 
 Fig. 301 shows a portion of the rim of this style of 
 wheel with its symmetrical double buckets. The steam jet 
 is split into two symmetrical parts by the sharp middle par- 
 tition. The direction of flow of the two steam streams 
 is now reversed, and they are returned to the middle plane 
 of the wheel by the reverse blades, and again brought to the 
 wheel as a united jet. Nearly the entire periphery has 
 primary, or secondary admission, and as a result of thi? 
 the fan work of the idle blades is reduced to a minimum. 
 
Disposal of the Exhaust Steam of 
 Steam Turbines 
 
 As in the case of the reciprocating engine, the highest 
 efficiency in the operation of the steam turbine is obtained 
 by allowing the exhaust steam to pass into a condenser, 
 and experience has demonstrated that it is possible to main- 
 tain a higher vacuum in the condenser of a turbine than in 
 that of a reciprocating engine. This is due, no doubt, to 
 the fact that in the turbine the steam is expanded down 
 to a much lower pressure than is possible with the recipro- 
 cating engine. 
 
 The condensing apparatus used in connection with steam 
 turbines may consist of any one of the modern improved 
 systems, and as no cylinder oil is used within the cylinder 
 of the turbine, the water of condensation may be returned 
 to the boilers as feed water. If the condensing water is 
 foul or contains matter that would be injurious to the 
 boilers, a surface condenser should be used. If the water 
 of condensation is not to be used in the boilers, the jet 
 system may be employed. Another type of condenser that 
 is being successfully used with steam turbines is the Bulk- 
 ley injector condenser. 
 
 Among the steam turbines that were on exhibition at the 
 St. Louis exposition in 1904 the Westinghouse-Parsons and 
 the General Electric Curtis turbines were each equipped 
 with Worthington surface condensers, fitted with improved 
 auxiliary apparatus consisting of dry vacuum pumps, either 
 horizontal of the well-known Worthington type, or rotative 
 
 123 
 
124 Steam Engineering 
 
 motor-driven, a hot well pump, and a pump for disposing 
 of the condensed steam from the exhaust system. The two 
 latter pumps were of the Worthington centrifugal type. 
 The Hamilton-Holzwarth turbine was equipped with a 
 Smith- Vaile surface condenser, fitted with a duplex double- 
 acting air pump, a compound condensing circulating pump, 
 and a rotative dry vacuum pump, motor-driven. The 
 vacuum maintained was high, 28 to 28.5 in. 
 
 As an instance of the great gain in economy effected by 
 the use of the condenser in connection with the steam tur- 
 bine, a 750 K. W. Westinghouse-Parsons turbine, using 
 steam of 150 Ibs. pressure not superheated and exhausting 
 into a vacuum of 28 in., showed a steam consumption of 
 13.77 Ibs. per B. H. P. per hour, while the same machine 
 operating non-condensing consumed 28.26 Ibs. of steam per 
 B. H. P. hour. Practically the same percentage in economy 
 effected by condensing the exhaust applies to the other 
 types of steam turbines. 
 
 With reference to the relative cost of operating the sev- 
 eral auxiliaries necessary to a complete condensing outfit, 
 the highest authorities on the subject place the power con- 
 sumption of these auxiliaries at from 2 to 7 per cent of the 
 total turbine output of power. A portion of this is re- 
 gained by the use of an open heater for the feed water, 
 into which the exhaust steam from the auxiliaries may 
 pass, thus heating the feed water and returning a part of 
 the heat to the boilers. 
 
 A prime requisite to the maintenance of high vacuum, 
 with the resultant economy in the operation of the con- 
 densing apparatus, is that all entrained air must be ex- 
 cluded from the condenser. There are various ways in 
 which it is possible for air to find its way into the con- 
 
Exlawd Steam 125 
 
 densing system. For instance, there may be an improperly 
 packed gland, or there may be slight leaks in the piping, or 
 the air may be introduced with the condensing water. This 
 air should be removed before it reaches the condenser, and 
 it may be accomplished by means of the "dry" air pump. 
 
 This dry air pump is different from the ordinary air 
 pump that is used in connection with most condensing 
 systems. The dry air pump handles no water, the cylinder 
 being lubricated with oil in the same manner as the steam 
 cylinder. The clearances also are made as small as possi- 
 ble. These pumps are built either in one or two stages. 
 
 A barometric or a jet condenser may be used, or a surface 
 condenser. The latter type lessens the danger of entrained 
 air, besides rendering it possible to return the condensed 
 steam, which is pure distilled water, to the boilers along 
 with the feed water, a thing very much to be desired in 
 localities where the water used for feeding the boilers is 
 impregnated with carbonate of lime, or other scale-form- 
 ing ingredients. 
 
 In comparing the efficiency of the reciprocating engine 
 and the steam turbine it is not to be inferred that recipro- 
 cating engines would not give better results at high vacuum 
 than they do at the usual rate of 25 to 26 in., but to reach 
 and maintain the higher vacuum of 28 to 28.5 in. with the 
 reciprocating engine would necessitate much larger sizes 
 of the low-pressure cylinder, as also the valves and exhaust 
 pipes, in order to handle the greatly increased volume of 
 steam at the low pressure demanded by high vacuum. 
 
 The steam turbine expands its working steam to within 
 1 in. of the vacuum existing in the condenser, that is, if 
 there is a vacuum of 28 in. in the condenser there will be 
 27 in. of vacuum in the exhaust end of the turbine cylinder. 
 
!';?(> Steam Engineering 
 
 On the other hand, there is usually a difference of 4 or 5 
 in (2 to 2.5 Ibs.) between the mean back pressure in the 
 cylinder of a reciprocating condensing engine, and the 
 absolute back pressure in the condenser. 
 
 It therefore appears that the gain in economy per inch 
 increase of vacuum above 25 in. is much larger with the 
 turbine than it is with the reciprocating engine. Mr. J. R. 
 Bibbins estimates this gain to be as follows : between 25 and 
 28 in. there is a gain of 31/2 to 4 per cent per inch of in- 
 crease, and at 2& in. 5 per cent. These results have been 
 obtained by means of exhaustive tests conducted by Mr. 
 Bibbins. Other high authorities on the steam turbine all 
 agree as to the great advantages to be derived by incurring 
 the extra expense of erecting a condensing plant that is 
 capable of maintaining the high vacuum necessary to high 
 efficiency. 
 
 Another method by which the steam consumption of the 
 turbine may be materially decreased, and a great gain in 
 economy effected is by superheating the steam. The amount 
 of superheat usually specified is 100, and the apparatus 
 employed for producing it may be easily mounted in the 
 path of the waste gases. The steam may thus be super- 
 heated without extra cost in fuel, and an increase of 8 to 
 10 per cent in economy effected. The independent super- 
 heater requires extra fuel and labor, and the gain in this 
 case is doubtful, but there can be no question as to the wis- 
 dom of utilizing the waste flue gases for superheating the 
 steam. 
 
 As previously stated, the steam turbine is peculiarly 
 adapted for the use of highly superheated steam, and high 
 vacuum, and in these two particulars it excels the recipro- 
 cating engine. At the present time many large plants are 
 
Exhaust Steam 127 
 
 equipped with turbine engines that are giving the best of 
 results., and the outlook for the future employment of this 
 type of power producer is certainly very promising. 
 
 Surface Condensers. The demand for efficient service in 
 the production of power by both the reciprocating engine, 
 and the steam turbine has resulted in bringing to bear upon 
 the design of the surface condenser, some of the thought, 
 study and experiment which have heretofore been expended 
 upon the other factors of the power plant. Up to within 
 the past few years the surface condenser consisted princi- 
 pally of an indiscriminate collection of tubes within a metal 
 box, with a flood of water following what happened to be the 
 path of least resistance, with tubes subjected upon the steam 
 side to a shower of water of condensation, keeping the steam 
 from contact, and with pockets and quiet corners for steam 
 and air and water, with an air-pump large enough for what- 
 ever happened, and little attention paid to the getting of 
 the air into it, the surface condenser has satisfied the mod- 
 erate demands of the past, and awaited the demands created 
 by the turbine, and the strenuous central station man for 
 scientific treatment along rational lines. 
 
 In a condenser taking care of 200,000 pounds of steam 
 per hour, over 55 pounds of water are made upon the tubes 
 per second. If this has to drip down over the bank below 
 the point at which it is formed, it can readily be seen that 
 the lower tubes are going to be busy cooling off feed-water 
 instead of condensing steam, and that the greater rate of 
 condensation will occur upon the upper tubes. By arrang- 
 ing the tubes in banks, the condensation from each of which 
 is quickly drawn to the side and disposed of, by leading 
 the steam to a positive and rapid flow among these tubes 
 in a direction counter to the flow of the water, so that the 
 
128 Steam Engineering 
 
 final contact of the condensed steam and air is with ,the 
 coolest water, and by subdividing the flow so that the circu- 
 lating water travels positively and rapidly past every square 
 foot of the cooling surface, the condenser is made to con- 
 dense eighten or twenty instead of six pounds of steam per 
 hour per square foot of surface. The significance of this, 
 not only in first cost and space occupied, but in mainte- 
 nance charges where, as in some of the large stations upon 
 the Atlantic seaboard, tubes have to be renewed once in 
 about three years, is easy to appreciate, and it is not the tube 
 which is condensing lots of steam, but rather that which is 
 loafing in an air pocket or an eddy, that is the most likely 
 to corrode. 
 
 Notwithstanding the liability to corrosion of the tubes 
 of surface condensers, many of the large engine plants, and 
 practically all steam turbine plants have been equipped 
 with surface condensers. This is due largely to the saving 
 effected by returning the pure water of condensation to 
 the boilers. But unless the condenser tubes are closely 
 watched for signs of corrosion, there is danger of having 
 in the course of time a mixture of cylinder oil and con- 
 denser leakage along with the water of condensation, which 
 would be a very undesirable boiler feed. This applies to 
 reciprocating engine plants. On the other hand a surface 
 condenser in connection with a steam turbine is a better 
 investment. The turbine water of condensation contains 
 no lubricating oil and condenser leakage is the only source 
 of trouble to be feared. To maintain this condenser leak- 
 age at the lowest practicable minimum is extremely im- 
 portant, as this will seriously affect (if the hot-well water 
 is used for boiler feed) the percentage of corrosive and 
 scale-forming elements fed into the boilers. Even under 
 
Questions and Answers 129 
 
 normal surface-condenser operation there is a small leakage, 
 through the packing at the ends of the tubes, and to this 
 is added leakage due to corrosion. 
 
 The danger of corrosion attacking the tubes of surface 
 condensers is much greater in localities upon, or near the 
 sea coast where the condensing water is largely impreg- 
 nated with salt. 
 
 QUESTIONS AND ANSWERS. 
 
 446. Explain the chief points of difference between 
 the action of the reciprocating steam engine, and the steam 
 turbine. 
 
 Ans. The piston of the reciprocating engine is driven 
 back and forth by the static expansive force of the steam ; 
 while in the steam turbine, not only is this static expansive 
 force made to do work, but the velocity of the steam in ex- 
 panding from a high, to a low pressure is also utilized in 
 turning the rotor of the turbine. 
 
 447. What other important factors enter into the opera- 
 tion of a steam turbine? 
 
 Ans. The principles of reaction and impulse. 
 
 448. Name several of the more important advantages 
 that the turbine has over the reciprocating engine. 
 
 Ans. First, highly superheated steam of a high initial 
 pressure may be used in the turbine. Second, a larger 
 proportion of the heat in the steam may be converted into 
 work with the turbine. Third, there is much less friction 
 with the turbine. 
 
 449. What is the most economical method of disposing 
 of the exhaust steam from a turbine? 
 
 Ans. By allowing it to pass into a condensei. 
 
130 Steam Engineering 
 
 450. Will the turbine expand the steam to as low n 
 pressure as the reciprocating engine will? 
 
 Ans. Yes, and even lower. 
 
 451. What type of condensing apparatus is necessary 
 with the steam turbine. 
 
 Ans. The same kind that is used on reciprocating en- 
 gines. 
 
 452. How low will a well regulated turbine allow the 
 steam to expand ? 
 
 Ans. To within one inch of the vacuum existing in 
 the condenser. 
 
 453. What is the theoretical velocity of steam under 
 100 Ibs. pressure if allowed to discharge into a vacuum of 
 28 inches? 
 
 Ans. 3860 feet per second. 
 
 454. How many ft. Ibs. of energy would one cubic ft. 
 of steam thus exert? 
 
 Ans. 59,900 ft. Ibs. 
 
 455. What is the ratio of bucket speed to jet speed for 
 impulse wheels. 
 
 Ans. Bucket speed equals one-half of jet speed. 
 
 456. What should be the ratio between bucket speed 
 and jet speed, for reaction wheels. 
 
 Ans. 1 to 1. That is, the two speeds should be equal. 
 
 457. What should be the form or curvature of the 
 blades, or buckets? 
 
 Ans. They should be of such form as will permit expan- 
 sion of the steam with the least amount of friction, or eddy 
 currents. 
 
 458. How are the stuffing boxes of steam turbines usu- 
 ally kept cooled? 
 
 Ans. By means of water applied in various ways. 
 
Questions and Answers 131 
 
 459. How is the speed of steam turbines usually regu- 
 lated ? 
 
 Ans. By simple throttling. 
 
 460. What are the ideal conditions under which a tur- 
 bine should work? 
 
 Ans. A full initial pressure, and all cross sections of 
 steam passages to be suitable to the power required. 
 
 461. Of what type is the Westinghousc-Parsons turbine ? 
 Ans. It is both an impulse and reaction turbine. 
 
 462. How are the clearances between the blades pre- 
 served in this turbine? 
 
 Ans. By means of balancing pistons on the shaft. 
 
 463. What is the usual velocity of the steam in the 
 Westinghouse-Parsons turbine ? 
 
 Ans. 600 ft. per second. 
 
 464. How does the efficiency of steam turbines compare 
 with that of reciprocating engines? 
 
 Ans. It is generally higher. 
 
 465. How is the heat energy in the steam imparted to 
 the wheels of the Curtis turbine? 
 
 Ans. Both by impulse and reaction. 
 
 466. Describe the method of admission in the Curtis 
 turbine. 
 
 Ans. The steam is admitted through expanding nozzles 
 in which nearly all of the expansive force of the steam is 
 transformed into the force of velocity. The steam is caused 
 to pass through one, two, or more stages of moving ele- 
 ments, each stage having its own set of expanding nozzles, 
 each succeeding set of nozzles being greater in number and 
 of larger area than the preceding set. 
 
 467. What is the ratio of expansion in these nozzles? 
 
132 Steam Engineering 
 
 Ans. The ratio of expansion within these nozzles de- 
 pends upon the number of stages, as, for instance, in a two- 
 stage machine, the steam enters the initial set of nozzles at 
 boiler pressure, say 180 Ibs. It leaves these nozzles and 
 enters the first set of moving blades at a pressure of about 
 15 Ibs. 
 
 468. In a four-stage machine, with 180 Ibs initial pres- 
 sure, what would be the pressures at the different stages? 
 
 Ans. First stage, 50 Ibs. ; second stage, 5 Ibs. ; third 
 stage, partial vacuum, and fourth stage, condenser vacuum. 
 
 469. How are the revolving parts of the Curtis turbine 
 supported ? 
 
 Ans. Upon a vertical shaft, which in turn is supported 
 by, and runs upon a step bearing at the bottom. 
 
 470. How is this step bearing lubricated? 
 
 Ans. Oil is forced under pressure by a steam or elec- 
 trically driven pump, the oil passing up from beneath. 
 
 471. How is the speed of the Curtis turbine regulated? 
 Ans. By varying the number of nozzles in flow. 
 
 472. How are the clearances adjusted in the Curtis 
 turbine ? 
 
 Ans. By means of the large step screw at the bottom. 
 
 473. How is the shaft packed to prevent steam leakage ? 
 Ans. With carbon blocks made into rings fitting the 
 
 shaft. 
 
 474. What type of turbine is the De Laval ? 
 Ans. It is purely an impulse wheel. 
 
 475. What is the speed of the wheel ? 
 
 Ans. From 10,000 to 30,000 revolutions per minute. 
 
 476. How is the heat energy in the steam utilized in 
 the De Laval turbine? 
 
 Ans. In the production of velocity. 
 
Questions and Answers 133 
 
 477. What is the velocity of the steam as it issues from 
 the expanding nozzles and impinges against the buckets? 
 
 Ans. About 4,000 ft. per second. 
 
 478. What is the usual peripheral speed of the wheel? 
 Ans. 1,200 to 1,300 feet per second. 
 
 479. Of what type is the Allis-Chalmers steam turbine? 
 Ans. It is essentially of the Parsons type. 
 
 480. How are the clearances between the revolving and 
 stationary blades preserved? 
 
 Ans. By a thrust bearing. 
 
 481. What kind of bearings has the Allis-Chalmers 
 turbine ? 
 
 Ans. Self-adjusting ball and socket bearings. 
 
 482. What is the first move in preparing to start a 
 steam turbine? 
 
 Ans. Open the throttle slightly and allow a small vol- 
 ume of steam to flow through in order to warm the tur- 
 bine. 
 
 483. What should be done next? 
 Ans. Start the auxiliary oil pump. 
 
 484. What are the principal precautions to be observed 
 when starting a steam turbine? 
 
 Ans. To see that the turbine is properly warmed, also 
 to be certain that the oil is circulating freely through the 
 bearings. 
 
 485. What type of turbine is the Hamilton-Holzwarth 
 steam turbine? 
 
 Ans. It is an impulse turbine. 
 
 488. Describe in brief its construction? 
 
 Ans. There are no balancing pistons in this machine, 
 the axial thrust of the shaft being taken up by a thrust 
 ball-bearing. The interior of the cylinder is divided into 
 
134 Steam Engineering 
 
 a series of stages by stationary discs which are set in 
 grooves in the cylinder and are bored in the center to allow 
 the shaft, or rather the hubs of the running wheels that are 
 keyed to the shaft, to revolve in this bore. 
 
 487. In what respect does this turbine resemble a com- 
 pound reciprocating engine? 
 
 Ans. The steam is first admitted to the high pressure 
 casing, and from there it passes into the low pressure cas- 
 ing, which is larger in diameter. 
 
 488. Describe the action of the steam upon the blades ? 
 Ans. The expansion of the steam takes place entirely 
 
 within the stationary blades, which also change the direc- 
 tion of its flow, distributing it to the running vanes. 
 
 489. What additional function do the stationary vanes 
 perform ? 
 
 Ans. They take the back pressure, thus acting as balanc- 
 ing pistons. 
 
 490. What type of governor has this turbine? 
 Ans. The spring and weight type. 
 
 491. How are the bearings lubricated ? 
 
 Ans. The oil is forced into the bearings under pressure 
 by an oil pump. 
 
 492. Of what type is the Rateau steam turbine? 
 
 Ans. It is an impulse turbine having wheels of thin 
 plates, slightly conical. 
 
 493. How is the rotor balanced? 
 
 Ans. The same pressure exists on both sides of each 
 rotating wheel. 
 
 494. Does the steam act by velocity or pressure? 
 Ans. By velocity in this case. 
 
 495. What are the essential features of the Eeidler- 
 Stumpf steam turbine ? 
 
Questions and Answers 135 
 
 Ans. The peculiar form of bucket, and the parallel 
 return of the steam. 
 
 496. What is meant by parallel return of the steam? 
 Ans. The steam enters the buckets through nozzles, 
 
 and is deflected through an angle of 180 degrees, thus leav- 
 ing the rotating buckets in a direction parallel to that of 
 its entrance. 
 
 497. Describe the action of the steam within the Reid- 
 ler-Stumpf turbine. 
 
 Ans. Instead of escaping after having once passed 
 through the buckets, it is caught by the guides or stationary 
 buckets and returned to the wheel; this process being re- 
 peated again, and again until all of the energy in the steam 
 has been made to do work. 
 
 498. How many types of this turbine are there ? 
 
 Ans. Two, viz. : The single flow, and the double flow. 
 
 499. How is the highest efficiency obtained in the oper- 
 ation of the steam turbine ? 
 
 Ans. By allowing the exhaust steam to pass into a 
 condenser. 
 
 500. Is it possible to maintain as high vacuum with 
 the turbine as with a reciprocating engine? 
 
 Ans. Experience demonstrates that a higher vacuum 
 may be maintained in the condenser of a turbine than is 
 possible with reciprocating engines. 
 
 501. What kind of condensing apparatus may be used 
 with steam turbines? 
 
 Ans. Any one of the modern improved types. 
 
 502. What is required in order to maintain a high 
 vacuum in any type of condenser? 
 
 Ans. That all entrained air be excluded. 
 
 503. How may this be accomplished? 
 
136 Steam Engineering 
 
 Ans. By means of a dry air pump. 
 
 504. In what manner does the dry air pump differ from 
 an ordinary air pump? 
 
 Ans. The dry air pump handles no water, and the clear- 
 ances are made as small as possible. 
 
 505. To what extent does the steam turbine expand its 
 working steam? 
 
 Ans. To within one inch of the vacuum existing within 
 the condenser. 
 
 506. Is the steam turbine adapted to the use of super- 
 heated steam? 
 
 Ans. It is. Highly superheated steam may be used, and 
 a high vacuum maintained. 
 
 507. Is the water of condensation from turbines desir- 
 able for boiler feed ? 
 
 Ans. It is, for the reason that it contains no lubricating 
 oil, and is a comparatively pure water. 
 
INDEX 
 
 A 
 
 Allis-Chalmers Steam Turbine 75-88 
 
 Action of steam in 78 
 
 Balance pistons 79 
 
 Bearings 81-82 
 
 Blades 78-81 
 
 Description of 75-77 
 
 General view of 76 
 
 Governor 81 
 
 Starting and operating 84-88 
 
 Thrust bearing 79 
 
 B 
 
 Blade Form of 12-13 
 
 Branca's Turbine 10 
 
 C 
 
 Catechism 129-136 
 
 Condensers 123 
 
 Curtis Steam Turbine 37-58 
 
 Action of steam in 34-44 
 
 Admission valves 43 
 
 Baffler 58 
 
 Clearance 55-56 
 
 Governor 48-52 
 
 Initial nozzles and buckets 36-40 
 
 Shaft 37 
 
 Speed regulation 44-48 
 
 Step bearing 55 
 
 Wheels and stages 38-41 
 
 D 
 
 De Laval Steam Turbine 59-60 
 
 Action of steam in 66-68 
 
 Description of parts 62-68 
 
 i 
 
ii Index 
 
 Efficiency tests of 72-73 
 
 Gear Flexible shaft 66-67 
 
 Governor , 68-69 
 
 High speed of 59-62 
 
 Nozzles 60 
 
 Wheel 73 
 
 E 
 Efficiency of Steam Turbines 29-30 
 
 F 
 Form of turbine blade 12-13 
 
 G 
 
 General suggestions 88 
 
 Governor 27, 48, 68 
 
 H 
 
 Hamilton-Holzwarth Steam Turbine 89-105 
 
 Action of steam in 83-84 
 
 Catechism on 133-135 
 
 Clearance of blades 92-94 
 
 Comparison with other types 91-92 
 
 Construction of blades 94-95 
 
 Governor Regulation 85-87 
 
 Running wheels 95-9!) 
 
 Stationary discs S4-N5 
 
 Stuffing box 103-105 
 
 I 
 
 Initial Nozzles and Buckets 36-40 
 
 Invention of the steam turbine 7, 20 
 
 L 
 Labyrinth Stuffing Box 13-14 
 
 O 
 Operation of Steam Turbines 17,48,88 
 
Index iii 
 
 P 
 
 Piping 51 
 
 Precautions 50 
 
 R. 
 
 Rateau Steam Turbine 107-117 
 
 Action of steam in 108-110 
 
 Principles of 108 
 
 Regenerator for low pressures 110-116 
 
 Regulation of Steam Turbines 17 
 
 S 
 
 Steam Turbine 7-12 
 
 Allis-Chalmers 75-88 
 
 Curtis 37-58 
 
 De Laval 59-60 
 
 Hamilton-Holzwarth 89-105 
 
 Rateau 107-117 
 
 Reidler-Stumpf 119-122 
 
 Starting Rules for 84 
 
 Stopping Rules for 87-88 
 
 Stuffing Boxes 13-17 
 
 Allis-Chalrners 82 
 
 Curtis 58 
 
 De Laval 68 
 
 Hamilton-Holzwarth 103-105 
 
 Rateau 15-16 
 
 W 
 
 Westinghouse- Parsons Steam Turbine 19-36 
 
 Admission nozzles 33-37 
 
 Balancing pistons 24-25 
 
 Blade material 29-30 
 
 Capacity of 19 
 
 Catechism on 131-132 
 
 Direction of steam through 24 
 
 Double flow type 30-36 
 
 Efficiency of 29 
 
 ( Jovernor 27-28 
 
Practical Mechanical Drawing 
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 nearly 100 illustrations are used, which, with perhaps a very few excep- 
 tions, have been especially made for this book. There are many tables 
 covering all sorts of electrical matters, so that immediate reference can 
 be made without resorting to figuring. It covers the subject thoroughly, 
 but so simply that any one can understand it fully. Any one making a 
 pretense to electrical engineering needs this book. Nothing keeps a man 
 down like the lack of training; nothing lifts him up as quickly or as 
 surely as a thorough, practical knowledge of the work he has to do. This 
 book was written for the man without an opportunity. No matter what 
 he is, or what work he has to do, it gives him just such information 
 and training as are required to attain success. It teaches just what 
 the steam engineer should know in his engine room about electricity. ., 
 12mo, Cloth, 10O Illustrations. Size5%x7%. PRICE NET l PA 
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The Calculation of Horse 
 Power Made Easy : : : 
 
 By L. ELLIOTT BROOKES 
 
 Author of "Gas and Oil Engine Hand-Book," 
 "The Automobile Hand-Book," Etc. 
 
 Size, 5x7%. 80 Pages, Illustrated. Cloth, 75 Cents 
 
 THIS work deals in a practical and non- 
 technical manner with the calculation 
 of the power of Steam Engines, *Explo- 
 sive and Electric Motors. 
 
 Particular attention has been given to the 
 full explanation of the elementary principles 
 upon which the calculations are based. 
 
 It has been the endeavor to present in as 
 simple a manner as is possible, a number of 
 useful rules and formulas that may be of 
 great va,lue to ENGINEERS, MACHINISTS and 
 DESIGNERS in calculating horse power. 
 
 Rules for plotting steam engine diagrams 
 by arithmetical, geometrical and graphical 
 methods are given and fully explained, also 
 the method used in plotting the diagram of 
 an explosive motor. 
 
 This work covers many points regarding 
 the calculation of horse power and useful 
 information not hitherto published in a single 
 
 volume, and includes Calculated, Brake and Indicated horse power, Point of 
 cut-off and average steain pressure, Horse Power of Explosive Motors, Degree 
 of Compression and Combustion Chamber Dimensions, Indicator Diagrams of 
 Steam Engines and Explosive Motors, also tables of Average Steam Pressure, 
 Areas of Circles, Squares of Diameters of Circles, Natural Logarithms of Num- 
 bers, Thermo-dynamic Properties of Gasoline and Air, Common Logarithms 
 of Numbers, and Mensuration of Surface and Volume. 
 
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MODERN ELECTRICAL 
 CONSTRUCTION 
 
 By HORSTMANN and TOUSLEY - 
 
 77THIS book treats almost entirely of practical electrical 
 ^^ work. It uses the ' 'Rules and Requirements of the Na- 
 tional Board of Fire Underwriters" as a text, and ex- 
 plains by numerous cuts and detailed explanations just how 
 
 the best class of electrical 
 work is installed. 
 
 It is a perfect guide for 
 the beginning electrician 
 and gives him all the 
 theory needed in practical 
 work in addition to full 
 practical instructions. For 
 the journeyman electrician 
 it is no less valuable, be- 
 cause it elaborates and 
 explains safety rules in 
 vogue throughout the 
 United States. It is also 
 of especial value to elec- 
 trical inspectors, as it 
 points out many of the 
 tricks practiced by un- 
 scrupulous persons in the 
 trade. 
 
 The book also contains a 
 number of tables giving di- 
 mensions and trade num- 
 bers of screws, nails, in- 
 sulators and other material 
 in general use, which will be found of great value in practice. 
 There is also given a method by which the diameter of con- 
 duit necessary for any number of wires of any size can be at 
 once determined. The motto of the authors, "To omit noth- 
 ing that is needed and include nothing that is not needed, " 
 that has made "Wiring diagrams and Descriptions" so suc- 
 cessful, has been followed in this work. No book of greater 
 value to the man who does the work has ever been published. 
 16mo, 250 pages, 100 diagrams. Full leather, limp. 
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COMPLETE EXAMINATION 
 QUESTIONS AND ANSWERS 
 
 FOR MARINE AND 
 STATIONARY ENGINEERS 
 
 By Calvin F. Swingle, M. E. Author of Swingle's Twentieth 
 Century Hand Book for Steam Engineers and Electricians. 
 Modern Locomotive Engineering Handy Book, and 
 Steam Boilers Their construction, care and management 
 
 /TfHIS book is a compendium of 
 ^ useful knowledge, and prac- 
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 any more time at study than is ab- 
 solutely necessary, the book wiL 
 prove a rich mine from which they 
 may draw nuggets of just the kind 
 of information that they are look- 
 ing for. 
 
 The method pursued by the au- 
 thor in the compilation of the work 
 and in the arrangement of the sub- 
 ject matter, is such that a man in 
 search of any particular item of in- 
 formation relative to the operation 
 of his steam or electric plant, will 
 experience no trouble in rinding 
 that particular item, and he will not 
 be under the necessity of going 
 over a couple of hundred pages, 
 either, before he finds it because 
 the matter is systematically ar- 
 ranged and classified. 
 The book will be a valuable addition to any engineer's library, nor 
 alone as a convenient reference book, but also as a book for study. It 
 also contains a complete chapter on refrigeration for engineers. 300 
 pages fully illustrated, durably bound in full Persian Morocco limp, 
 round corners, red edges. 
 
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Twentieth Century 
 Machine Shop Practice 
 
 By L. ELLIOTT BROOKES 
 
 The best and latest and most 
 practical work published on mod- 
 ern machine shop practice. This 
 book is intended for the practical 
 instruction of Machinists, Engin- 
 eers and others who are interested 
 in the use and operation of the 
 machinery and machine tools in a 
 modern machine shop. The first 
 portion of the book is devoted to 
 practical examples in Arithmetic, 
 Decimal Fractions, Roots of Num- 
 bers, Algebraic Signs and Symbols, 
 Reciprocals and Logarithms of 
 Numbers, Practical Geometry and 
 and Mensuration. Also Applied 
 Mechanics which includes : The 
 lever, The wheel and pinion, The 
 pulley, The inclined planes, The 
 wedge The, screw and safety valve 
 Specific gravity and the velocity 
 of falling bodies Friction, Belt 
 Pulleys and Gear wheels. 
 
 Properties of steam. The Indi- 
 cator, Horsepower and Electricity. 
 
 Tb-. latter part of the book gives full and complete information 
 upon the following subjects: Measuring devices, Machinists' tools, 
 Shop tools, Machine tools, Boring machines, Boring mills. Drill 
 presses, Gear Cutting machines, Grinding Machines, Lathes and Mill- 
 ing machines. Also auxiliary machine tools. Portable tools, Miscella- 
 neous tools, Plain and Spiral Indexing machines, Notes on Steel. Gas 
 furnaces, Shop talks, Shop kinks, Medical Aid and over Fifty tables. 
 
 The book is profusely illustrated and shows views of the latest 
 machinery and the most up-to-date and improved belt and motor- 
 driven machine tools, with full information as to their use and opera- 
 tion. It has been the object of the author to present the subject 
 matter in this work in as simple and not technical manner as is 
 possible. 
 
 12mo, cloth, 636 pages, 456 fine illustration?, price, $2.00 
 
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 any address upon receipt of Price by the Publishers 
 
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THE KING OF ALL The Companion Volume to Modern 
 Wiring Diagrams Just from the Press 
 
 Electrical Wiring *<r 
 Construction Tables 
 
 By Henry C. Horstmann and Victor H. Tousley 
 
 Contains hundreds of easy up-to-date tables covering everything on 
 
 Electric Wiring. Bound in full Persian Morocco. 
 
 Pocket size. Round corners, red edges. 
 
 PRICE, NET, $1.50 
 
 Partial Table of Contents 
 
 This Book contains 
 
 among others: 
 
 Tables for direct current 
 calculations. 
 
 Tables for alternating cur- 
 icnt calculations. 
 These tables show at a 
 glance the currents re- 
 quired with any of the 
 systems in general use, 
 fcr any voltage, effici- 
 ency, or power-factor, 
 and by a very simple 
 calculation (which can 
 be mentally made), also 
 the proper wire for any 
 less. 
 
 Tables showing the small- 
 est wire permissable 
 with any system or num- 
 ber of H. P. or lights 
 under "National Electri- 
 cal Code" or Chicago 
 rules. Very convenient 
 for contractors. 
 
 Tables for calculating the 
 most economical loss. 
 
 Tables and diagrams 
 showing proper size of 
 conduits to accommo- 
 date all necessary combinations or 
 number of wires. 
 
 Tables and data for estimating at a 
 glance the quantity of material re- 
 quired in different lines of work. 
 
 A3 this is intended for a pocket-hand-book everything that would 
 ** makes it unnecessarily cumbersome is omitted. There is no 
 padding. Every page is valuable and a time saver. This book will 
 be used every day be the wireman, the contractor, engineer and 
 architect. All parts are so simple thai verv ''ttle electrical knowl- 
 edge is required to understand them. 
 
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The Practical Gas & 
 
 Oil Engine HAND-BOOK 
 
 II 
 
 ..'S;:-'-P;V.v"-:.v.' ; : .-." .'.*." "''." "' 
 
 A MANUAL of useful in- 
 ** formation on the care, 
 maintenance and repair of Oas 
 and Oil Engines. 
 
 This work gives full and 
 clear instructions on all points 
 relating to the care, mainte- 
 nance and repair of Stationary, 
 Portable and Marine, Gas and 
 Oil Engines, including How to 
 Start, How to Stop, How to Ad- 
 just, How to Repair, How to 
 Test. , 
 
 Pocket size, 4x6H. Over 
 200 pages. With numerous 
 rules and formulas and dia- 
 grams, and over 50 illustrations 
 by L. ELLIOTT BROOKES, au- 
 thor of the "Construction of a 
 Gasoline Motor," and the "Au- 
 tomobile Hand-Book." 
 
 This book has been written 
 with the intention of furnishing 
 practical information regarding 
 gas, gasoline and kerosene engines, for the use of owners, operators and 
 others who may be interested in their construction, operation and man- 
 agement. 
 
 In treating the various subjects it has been the endeavor to avoid all 
 technical matter as far as possible, and to present the information given 
 in a clear and practical manner. 
 
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Easy Electrical Experiment* 
 and How to Make Them 
 
 By L. P. DICKINSON 
 
 This is the very latest and mosi 
 valuable work on Electricity for the 
 amateur or practical Electrician pub- 
 lished. It gives in a simple and 
 easily understood language every 
 thing you should know about Gal- 
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 duction, Coils, Motors, Voltmeters, 
 Dynamos., Storage Batteries, Simple 
 and Practical Telephones, Telegraph 
 Instruments, Rheostat, Condensers, Electrophorous, 
 Resistance, Electro Plating, Electric Toy Making, etc. 
 The book is an elementary hand book of lessons, 
 experiments and inventions. It is a hand book for 
 beginners, though it includes, as well, examples for 
 the advanced students. The author stands second to 
 none in the scientific world, and this exhaustive work 
 will be found an invaluable assistant to either the 
 Student or mechanic. 
 
 Illustrated with hundreds of fine drawings; printed! 
 on a superior quality of paper. 
 
 J2mo Cloth. Price, $1.25, 
 
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YB 1076