992 992 A STUD OOP FRONTAGE Monograph No. 4 Prepared in the Historical Branch, War Plans Division General Staff December, 1919 WASHINGTON GOVERNMENT PRINTING OFFICE 1920 L/t> WAR DEPARTMENT. Document No. 992. Office of The Adjutant General, WAR DEPARTMENT, WASHINGTON, December 19, 1919. The following publication, entitled "A Study in Troop Frontage," prepared in the Historical Branch, War Plans Division, General Staff, is approved and published for the information and guidance of all concerned. [062.1, A. G. O.] BY ORDER OF THE SECRETARY OF WAR: PEYTON C. MARCH, General, Chief of Staf. OFFICIAL: P. C. HARRIS, The Adjutant General. 451439 A STUDY IN TROOP FRONTAGE. 1. Introduction. The war with Germany showed the same essential char- acteristics as previous wars. There is a possibility that J^ 15 - D - 952 the degeneration of the war on the western front into. trench warfare was not inevitable, and that the whole war might have been fought out as an open-warfare p -^ War of problem. However, by the late fall of 1914 the western Positions. AMU. front had stabilized and trench warfare was develop- ing. (1) From this time, the outstanding feature of the war, which continued to be a governing feature during its continuance, was the existence of a continuous western battle front, necessitating frontal attacks. This factor re- stricted the art of maneuver to the massing of troops on various parts of the "front. (2) For this reason a study of the strength in which various parts of the front w T ere held 6) 7> ( or attacked is not only interesting from a historical view- point, but valuable in deducing sound practices for future use. Even an estimation of the number of troops to th yard in battle is attended with considerable difficulty and Troo t to p the a good deal of uncertainty. (3) The documents a vailable cgai Battles sin are so incomplete and liable to error that to base any jg'MJ 74.^0 enera^ general conclusions on facts drawn from the documents Librar y- ( 3 > in individual instances would be dangerous, and might be misleading. There are, at present, available docu- ments sufficiently well authenticated to guarantee obtain- ing approximately correct figures for the practice of the employment of American troops in France. However, it must be realized that even the most reliable documents do not invariably present the facts as they existed. Men get lost or skulk, and are not actually present on the bat- tle line as active riflemen, although they may be carried as present for duty on division returns. As for publica- tions pertaining to armies other than the American Army, they must be viewed with considerable distrust. It was perfectly natural that during the war both French and British military authorities should keep secret the real strength and disposition of forces. As instancing the 5 6 A STUDY IN TEOOP FRONTAGE. o d f difficulty of obtaining facts, it may be noted that the only ! ava ^ a ^ e %ures on the organization of British divisions pl ace the infantry rifle strength at approximately 12,000 'es in Or- rifles in twelve battalions. (4) The only document indi- y dS catin g tnat tn e actual organization had fallen below this ro r pSn SS w2 strength is a cablegram from Gen. Pershing in January, which indicates a contemplated reduction of divisions from twelve to nine battalions. (5) How- biegram ^487, A . e ver ^ '^ j g ft f ac ^ attested to by American officers serving i9i8. H. B. files. w ith the British, that this reduction was actually made by the early spring of 1918, before the German offensive of March 21, 1918, and that even the nine remaining bat- talions were seldom maintained at fuh 1 strength. During the campaign of 1918, when the 27th and 30th Divisions of the Second Corps were considerably under strength, it was estimated that each one of these divisions had an effective rifle strength twice that of the normal British o division with which they were operating. (6) It is, never- , believed that, from a general study of conditions NOV. s, 1919. (6) existing and the disposition of forces taken to meet these conditions, approximate figures can be obtained and val- uable lessons learned. 2. Bases for Computation. In a study involving comparisons in such a large field as the war with Germany offers, a basis of comparison must be immediately established and consistently ad- hered to, in order to avoid confusion in the mind of the student and consequent lack of clearness. For the pur- pose of this study one hundred yards is taken as the front- age unit, and the strength is expressed in the number of Infantry rifles. The choice of hundreds of yards instead of kilometers is unimportant. The yard is our national and tradi- tionally our military unit. It was used throughout the British situa- war by the British. (7) While the A. E. F. in France tion maps D-l. % , . . . Map ^rqorn^ flies, used the French unit as convenient, the units are easily c Report kc.^in convertible. (8) (100 yards equal 91.44 meters, roughly, wed ' NOV.'' 20 1/1 1 o f a kilometer.) The number one hundred in yards yio, pp. ID ana t . / i i -i / 19. (8) is taken to obviate the use of decimals in number of rifles per unit of front. In this connection it should be noted that the width of front given in the following para- graphs is measured from the actual front line as it appears on operation maps. Following in general the eccentric- ities of that line, it may vary therefore very greatly from A STUDY 11$ TROOP FRONTAGE. 7 the width of the zone in which the unit concerned is em- ployed, the width of the zone being normally measured at right angles to the direction of expected attack or resistance. The choice of the Infantry rifle as the unit of strength is not so easily justified. The proportion of tanks, air- planes, special weapons, and above all, artillery, entered largely into the strength in which fronts were held or attacked. (9) However, principal authorities agree on w Feat ures g of *& the supreme importance of the rifle and the fact that rifle 17 -25. (9)^ ' strength is a true index of effective man power. Ac- c E ^ t - E f r c - c cepting rifle strength as an index, it must be consistently J&r NOV.'' 20, arrived at. (10) Here it is taken as Infantry rifles divisions which are in the front line as units and dispose P- 104 - < io ) wholly of their Infantry. The division is the unit uni- versally used in computing strength. (11) It is the Kept, of c. in responsible unit in both attack and defense, (12) com- tied 'NOV.'' 20, bining as it does, all ma] or arms except the Air Service, Th^'war with ,, ,... .-, ... Germany. Ayers, and if employed as a complete division must have at its p. 101. (ii) 11 -r < /i mi T f -n i Instructions on disposition all Infantry rifles. The Infantry rifles only the offensive Ac- are included in computing frontage strength. The regi- units m Battle, ., , . . . -. ji * j_* No. 767, Head- ments of divisional engineers are powerlul organizations, Quarters, A. E. armed with the rifle. They were frequently used as In- 'instructions on , . , , , . .-. the Defensive Ac- fan trV- (13) However, such use is not contemplated in the tion of Large ' J . ,. . . . . -ii Units in Battle. organization of divisions, nor was it invariable or even cus- w. D. D. 794, tomary. (14) The British division had a similar powerful T.'of o., series engineer organization. (15) The French, however, allowed *F. o. 49, 1st , & ,. . . & , , . . . Div., Oct. 8, 1918. the division only the engineers necessary lor purely engi- H. B. 201-13. cm neering work. (16) To include the engineers in .figuring par. p 3, ei k o. 47, frontage strength would complicate, without increasing ibis. H. '.201-13! the value of, the figures arrived at. The American Infantry changes m or- . ' ;, i i i ,1 T / , ganization Found rifle strength as included in the lour Inlantry regiments Necessary during of the division is 13, 568. (17) This includes the auto- pean war. w.c. .., , ' , ' , , ,, , . D. 4886-23. Gen- matic rifle strength, but excludes the machine-gun erai staff college strength. An effort was made throughout to keep di- Tableaux d'Ef- P . - r fectifs, 1913-1918. visions up to strength by replacements, (18) and they can General staucoi- i i i 2. 1 i f n ^i lege Library. (16) be accepted as being at approximately full strength, T. of o series except where otherwise noted. At the beginning of the and 3. (i?) war the British Infantry division, with a total of somec.. e A.' E. "F. . , , _. T cabled Nov. 20, 18,000, was considered to dispose of 11,676 Infantry wis, P. 23. (is) rifles. (19) It is impossible from the facts at hand to Ftrcn P ' during ^ ne war j an d at the time of the American entry in force in 1918 the normal French Infantry division in- cluded 1 Infantry brigade of 3 regiments and had an Infantry rifle strength of 6,880, exclusive of the machine- Tableaux d'Ef- gun companies.. (23) ' The reduction in rifle strength in General staff Coi- the division would naturally be gradual. It was recog- ' 3 nized and accepted as inevitable, however, by the change in organization made in 1916, after great losses had been suffered at Verdun, but before the battle on the statement O fSomme.(24) The strength of Infantry in French In- ch u a"mb r'un!fantry divisions is given by Gen. Pershing in May, 1918, N?! C 14, 1919! as being one-half that of the Infantry strength in an Confidential ca- American division. (25) This would make the Infantry A e E.F"Mayii|rifle strength of a French division from that date ap- proximately 6,750. With the factors of strength and unit of front estab- lished, there remains necessary a classification of various types of front in order to study the strength in which they were held or attacked. In a war which passed from open warfare through the most stilted form of trench fighting and approached absolutely open warfare again in the days preceding the armistice, types run into one, another. The division into four types is there- fore arbitrary. These types are: (a) The quiet front; (6) the active front; (c) the front of a major operation on a stabilized line ; (d) the front in open warfare. This classification is more natural in the character of tne war after the American entry than in the trench warfare which preceded it. However, the last year of the war is the Hept.ofc.inc.. mos t fruitful part for the purposes of this study. From tne German offensive of March 21, 1918, the part played by the man with the rifle on the western front became increasingly important. (26) In spite of the immense number of participants and casualties at Verdun and on History of the the Somme, these operations were in principle a conflict monds. \ a oi. iii,' of material resources, artillery, ammunition and trench mechanisms and were not essentially based on the rifle strength per yard. (2 7) A STUDY IN TROOP FRONTAGE. (a) A quiet front is taken as one on which the char- acter of the ground or the disposition, of forces renders it unlikely that a major operation will develop. (I) An active front is taken as one on which actiA T e major opera- tions have recently occurred, or on which they can be expected soon to occur, (c) The front of a major operation on a stabilized line is one on which a major operation on such a line is actually in progress and is restricted to the center of attack or defense in which participation is complete, (d) The front in open warfare is one on which action is concerned with an enemy in the open and not with a continuous line held by or against the enemy. 3. General Discussion of Formations. Before citing instances from which to draw frontage strength, it is interesting to note in general formations adopted in attack and in defense and in particular those adopted by American divisions. It must not, however, be forgotten that whatever the formation, a division must be considered to engage on its front its entire rifle strength present within the division. The French formation for attack in 1914 may bo London accepted as not abnormal. Briefly, it employed depth war. "vol. i, p. with only the necessary troops deployed. (28) On the defensive an attempt to preserve depth was evident in the organization of positions into trench systems in the earlier years of trench warfare. An even distribution in depth, however, was sacrificed to the desirability of utilizing the shelter afford ed by trenches for the protec- tion of all troops. This tended toward a dense occupation The war of PO- of trenches which was emphasized at points of tactical ss'S^eq.lS?' * importance. (29) These methods proved too costly at History of the Verdun and on the Somme,(30) and were abandoned inmonds. VOL ILL favor of very deep formations to conserve man po and to give elasticity to the defense. In attack, depth instruction OB A.' i i , i /- \ -XT- -, the Offensive Use lormations were habitual. (3 1 ) JN o authenticated instance of Large units m is known of deliberate use of mass formations. Periodic Hq. A. E! .F^ reports in the press of all nations of enemy attacks in ^instructions on mass probably record honest delusions. The impression of Large n units S of power received on the front of a battalion advancing 794, lois. (3i)' in an attack maneuver is tremendous, even though the battalion be organized more than 600 yards in depth. The human mind in such cases tends to associate mass with power. 155880 20 2 10 A STUDY IN TROOP FRONTAGE. A depth formation was habitually used by American divisions. The exact formation, however, depended on the physical and military aspect of the front and the DI> Jufy' ^established practice in the division in question. One i3 18 '(s^' B * 201 ~ experienced division held or attacked with brigades DIV sept 7 ' IQ abreast, regiments abreast, battalions in depth, as a W F" o 35, 2d norma l formation. (32) Another varied its formations H. V B'.m (33) 918 * and sometimes attacked with brigades in depth. (33) At times on very quiet fronts divisions were compelled to hold with reduced depth. 4. American Occupation of a Quiet Front. faSShe a d G i?cf On A u g ust 19, 1918, the 5th Division held a front of i9 r5t i9?8 iv ' J li 1 a g ' a ^ out 325 hundred yards in the St. Die Sector. (34) >m r fll ( es 4) major offensive was imminently expected on this front, and the Artillery preparation for the German offensive from Montdidier to Noyon on June 9, 1918, actually included this front. On August 16, 1918, the 3d Corps held a front of official map of about 120 hundred yards at Fismes on the Vesle. It Aug. C IG, ?9is. had in line the 28th and 77th Divisions(48) with ano-3,A.E.F. Infantry rifle strength of approximately 2 1,000. (4 9) Army Corps, Aug. The frontage strength per hundred yards would there- iss-2. (48) fore be about 175 Infantry rifles. The advance to the Div. Returns for Vesle had just been completed and this front was held isis. a Fiies ug of J .,, . , ,. . ' A. G. 0.(49) against possible strong reaction and preliminary to an Rept. of c. in offensive from the Vesle. (50) bfed ' NOV. '' 20, On September 21, 1918, the 78th Division held a front 19 of about 76 hundred yards northeast of Thiaucourt. (51) The Tactical Its Infantry rifle strength on this date was about 12,300. ?8thp^A.E. t F.! (52) The frontage strength per hundred yards would M * c.; sejS be about 162 Infantry rifles. The division had relieved $?J 9 !Sn H ' B - 12 A STUDY IN TROOP FRONTAGE. 2d and 5th Divisions after the St. Mihiel opera- and was holding the front against possible strong * 52) reaction. The average frontage strength per hundred yards in the instances given, covering four divisions, was 171 Infan- try rifles. This can be accepted as approximating the normal. There were not many cases of the occupation of an active front by American divisions except when engaged in major operations. 6. American Participation in a Major Operation. On July 18, 1918, the 1st Division attacked on a front Div'., ju?y* il!f about 29 hundred yards south of Soissons.(53) Its (53)" H - B - 201 ~ 13 - Infantry rifle strength on this date was approximately turns ?o7' June 13, 500. (54) The frontage strength per hundred yards nils S A! G. 9 o: would be about 465 Infantry rifles. On September 12, 1918, the 5th Division attacked on F. o. 41, sth a front of about 25 hundred yards in the St. Mihiel oper- KIS^H.' B. P 2ofcatioii.(55) Its Infantry rifle strength on this date 5 ' Weekly Graph- was approximately 12, 900. (56) The frontage strength Bcpt? f ?5Ti9i8! P er hundred yards would be about 516 Infantry rifles. F sk S eiSxm A * E 5tii It should be noted here that this is the greatest strength G-3'flies,"A^. r F'. that will appear in this study. The following condi- tions appear to have produced it: The division was attacking through comparatively open ground in the center of the main attack of the First Army. This explains why its strength per unit of front is the maxi- mum in the Army, approximately equaled by the 2d and 42d Divisions, which attacked under similar circum- stances, but greater than that of the 89th, also a center ^Official map^of division, but facing a solid mass of woods, where prog- mIs"G-3 a \ EF lress snou ld be slower and the need of original impulse f e Srm? f C '& conse 12 ' troop movement, supply, and communication. (69) 8. General Discussion of French and British Practices. It would be misleading to attempt to compute French and British practices from specific instances. Docu- ments giving such instances are generally only available owing to association of our units with foreign units, and are too infrequently available to warrant drawing gen- eral conclusions and data therefrom. General state- ments as to practices are found in studies on the number of troops to the yard in principal battles during the last half of the nineteenth century and deductions drawn Memorandum therefrom by foreign authorities. (70) These practices Troops^o 1 the are more or less confirmed, and at any rate brought up to cipai Battles siilce date, in instructions issued by French and British mili- staff ' College 6 Li- tary authorities toward the end of the war with Germany, which give the desirable practices in certain instances. (71) the Defensive A C - The specific instances given below are only of value as tion of Large , . ... , . j / i units in Battle, showing a tendency to maintain the attacking or defend- W D D 794 1918. ' 'ing strength prescribed in the instruction pamphlets, as The Division in , -, i c ,1 T, Attack, ss- 135, determined by the general experiences of the French Nov.. 1918. Gen- , ^ . , . , J . TT erai staff College and British armies on the western front. Very general rary ' and valuable information is afforded by copies of French Allied Order of Battle Maps, but information as to actual British occupations is less satisfactory. 9. French and British Occupation of a Quiet Front. On June 25, 1916, the French Group of Armies of the East held a front of about 2,900 hundred yards from St. oS??ai oSe? c ?fMihiel to the Swiss border, with 18 divisions in line. (72) 25* ap i9iNo exact data as to the strength of these divisions are 72) available. Divisional strengths varied considerably. This was about the time of the change in organization of A STUDY IN TROOP FRONTAGE. 15 French divisions. (73) The strength is therefore taken 6,880 Infantry rifles per division, the full strength in the * n * J 1 b 1 new organization. The strength of the 18 divisions would Nov - 14 > 1918 - < 73 > be about 143,840 Infantry rifles. The frontage strength per hundred yards would be about 49 Infantry rifles. On October 13, 1918, the same Group of Armies held a front of about 2, 100 hundred yards from Nomeny to the Swiss border, with 12 French and 3 American, or the equivalent of 18 French divisions, in line. (74) At oS divisional strengths given in Gen. Pershing's cablegram ilf tl i9i8? p ' Sap of May 1 1, 1918, the rifle strength would be about 121,500. Tf. F?(?4) G " 3 ' The frontage strength per hundred yards would be 58 Infantry rifles. The average for the two cases cited would be 54 Infantry rifles per hundred yards. This does not vary too much from cases of exceptional extension in preced- ing wars, which have fallen as low as 80 Infantry rifles per hundred yards for defending troops. (75) Nor does the French figure materially differ from that of American ySSfSi the divisions on similar fronts, which has been seen to be Se i85o. at Gen- about 64 Infantry rifles per hundred yards. On November 11, 1917, the British Third Army held a front of about 600 hundred yards in front of Cambrai, with 1 1 divisions in line. (76) No exact figures on the strength o gpy of these divisions are available. Before Gen. Byng'sgattie ^ tank attack the Cambrai front was regarded as being Map' rooin^ files as quiet a sector as any in the British zone, and the< 76 )' map shows that it was lightly held in comparison to the rest of the British front. The holding divisions can therefore be taken as depleted to a rifle strength of about 9,000 each or the average for the early spring of 1918. The Army rifle strength would be about 99,000. The frontage strength per hundred yards would be about 165 Infantry rifles. It will be noted that this is a much larger figure than that found in the case of American and French occupations. The discrepancy is probably explained by the fact that on no part of the British front were, major operations so unlikely, on account of difficulties of terrain, as in the Vosges Sector, from which American and French instances have been taken. 10. French and British Occupation of an Active Front. On August 23, 1916, the French Second Army held a oSS or F d e e r nC o h f front of about 850 hundred yards around Verdun, with 17 divisions in line. (77) It has been seen that French 16 A STUDY IN TROOP FRONTAGE. divisions had recently been reduced to three Infantry regiments; the full strength of the new organization is therefore taken, or 6,880 Infantry rifles. This gives a total for the Army of about 1 16,960 Infantry rifles. The frontage strength per hundred yards would be about 137 Infantry rifles, which can bo accepted as not abnormal. On the date in question the German assault had been History of the worn out (78) and the front may be considered as merely in" veI T active. Despite the statement in French instruc- tions that divisional fronts depend on varying conditions, and that there is no average or theoretical front, French military authorities give an approximate front for a divi- sion engaged in actual defensive battle in 1918 as from instructions on 22 to 44 hundred yards. (79) Assuming that the lesser ity may be taken, on a front where battle is merely expected, the frontage strength per hundred yards would be 153 Infantry rifles. This agrees nearly enough to con- firm, as of value, the factor of 137 found in the case of the French Second Army. Map of Mar. IT, ^ n March 17,1918, the British Third Army held a front ' about 430 hundred yards in the vicinity of Arras, with divisions in line. (80) It has been seen that before this date British divisions were reduced to 9 battalions. The strength of the 10 divisions would therefore be 90,000 Infantry rifles at the maximum. The frontage strength per hundred yards would be 210 Infantry rifles at the maximum. 11. French and British Participation in a Major Operation. oS^^riGTS On August 10, 1918, the French First Army was at- 5?g tle w ap ms tacking, in conjunction with the attack of the British ' (lif Fourth Army, on a front of about 300 hundred yards in the vicinity of Montdidier. It had 10 divisions in tho front line, (81) which at the strength which has been accepted from May, 1918, give a rifle strength of about 67,500. The frontage strength per hundred yards would be 227 Infantry rifles. It wiji be noted that despite the fact that this attack was one of the most successful of the war, the frontage strength is very much smaller than that determined for individual American divisions in similar attacks, such as that of the 5th Division at St. Mihiel. However, the density is naturally reduced in figuring from the large front and strength of an army, by the inclusion of divi- sions on the flank of the attack which may not be actually A STUDY TN TROOP FRONTAGE. 17 assaulting on the day in question, and consequently are in lesser density. It will be remembered that while the frontage strength of the 5th Division at St. Mihiel was 516 Infantry rifles, the frontage strength computed for the whole southern attack was only 235 Infantry rifles per hundred yards. The French figure approaches; how- ever, the maximum density of 306 Infantry rifles per hundred yards for a division engaged in defensive battle, obtained from the French instructions cited in the pre- ceding numbered paragraph. The maximum density under such circumstances may be accepted as approxi- mately the proper density for a division on favorable ground in the center of a major offensive. An example 'of what may be considered the greatest density desirable under the circumstances may be obtained from the following incident: Gen. Petain gave Gen. Fayolle, commanding the Group of Armies of the Reserve, 12 divisions for the attack of July 18, 1918, south of Soissons. Later Gen. Petain asked if one of these divisions could be spared. Gen. Fayolle answered that it could, as his original plan had called for one division to attack in the valley of the Aisne, but that it was not vital to attack on this part of the front. (82) It may be assumed that had Gen. Fayolle statement wished greater density on the front on which he actually cha' attacked, he would have used this division to attain it. Nov The frontage strength per hundred yards of front for the 1st Division in this attack has been seen to have been 465 Infantry rifles. The French divisions, weaker in Infantry rifles, attacked on a narrower front. (83) The statement of density found for the 1st Division can therefore bechambr'un, ,1,1 i.i* , French Army, accepted as approximately the maximum desirable under NOV. u, i9is. (83) the circumstances in the opinion of the French high command. On August 10, 1918, the British Fourth Army was copy of French , . t m i Official Order of attacking on a iront of about 370 hundred yards east of Battle Map, Aug. * T . T T -r, . . T A ,. . . 10, 1918. Map Amiens. It had 9 British and 1 American divisions in room files 0-3, line. (84) The American division can be taken at approximately full strength, or 13,500 Infantry rifles. If the British divisions be taken as approximately one- half of this, on the authority given above, the Army would have in line 74,250 Infantry rifles. The frontage strength per hundred yards would be about 200 Infantry rifles. The same remarks as to the success of the operation and as to density made in the case of the French First Army 18 A STUDY IN TROOP FRONTAGE. engaged in the same attack apply here. However, the frontage strength found for the British Fourth Army approaches the figure of best practices given in British military instructions in 1918. These give a frontage strength as varying from 100 men per hundred yards of front upward for a division in the attack, but state that -?35 n a smaller density than 300 to 500 per hundred yards will cS 1 ) rarely prove successful. (85) The frontage strengths so far developed in the study of major operations during the war with Germany are considerably less than those given by the best authorities before the war with Germany as desirable strengths for attack. (86) It is evident that this was not caused by on Me Number U ofthe shortage of men on such a large front, as there is a YarS p in the Prin- general agreement between American, British, and S! B (fel S e S ?a e ! French authorities, fixing the density desk-able in an Library? (86) ese attack as about 300 to 500 men per hundred yards. The smaller density found desirable in this last war is probably the direct result of the highly developed power of modern artillery and machine guns. 12. French and British Participation in Open Warfare. On September 27, 1914, the French forces were de- ployed on a front of about 5,400 hundred yards. This excludes a small front held by the British Expeditionary Corps. The French occupation extended from Douai Offic?JioS?r nc ?f to about 80 kilometers north of the Swiss border, and se a pt! e 2^191! incul(1 ed about 43 divisions in line. (87) The average Map A r 000 P er division. It may have been less. (88) At Frenei? 1 b Army' ^ ne maximum there is obtained the frontage strength per NOV. i4, wig. (8sJ hundred yards of 95 Infantry rifles. Not only is this figure obtained from very incomplete data, it mani- festly does not even represent the strength in which the portions of the front actually were held. The map shows frequent large gaps between units. The figure is, however, of value as confirming the inevitability shown in American instances of employing in open war- fare a less density per unit of front along the whole front of operations than in major operations on the stabilized line. A study of modern warfare previous to the war with t 6 - Germany, with the fighting on a stabilized line that it eveloped, shows frontage strengths very much larger ege than those found for American and French units. The A STUDY IN TROOP FRONTAGE. 19 strengths in previous wars are, however, figured merely from the front on which battle was actually engaged, without considering at all the rest of the field of operations. (89) In spite, therefore, of the apparent density of troops in previous modern wars, it appears that a maxi- mum density on large fronts was developed in the great attacks of the war with Germany. The experience of the British Expeditionary Corps in 1914 was too chaotic and changing even to attempt to draw therefrom any British frontage strength in open warfare. The British forces naturally had the same ex- perience in semi-open warfare in the days preceding the armistice as did the American Expeditionary Forces. On November 10, 1918, the British First and Third Armies, with 14 divisions in line, were advancing on a front of about 715 hundred yards in the region of Mons. (90) At a divisional rifle strength of about 6,000, the frontage g strength per hundred yards would be about 120 Infantry Q-a, A.E.F. (90) rifles. 13. Conclusions. Conclusions drawn from this study are summarized in a table which follows. It must be consulted, however, with these facts in mind: In an effort to give a simple tabulation round numbers only have been employed. In cases where a statement of best practices has been found, that statement has been adopted rather than figures drawn from isolated instances. The frontage strengths in open warfare are figured on the entire front of the operation. The very name "open warfare" indicates the condition that exists. Troops operate as units, with open spaces between them. The frontage strength of a divi- sion or smaller unit would therefore be much denser if figured on the front physically occupied by that unit. So figured, it would depend on the formation adopted. This formation might very well approximate and give the same frontage strength as the formation of a division or smaller unit in a major operation on a stabilized front. The considerations which dictate both formations are the same the necessity for obtaining maximum power and the desirability of minimizing losses. 20 A STUDY IN TROOP FRONTAGE. Best practices in the number of Infantry rifles employed per hundred yards of front. [In round numbers.] American. French. British. Quiet front 60 50 160 Active front 170 150 210 Major operation 400 310 400 Open warfare 90 90 r^o from 6 tiSj 6 World 14. Proportion of Divisional, Corps, and Army Troops to Infantry Rifles. For the purposes of this study the unit of strength has been taken as the number of Infantry rifles in front line divisions. The number of Infantry rifles for a unit of front under varying conditions has been determined. Consideration of other divisional troops and corps and army troops has been omitted in order to clarify this dis- cussion. With the basic figures established, however, a consideration of the proper proportion of other divisional troops and of corps and army troops is interesting. organization can cover all the possible c'ontin- W g-Loringhoven," gencies of modern war. (91) The great war abundantly proved this. To attempt to deduce proper proportions from prewar European organization and the changes made would be bewildering. Fortunately there exists a statement of best practices in the organization of a field army with Service of Supply troops in the Priority Schedule prepared at General Headquarters, A. E. F. This is supplemented by Tables of Organization, 1918, sufficiently to determine* proportions without reference to the million and one varying instances which might be selected from the war experience of American, French, and British troops. Report of c. in The two documents cited above were prepared after bied ' NOV. *' 20, a thorough consideration of allied organization and ex- perience after years cf war. (92) They may therefore confidential ca fiw^fy.^ 6 assumed to represent a composition of the best A le E F' A 8 r 7 9' practices of allied armies. The Priority Schedule was 1918. (93)' ' no t completely followed as drawn up, owing principally Report of com- to the urgent necessity for shipment of Infantry and ^i?^r g A e r n my;rnachine-gun units to meet the emergencies of the spring 128-129, F ifc-S; of 1918. (93) The essential soundness of division and corps organization was proved in the experience of the First American Army. (94) A STUDY IN TROOP FRONTAGE. 21 It should be noted that aviation units were not figured in the Priority Schedule. Aviation was given a separate schedule without regard for maintaining a Letter from c properly balanced army in an effort to lend most rapid g^ ^ 17 E H^' assistance to the allied cause. (95) As it was omitted 45 ~ 7 -^ 5 ) from the proportions arrived at by Gen. Pershing, it may be omitted in arriving at the proper proportions desired for this study, merely bearing in mind that an inclusion of aviation would increase the proportion of corps, army, and S. O. S. troops. Another point which must be considered is the inclu- B?T&ieibi,iSS. sion of replacement divisions in S. O. S. troops. While (9( originally included in the organization of corps, (96) Report of c. in replacement divisions actually seldom functioned as such tied ' NOV.*' 20, . , . ,, j. ,, 1918, pp. 17 and 23. within the corps, and replacements were drawn from the (97) general reservoir of newly arrived divisions. (9 7) Best Report of c. in authorities give the proper basis for number of divisions bied A * NOV!"*' 20" actually functioning within a corps as four, two in line M Be^rt'ofC.G., and two in reserve. (98) Eeplacement divisions are con- fsl-iss^^s)' pp * sequently figured in S. O. S. totals. A third question to be decided is the number of corps Report of c. G.. in an army which would normally be in line. The First io2et seq n f99) pp ' Army generally employed four corps in the attack in the Meuse-Argonne battle, three west of the river, one east. (99) While other corps in the First Army were under the circumstances actually employed in line, the Army commander in his report insists on the necessity of a corps in reserve. (100) While the ideal corps in this report is described as without permanently assigned divisions id., pp. 132-133. (101), there were always divisions in Army reserve which could have been administered by such a corps. The fifth corps included in the Priority Schedule is therefore considered as being, with its combat divisions, in Army reserve. The number of Infantry rifles in a division is 13,568; T. of o., series the total number of officers and men is 28,172. (102) For and 3. ('102) the purposes of the Priority Schedule, however, the divi- p ri0 rity sched- sion was taken at 27,063. (103) In order to tie the num-^E G f., p file f: ber of rifles into the Priority Schedule, the latter figure is (103) used in obtaining proportions. The number of Infantry rifles is 50 per cent of the strength of the division. The number of Infantry rifles on the front of. a typical corps with two divisions in line is 27,136. The total 22 A STUDY IN TROOP FRONTAGE. number of officers and men in the typical corps is 177,070 ; less 2 replacement divisions, it is 122,944. (104) The number of Infantry rifles on the corps front is therefore 22 per cent of the corps strength in the corps sector. The number of Infantry rifles on the front of a typical army with four corps in line, each with 2 divisions in line, is 108,544. The total number of officers and men in the typical army of five typical corps, plus army troops, is 685,214. The number of Infantry rifles on the army front is therefore 16 per cent of the army strength. It is 9 per cent of the strength of the army and the necessary id., summary. S. O. S. troops for its supply, including replacement divisions. (105) STATEMENT OF WORKS, DOCUMENTS, AND PERSONS CON- SULTED (IN ORDER OF CITATION). Features of the War. Haig. W. D. D. 952 ,1919. Deductions from the World War. Von Freytag-Loringhoven. The War of Positions. Azan. Memorandum on Number of Troops to the Yard in the Principal Battles since 1850. U 167-G 74. General Staff College Library. Strength and Organization of the Armies of France, etc. W. D. D. 22, 1916. Changes in Organization Found Necessary during the Progress of the European War. W.C.D. 4886-23, 1915. Confidential Cablegrams, A. E. F. , 1917-18. Brig. Gen. George Simonds, Chief of Staff, 2d Corps. British Situation Maps, map room files G-3, A. E. F. Report of C. in C., A. E. F., cabled Nov. 20, 1918. The War with Germany. Ayers. Instructions on the Offensive Action of Large Units in Battle. No. 767, Headquarters, A. E. F., 1918. (Translation from French document.) Instructions on the Defensive Action of Large Units in Battle. W. D. D. 794, 1918. (Translation from French document.) Tables of Organization, Series A and B, 1918. Field Orders, 1st Division, Historical Branch,, file 201. Tableaux d'Effectifs. U. A. 702-A 39 (1913-18). General Staff College Library. London Times History of the War. Lieut. Col. de Chambrun, French Army, attached to Gen. Pershing's Staff. History of the World War. Simonds. Field Orders, 2d Division, Historical Branch, file 202. Divisional Maps, map room files G-3, A. E. F. Divisional Returns, files A. G. O. Maps of American Fronts, map room files G-3, A. E. F. Field Orders, 3d Army Corps, Historical Branch, file 183-2. The Tactical Operations of the 78th Division, Historical Branch, file 278. Weekly Graphics of Personnel, files G-l, A. E. F. Field Orders, 5th Division, Historical Branch, file 205. Skeleton 5th Division History, files G-3, A. E. F. Report of Commanding General, First Army, files G-3, A. E. F. Second Army Corps Instructions, Historical Branch, files 182. The Division in Attack, SS-135, Nov., 1918. General Staff College Library. Copies of French Official Order of Battle Maps, map room files G-3, A. E. F. Combined Order of Battle Maps, map room files, G-3, A. E. F. Letter from C. in C., A. E. F., Oct. 7, 1917. Historical Branch, file 45-7. Priority Schedule, files G-3, A. E. F. 23 O Gay lord Bros. Makers Syracuse, N. V. ' PAL JAN. 21 ,1908 YC 6,4444 5 1439 UNIVERSITY OF CALIFORNIA LIBRARY