Re-examining the History of Chemical Warfare Part II

Georg Bruchmuller and the Chemical War

American unpreparedness for the First World War is the overall narrative for its entire war effort.[1] Chemical warfare is just one aspect of that broader problem. The American Army suffered numerous issues related to equipment, discipline, and training that affected its response to the chemical battlefield of 1918. As Tim Cook argued in his work on the Canadian response to chemical warfare, the key to success was “gas discipline,” the individual and small unit collective tasks necessary to protect troops from the effects of chemical weapons and carry out operations in contaminated environments.[2] It is not surprising that the more experienced Allies and Central Powers generally performed better in this regard than the Americans. For almost a century, it has been a truism that the Americans suffered a higher percentage of chemical casualties than the British or French in 1918, in large part due to this aspect.[3] Yet, the true picture of 1918 is significantly more complicated and challenges this traditional narrative.  

The first problem is numerical. Almost a third of total AEF casualties were the result of exposure to chemical agent.[4] Comparing the American experience in 1918 to the British, French, or German experience over the entire war is an apple and oranges comparison. The vast majority of all chemical casualties on the Western Front occurred in 1918.[5] The other combatants suffered similar percentages to the AEF in 1918, especially during major battles.[6] Calculating British and French chemical casualty data for 1915-1918 produces dramatically lower numbers that obscure this fact. The first three weeks of German mustard agent produced as many chemical casualties on the Western Front as the previous three years combined.[7] During major battles in late 1917 and in 1918 French and British casualty rates from chemical weapons varied depending on the amount of agent used by the Germans.[8] In the Spring Offensives, the French chemical casualty rate was just under forty percent.[9]  In major battles during 1918, French and British chemical casualty rates were equivalent to or exceeded American averages.[10]  In fact, casualty rates were roughly proportional to the amount of agent used, and most of those casualties were due to mustard. 

It was not until the Germans started running out of shell in the final weeks of the war that the Allied gas casualty rate declined significantly.[11] American inexperience and lack of gas discipline is not nearly as explanatory as later implied. Even the most inexperienced unit in the AEF to engage in combat, the 79th Division, appears to have suffered no worse a casualty rate than neighboring French units, though the accuracy of the numbers is problematic.[12] In 1917 and 1918, Britain and France also fielded many ill-trained and poorly equipped troops. This and the fact that chemical warfare was rapidly changing meant all the Allies struggled with chemical defense in 1918. It is not enough to say that chemical casualties and deaths as a percentage of total casualties was insignificant. While that is a true statement when discussing the war in its entirety, it ignores the nature of the war in 1918, when the statement is demonstrably false if applied only to that year. Chemical casualties were a big deal in 1918, especially for the Allies. Saying chemical warfare in World War I was insignificant due to casualty statistics is like discounting the number of nuclear weapon casualties in World War II, since they too were a small portion of the total. 

This is lost on most historians of the war. In part, this is due to a fundamental misunderstanding of how both sides fought in 1918. The German Spring Offensives, also known as the Ludendorff Offensive, represented a dramatic change in the war and a key component of that change was chemical. Two key developments occurred in 1917, the first technological, the second tactical. First, in July, the Germans introduced mustard to the battlefield for the first time at Ypres. In September, the Germans used mustard, along with others, at Riga on the Eastern Front. The attack at Riga incorporated these chemical weapons into new tactics, known as “Hutier tactics,” so named for Oskar von Hutier, the German General who pioneered their use. These tactics are most often associated with German Stoßtruppen.[13] Yet those troops were only part of the innovation.

The most significant innovation of Hutier tactics were new artillery techniques developed by Georg Bruchmüller, dubbed  Herr Durchbruchmüller (Breakthrough Müller) by his troops. Bruchmüller authored his own post-war treatise in 1922 recounting his tactical innovations, Deutsche Artillerie in den Durchbruch schlachten des Weltkrieges (German Artillery in the Breakthrough Battles of the World War). Key to the new artillery tactics were innovative uses of gas warfare.[14] Bruchmüller also employed new targeting methods and the use of a creeping barrage to provide cover for assault troops, led by the infiltrating Stoßtruppen, who bypassed strongpoints, disrupting the ability of allies to counter attack.

Georg Bruchmuller. Public Domain

Prior to Bruchmüller, most gas attacks utilized cylinders or artillery barrages of gas across a wide front. The gas quickly dissipated and attacking troops followed. The major German technical innovation of 1917 was the development of mustard shells.[15] Unlike previous agents, mustard agents were persistent agents that contaminated the ground and anything the oily liquid landed on, for weeks and even months.[16]  Both sides hit on this new property of persistence realizing its usefulness as a method of terrain denial. Bruchmüller used it to seal the flanks of German penetration attacks from counter-attack, while hitting the front with a large combination of Blue and Green Cross shell designed to first penetrate Allied mask filters with arsine based compounds and then produce casualties in front line troops with pulmonary agents.[17] Gas shelling increasingly used a mixture of high explosive and chemical rounds, so much so that casualty numbers began to blur, especially with the introduction of German high explosive mustard rounds where the contamination was a secondary effect.[18] 

Bruchmüller pioneered the use of chemical agents against artillery positions in rear areas to disrupt the counter-battery fires that broke up previous assaults. Artillery in 1918 was more accurate than 1914, but not nearly effective enough to reliably strike artillery targets to the rear of the front beyond the line of sight. It could however, disrupt concentrations of assaulting troops in the open. Chemical weapons were much more effective against artillery than high explosive. Chemical shells had only to strike nearby and in high enough concentration to force gun crews to shelter or put on protective equipment. Some agents even had corrosive effects on the guns themselves. Chemical weapons became critical to knocking out enemy artillery in 1918. Bruchmüller also used gas at key road junctions to the enemy rear, disrupting reinforcements. Similarly, he used chemical shell to deny terrain like wooded areas, bypassed high ground, or other areas where troops might shelter or pose problematic for attacking troops. While the death rates from gas fell continually during the war, owing to improvements in gas discipline and defenses like masks and gas-proof dugouts, the casualty rates actually increased in 1917 and 1918, especially with the introduction of mustard agent.[19] Important in a war of attrition, chemical warfare tied up significant resources in manpower, medical, decontamination, and supply.

The escalation of chemical warfare on the Western Front came at a critical moment in the war. The Allied offensives of 1917 were disastrous. Both the French and British armies nearly broke, with mutinies in some units. Only the entry of the United States into the war offered a boost to Allied moral. As the final 1917 offensives sunk into the mud of Passchendaele, the Allies looked forward to a defensive year of rebuilding, in preparation for a final offensive in 1919. The new American forces were vital to that plan, after significant time spent raising, deploying, and training America’s hastily assembled and ill-equipped force. The Germans knew the Americans posed a threat if allowed to mobilize and deploy sufficient forces, but those forces would not be ready to fight until late in 1918. The German Supreme Command, under the direction of General Paul von Hindenburg and General Erich Ludendorff, decided for one final push before the Americans came on line. The German Spring Offensives were actually several separate operations between 21 March and May of 1918. Most of the German success came in the first sixteen days, when the Germans penetrated Allied lines to a depth of 60 kilometers, capturing 1,200 square miles of territory.[20] Ludendorff said later, “It was a brilliant feat of arms and will always stand as such in the history of the world. What the English and the French had not succeeded in, we had accomplished, and in the fourth year of the war.”[21] Yet, the attack did not lead to victory. Major General David Zabecki, writing on the subject, explained the German failure by suggesting the German Army and Ludendorff were “tactically gifted, operationally flawed, and strategically bankrupt.”[22] The reasons are open to debate. Usually left out of the debate is the role chemical weapons played in that tactical success, and how they sustained the war after.

On March 21, 1918, near Saint-Quentin, the Germans fired over three million shells, both gas and explosive. The shelling was so intense London awoke to the sound. The chemical deluge was concentrated and equally excessive. Witnesses reported the gutters of Armentiéres ran with mustard “like rain,” during three-days of near continuous shelling.[23] The initial bombardment was the largest artillery bombardment in history, and the largest chemical attack. Traditional narratives often miss that one third of the shells in the initial barrage were chemical shell. Mustard produced almost 12,000 Allied casualties on the first day, and the blue/green shells contributed an additional 3,000.[24] The breakthrough expanded quickly, and by March 26, a semblance of open warfare returned to the Western Front. Chemical warfare proved essential to the initial penetration. Mustard shells pried open the lines.  

Map from William G. Macpherson,, W. P. Herringham, Thomas R. Elliott, and Andrew Balfour, Medical Services; Diseases of the War, Volume II – Including the Medical Aspects of Aviation and Gas Warfare and the Gas Poisoning in Tanks and Mines (London: H. M. Stationery Office, 1923).

Next time we'll examine this new chemical war in the final months of World War I and take a closer look at the American experience. Please check back with for more!

[1] For an examination of this dysfunction, see Paul F. Braim, The Test of Battle: The American Expeditionary Forces in the Meuse-Argonne Campaign (Newark: University of Delaware Press, 1987). Note that Braim softened his critique of the AEF significantly in the second edition of this work.

[2] Cook, 212-238.

[3] Amos Fries, the post-war head of the U.S. Chemical Warfare Service and chief chemical officer in the AEF during the war, repeatedly acknowledged this disparity in casualties in his official history of the AEF Chemical Service, Congressional testimony, and his book on chemical warfare.

[4] The sources do not all agree on the exact figure, but the approximation used here is within the range. The AEF officially put the number at 27 percent in some sources, but other examinations put the number over 30 percent. See Spiers, 39; Heller, 88-91; Prentiss 1937, 653.

[5] The highest chemical casualties on the Eastern Front occurred in 1917. 

[6] A note of caution exists with all these numbers. Approximations are useful, but only when being very specific about what is approximated. On the average, gas casualties were understated in early attacks and large-scale attacks where units suffered decimating losses or were overrun. During and after the Spring Offensives, the trend is to overstate the numbers due to large numbers of “worried well” and shirkers/malingerers, especially in inexperienced units. Over time medical officers became adept at weeding these out, and casualty numbers tended to fall somewhat. There are also discrepancies between figures reported at the battalion and regimental level and division and corps numbers. The higher-level numbers, which typically drew on hospital and medical data not available to the front line units, are probably more accurate as they were verified casualties, not merely those evacuated. These numbers may understate things, however, as those quickly returned to duty with low-level doses or those with both gas and projectile injuries may not be included. 

[7] Gilchrist; Oliver Lepick, La Grand Guerre Chimique: 1914-1918 (Paris: Presses Universitaires de France, 1998), 314-321; Augustin M. Prentiss, Chemicals in War: A Treatise on Chemical Warfare (New York: McGraw Hill Book Company Inc., 1937), 649-676.

[8] Lepick 314-321; Prentiss, 649-676.

[9] Ibid.

[10] Lepick 314-321; Prentiss, 649-676.

[11] Spiers, 38-39.

[12] Rexmond Cochrane, US Army Chemical Corps Historical Studies, Gas Warfare in World War I, The 79th Division at Montfaucon, October 1918 (Washington, DC: U.S. Army Chemical Corps Historical Office, August 1960), 56-57. Cochrane compared the reports compiled by the 79th Division Gas Officer with the French records of II Corps. Significant discrepancies existed between battalion and regimental reports and the reports at Division in both the AEF and the French forces. The reasons are numerous and could form the basis of another article, though in general terms it likely came down to alternate sources of information at each level, and issues with some of the sources from which Cochrane was drawing numbers, specifically post war divisional and unit histories which were inconsistent with frequently incomplete unit records. The original 79th Division Gas Officer reports are available via the Combined Arms Research Library (CARL) – Digital Library  at Fort Leavenworth, Kansas at (accessed November 26, 2014).

[13] These infiltration/assault troops sometimes appear as “Sturmtruppen” or Stormtroops. For a full examination see Bruce I. Gudmundsson, Stormtroop Tactics: Innovation in the German Army, 1914-1918 (New York: Praeger, 1989); and Timothy T. Lupfer, Leavenworth Papers No. 4, The Dynamics of Doctrine: The Changes in German Tactical Doctrine During the First World War (Fort Leavenworth, Kansas: U.S. Army Command and General Staff College, 1981).

[14] Georg Bruchmüller, Deutsche Artillerie in den Durchbruch schlachten des Weltkriege (Ann Arbor, MI: University of Michigan Library, 1922).

[15] The German shell marking for mustard led to its nomenclature as “Yellow Cross.” The Allies referred to the new agent as “Yperite” in honor of where they first encountered it.

[16] While typically called “mustard” or incorrectly “mustard gas,” the actual agent can vary depending on the process used to produce it. No matter the variant, the symptoms of exposure and the persistent nature of mustard remained the same. Only the purity of the agent and the weather determined the length of persistence once deployed. While both sides used the phrase “gas” to describe all chemical weapons during the war interchangeably with “chemical warfare,” that designation was due to the early agents. Mustard is not a gas, but a liquid. Many other agents were in powder form. By the end of the war, “chemical warfare” became the preferred term, reflecting the reality of the materials used. Similarly, “war gases” became “chemical agents” or “chemical weapons.”

[17] The Blue/Green Cross shells were non-persistent pulmonary agents and sternators (sneezing agents) and tear gases. The weapons did not penetrate filters in the way the German’s expected, but did force the defending forces to put on their masks, which always resulted in casualties due to improper wear, panic, or among those caught unprepared. The wearing of the British SBR in particular degraded individual and unit operational effectiveness as it was difficult to see, hard to breath, and isolating to wear the mask, let alone aim and fire a weapon. The mouth tube also made it impossible to speak. Therefore, while the blue/green cross shells were not directly effective in producing casualties from gas, they had secondary effects of tactical benefit. Incidentally, protection from the German shells was accidental, the result of an addition to the mask filter for another purpose.

[18] See Amos Fries, “Gas in Attack and Gas in Defense,” National Service Magazine, (June and July) 1919: 23, (accessed November 26, 2014). Fries is not entirely correct in his assessment. The Germans did develop better dispersal means for their chemical shell as the war dragged on, but the proper ratios and production standards were later developments, after the war. The estimations Fries frequently made, while generally acceptable at the time, were actually guesses and later challenged based on scientific research and analysis. The effective dispersal of chemical agents in artillery shell is a very tricky business. Too much HE, and the chemical is destroyed, too little and the liquid is never properly dispersed. For example, VX rounds in the US inventory developed in the Cold War had a fifty-fifty chance of either burning up the chemical entirely on detention, or properly dispersing it in vapor form. Further, the fusing of the rounds had to be just right to achieve a detonation above ground, preferably meters above ground. Too low and the chemicals were buried in the mud, too high and the wind dispersed them. Much of this was beyond the technical and material limits of the belligerents in the war, though the interwar years saw significant improvement.

[19] Prentiss, 647-685; Gilchrist.

[20] David T. Zabecki, The German 1918 Offensives: A Case Study in the Operational Level of War (London: Routledge: 2006), 113-173; For a full examination of the Spring Offensives see also Zabecki, Steel Wind: Colonel Georg Bruchmüller and the Birth of Modern Artillery (Westport, Conn: Praeger, 1994).

[21] Erich Ludendorff, My War Memories, 1914-1918 (London: Hutchinson & Co. 1919), 482.

[22] Zabecki, The German 1918 Offensives, 328.

[23] Spiers 38, 44.

[24] Ibid.