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 On the Wooden Graving 
 Dock, at St. John's, Nfld. 
 
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 By ErHfKEATING, C K. 
 
 
 <^nmyi>^ 
 
 ERRATUM. 
 
 Page 167, on the 12th line from the top, for "shortened," read 
 "hastened." - 
 
City Engineer's Office, 
 
 Halifax, N.S., 26th Dec, 1881 
 
 To His Worship the Mayor, Chairman Dry Dook Committee 
 
 Sir, — Having been requested to proceed to St. John's, 
 Newfoundland, to be present at the opening of the new 
 wooden graving dock just completed at that port, I beg to 
 submit the following report : — 
 
 Friday, the 5th of December, was the day appointed for the 
 formal opening of the dock, but owing to delay in removing 
 the temporary coffer-dam at the entrance, the ceremony did 
 not take place until the afternoon of Wednesday, the 10th 
 inst., at which time H. M. S. Tenedos was hauled into the dock 
 and the water was pumped out during the night. There was 
 no demonstration of any kind on the occasion. 
 
 The harbor of St. John's is limited in : stent, being about a 
 mile and a half in length by not over half a mile in breadth in 
 the widest place. 
 
 The dock is admirably situated for the purpose for -which 
 it is intended, at the head of the harbor on a site which could 
 scarcely have been more favorable for construction purposes. 
 A large part of the area was formerly bare at low tide while 
 the remaining portion was in shallow water. The whole of 
 the material requiring excavation was of the easiest possible 
 description to be removed, being deposits of river mud. sand 
 and gravel brought down by a rivulet which discharges its 
 waters at the upper end of the harbor locally called " River- 
 head." 
 
 An agreement between the Government of the Colony and 
 Messrs. J. E. Simpson &; Co., of New York, was entered into 
 on the l7th March, 1883, for the construction of the works, 
 and was ratified by an Act of Parliament passed on the 21st 
 of April of the same year. 
 
 Under the agreement the Government provided the site free 
 of cost to the contractors, admitted all materials and machinery 
 
162 DRY DOCK. 
 
 required exempt from customs' dues, and stipulated to pay the 
 sum of $550,000 in monthly instalments, at the rate of 85 per 
 cent, on the value, according to a certain schedule of prices:, 
 the balance of 15 per cent, being payable on completion. 
 
 The contractors on their part agreed to furnish all the 
 materials, plant, machinery and labor required imder the 
 terms of the specifications, and to complete the whole of the 
 works within a period of twenty-four months. 
 
 The agreement also contains a stipulation that the con- 
 tractors shall, on the completion of the works, lease them from 
 the Government and keep them in repair for a term of ten 
 years at a rental of $15,000 per annum. 
 
 The contract price for the dock alone without the gate, 
 engine-house, pumping machinery or other necessary appur- 
 tenances was $216,602. 
 
 The following is a synopsis of the various items included in 
 the contract with the price set opposite to each : 
 
 Plans, Specifications and Engineering S 25,470 00 
 
 Cofter-dam 28,810 00 
 
 Bulkheads 2-5,160 00 
 
 Engine-house and Culverts 12,560 00 
 
 Pumping during construction 18,000 00 
 
 Pumps, Boilers and Connections 36,600 00 
 
 Caisson, fitted complete 35,408 00 
 
 Removing temporary Coffer-dam 9,223 60 
 
 Capstans, Gipsies, &c 5,100 00 
 
 Freight-house and Work-shops 28,000 00 
 
 Piers 28,200 00 
 
 Excavation alongside Piers and Freight-house. . . 25,856 40 
 
 Filling, Grading and Excavation in Slips 26,010 00 
 
 Engine, Boiler and Tools in Work-shop 10,000 00 
 
 The Dock proper 216,602 00 
 
 Dredging Channel from piers to deep water 25,000 00 
 
 Total S556,000 00 
 
 It will be seen that the above contract amounts when 
 summed together exceed by $6,000 the bulk sun^, previously 
 alluded to as the total contract price of the works, I am 
 
DR'f DOCK. 163 
 
 i,nable to point out where the error is, as the discrepancy 
 €j:ists in the printed official papers to which I was referred 
 for information. 
 
 The dock is the largest structure of its kind in America, 
 being of the same length and draught of water as No. 2 dock 
 at Erie Basin, New York, while its width across the body is 17 
 feet greater on top and 3 feet 10 inches greater on the bottom. 
 
 Its principal dimensions are : 
 
 Extreme length inside at coping level from head 
 
 to caisson when at outer grove or sill . . 000 ft. 
 
 Extreme length at bottom on centre line of keel 
 
 blocks 558 ft. 
 
 Extreme width of body at coping level 132^ ft. 
 
 " " on floor 49 ft. 10 ins. 
 
 Depth of water over gate sill at high water, 
 
 Spring tide 25 ft. 
 
 The dock is pi-actically of the same shape and appearance as 
 all the other large wooden docks along the Atlantic coast of 
 America, with its sides flaring upwards from the bottom at 
 an angle of about 45 degrees. Every portion of the structure 
 ■exposed to view is composed of wood work. The short altars 
 which form the sides and head of the dock and nearly all of 
 the principal framing timbers are of pitch pine imported from 
 the Southern States. The gate sills, abutments and the gate 
 sill braces are American white oak. The foundation piles and 
 other piles required are specified to be of spruce not less than 
 12 inches in diameter at the butt and 6 inches at the smaller 
 end. The floor planks are 3 inch spruce. 
 
 The structure differs in one t..sential part from all other 
 wooden docks previously built by the same firm of contractors ; 
 its peculiar feature being that solid rock underlies the bottom 
 at a few feet below the flooring plank, thus rendering piling 
 in the usual way— over that portion of the dock which is the 
 deepest — an impossibility. 
 
 A hard conglomerate overlies the rock, and upon this is said 
 to have been placed from 2 to 4 feet of concrete, into which 
 were bedded iron ties secured by bolts to the floor timbers. 
 
 Around the sides and head of the dock, piles are driven and 
 the braces secured thereto in the customary manner. The 
 
164 DRY DOCK. 
 
 braces are spaced about four feet apart longitudinally, or at 
 right angles to the axis of the do jk, and the piles about 7 feet 
 apart traversely, those near the bottom altars naturally being 
 short on account of the close proximity of the rock. 
 
 behind the wooden face of the sides and head of the dock a 
 material resembling clay was deposited and rammed in for a 
 thickness of about two or two and half feet. The woodwork 
 immediately adjoining the entrance and gate sills is said to be 
 backed liberally with cement concrete instead of the clay 
 puddle, used so extensively behind the greater portion of the 
 remaining woodwork. 
 
 There are a few leaks visible p round the sides and head of 
 the dock, but not of sufficient extent to cause uneasiness, as 
 far as can be seen by a casual observer. The bottom, how- 
 ever, is so constructed — the floor planks having open joints 
 and hidden ditches below — that a large amount of leakage 
 might occur without tho possibility of detection, except by 
 closely watching the discharge into the pump-well. By 
 measurements taken at this point on the 8th instant, when 
 the clock was empty, dry and to all appearances practically 
 tight, the leakage was ascertained to be at the rate of 965 
 imperial gallons per minute, or 1,389,600 gallons per day. 
 The contractors claim to have stopped some of this leakage 
 since the measurements were taken, but, however this may be, 
 future periodical observations and gaugings taken and record- 
 ed by some competent, reliable and disinterested person, would 
 be instructive and of very considerable interest. 
 
 The works were commenced by the contractors in May, 
 1883, and they hope to complete the whole of their contract 
 early next spring, the principal things requiring attention, 
 now, being the engine, boiler, tools and shafting for the work- 
 shop and some 60,000 cubic yards of dredging. 
 
 The opinion is freely advanced by some of the leading 
 people in St, John's that in view of the completion of the 
 graving dock at that port a structure intended for similar 
 purposes at Halifax is not now needed. A St. John's paper of 
 the 5th instant, however, makes the following remark which, 
 in this connection, is worthy of notice : 
 
 " The great difficulty that we see about making the dock a 
 remunerative investment relates to the fact that for six months 
 
DRY DOCK. 165 
 
 of the maritime year this port is practically closed to ocean- 
 travevsinj^ steamers, and that at the very time of the year 
 when the latter are most exposed to the dangers for which 
 docks are remedies !" 
 
 This statement on the other hand is flatly contradicted by 
 persons who ought to be able to form a correct judgment in 
 such matters ; but, however, this may be, it is a well known 
 fact that the entrance into the port of St. John's, if not actually 
 unapproachable during certain seasons, is at least legar led 
 with no small degree of fear by nautical u.en, throughout the 
 early months of the year, by reason of dense fogs and the risk 
 of encountering large masses of drift ice with which few 
 steamers could safely cope unless built specially for such 
 service. 
 
 It can scarcely be contended thao ^he approaches to this port 
 are open to the same objections, and taking this into cons, ler- 
 ation, and the many other manifest advantages which we 
 possess, besides the fact that the net tonnage of large ocean 
 steamships entering th« harbor of Halifax is over 20 times 
 greater than *St. John's, there can be little room for diversity 
 of opinion as to the advisability of yet constructing a graving 
 dock at this port. 
 
 Regarding wooden docks of the same type as that just com- 
 pleted at St. John's, it must be adraitte<l that so long as they 
 are maintained in a good state of repair they answer all the 
 purposes for which they are intended as well as any other 
 contrivance of a similar nature which could be devised ; ships 
 of any size or class can be deposited in them as readily, safely 
 and cheaply as in docks built of less perishable materials, 
 while the short and narrow altars— which constitute the sides 
 and form a continuous stairway from top to bottom around 
 nearly the whole structure— present the undoubted advantage 
 in winter weather which wood is known to possess over stone 
 or iron in exposed positions. \ 
 
 To claim more than this for the wooden dock it is necessary 
 to assume conditions which cannot be supported by facts, 
 while as a counterbalance there are the grave objections that 
 the structure cannot be regarded as a p ermanent one, and 
 
 *The net tonnage of foreign trading ocean steamships which entered ihe port St. John's 
 in 1882 was 19,504 tons, while at the port of Halifax it was 432,054 tons. 
 
166 WRY DOCK. 
 
 after tho lapse of a few years the repairs account must neoes- 
 sarily be heavy if tlie dock is much used and is kept in per- 
 fect order. 
 
 If the undertaking should be one which owes its existence 
 to large public grants, I venture to think that to most persons 
 who will give the matter fair consideration, these objections 
 must appear fatal to the adoption of wood and clay as the 
 chief materials of construction, unless the circumstances 
 attending the case are such as to assure the subsidizers against 
 the risk of the ultimate loss of their money. 
 
 As legards time required for construction the wooden dock 
 undoubtedly has the advantage. On a favorable site and 
 under ordinary management there is no reason why it could 
 not easily be built within a period of two years, while with 
 every exertion it would not be safe to assume that a stone 
 structure could be completed in less than two years and a 
 half. 
 
 It is claimed for wooden docks that their comparative 
 cheapness should outweigh all other considerations. The 
 American patentee claims that " the original cost is less than 
 one tenth that required for a permanent stone dock," and if 
 this, or even a muih higher value had been fixed as their true 
 worth, there wordd be no need for further argument in their 
 favor. An examination into the facts, however, shows that in 
 some cases at least their actual cost has not fallen short of a 
 fair price for a similar stone structure in a favorable locality. 
 The two wooden docks at Brooklyn are reported as having 
 cost as .'hey stand to-day Sl,283,356 (exclusive of interest) or 
 say $640,000 each — although they are both operated by the 
 same set of pumps — and in the case of St. John's, if thevalue of 
 the lands and the remitted duties be added it will be found 
 that the actual cost of the dock at that port has been about 
 the same sum. A carefully designed permanent stone dock 
 with all its appendages, under similar favorable circumstances 
 and with suitable building materials within a reasonable dis- 
 tance, would not in my judgment prove any more expensive. 
 
 It should also be borne in mind that at this port good 
 building stone for rubble backing and the best of granite for 
 facing purposes are abundant, and by using these materials 
 
DRY DOCK. 167 
 
 our own mechanics and laborers would be employed and 
 benefitted, while by the adoption of wood the bulk of the 
 material needed would of necessity have to be imported. 
 
 If a wooden dock is not often required for use and is 
 kept filled with water when not needed, it is clear that the 
 durability of those portions of the woodwork below tide level 
 will be almost indefinite so 1 ng as they are not subject to 
 attack from " Limnorite" or the " Teredo ;" while on the 
 other hand if the dock is constantly freq uented by shipping . /-- / 
 its length of life must necessarily "be greatly shortened, as 'Ji^liM^^ 
 there is no conditiQn under which the decay of wood is more 
 speedily a b ontunficl than when alternately wet and dry for a 
 fuw days at a time. 
 
 For the above reasons I can see no cause for altering or 
 modifying the opinions expressed in n:y report dated 22nd 
 January, 1883. 
 
 Taking a practical view of the case as it now stands with 
 regard to the proposed dry dock for this port — if it cannot be 
 secured without pecuniary aid from the city — it appeal's to 
 me that while the corporation might reasonably consider their 
 cffitemplated grant of ^10,000 per annum as the utmost which 
 they should contribute towards an undoubtedly permanent 
 structure, it would not seem judicious to subsidize a wooden 
 dock to anything like the same extent, unless the conditions 
 should appear extremely favorable, and satisfactory security is 
 given that the money advanced will be refunded whenever 
 the works fall into decay or cease to be serviceable. 
 
 Respectfully submitted, 
 
 E. H. Keating, M. Inst. C. E., 
 
 Qity Engineer.