20 July 2020
Gerald Prenderghast describes the use of poison gas and gas masks employed during the Great War.
Chemical weapons are no new invention. They were used by the Chinese, Greeks and Romans as poisons or lethal gases, although it was during the Great War that they were first employed on a large scale and consequently reached a final, sickeningly effective hiatus. Gases used during WWI were of two main types: those designed only to debilitate the enemy, such as the various forms of tear gas and mustard gas in low concentrations, and a much more commonly used collection which were employed to kill, such as chlorine and phosgene.
THE POISON GASSES
Tear gasses: As the name suggests, the initial effect of gases in this class is to produce severe eye irritation, although prolonged exposure also causes respiratory and skin irritation, vomiting and eventually blindness. The use of tear gas was limited, except in the early years, and these substances are usually considered to be debilitating rather than lethal agents, although most will cause death by asphyxiation, if a victim is exposed for long enough.
Poison gases: Much more dangerous than the tear gases, these substances were released with the intention of producing a lethal effect on any troops who encountered them. The three most commonly used gases were chlorine, phosgene and mustard gas; chlorine and phosgene were found to be more effective when delivered as a mixture.
Chlorine (Chemical symbol: CL2): Chlorine is a yellowish-green gas at room temperature (15-20°C) and even short periods of exposure can cause permanent damage to the eyes, nasal tissues, throat and lungs, often resulting in a painful death, the chlorine probably combining with moisture in the lungs to form hydrochloric acid. As it is an element, rather than a complex chemical compound, it is relatively easy and cheap to manufacture, although, unfortunately for the purposes of chemical warfare, it is heavier than air.
This property meant that troops who stayed at their posts during a chlorine attack suffered less than those who ran away, as movement worsened the effects of the gas, while those who stood up on the firing step often escaped any serious effects at all. The nature of the gas singled out those below the parapet, particularly the wounded who lay on stretchers or the ground. Chlorine proved to be relatively ineffective as a weapon, particularly as soon as simple countermeasures were introduced. It dissolves readily in water, so simply covering the mouth and nose with a damp cloth was effective at reducing its effects, although a cloth soaked in urine was even more effective, because the chlorine combined with urea to form inert di-chlorourea. The gas also produced a visible greenish cloud and strong odour, which made it easy to detect at long distances, allowing gas masks to be fitted in good time. Despite these disadvantages, chlorine was a good psychological weapon, the sight of that noxious green cloud filling the opposing infantry with dread. As one British officer put it: “It was remarked as a joke that if someone yelled ‘Gas’, everyone in France would put on a mask. Gas shock was as frequent as shell shock.”
Chlorine was the most commonly employed gas in WWI; a total of 93,800 tons were used. Referred to as ‘Red Star’ by Allied troops because of the marks painted on the cylinders containing the substance, it could also be delivered by gas shell.
Phosgene (Chemical symbol: COCL2): Developed by a group of French chemists headed by Victor Grignard, this gas was an improvement over chlorine, as it was colourless and had a pleasant odour reminiscent of cut grass. Deadlier than chlorine in its eventual effects, its use as a weapon was limited because the effects of phosgene poisoning could take up to 24 hours to appear. This meant that its victims were initially still able to fight, although apparently fit troops would be incapacitated by the effects of the gas on the following day. Phosgene poisoning is almost impossible to treat successfully, because inhalation results in irreparable damage to the tissues of the lungs, causing symptoms which initially included coughing, burning eyes and throat, nausea, vomiting, difficulty breathing and, eventually, suffocation.
More than 80% of gas fatalities during WWI were caused by this chemical, although its effects were significantly less well publicised than the results of mustard gas poisoning.
Approximately 36,000 tons were used during WW1, mostly by the German Army (18,000 tons) and the French (15,000 tons). It was usually mixed in equal volumes with chlorine, which helped to spread the denser phosgene, the combination being termed ‘White Star’ by the Allied troops, because of the marking painted upon the shells containing the gases. The phosgene-chlorine mixture proved more effective when delivered by shell, however; its greater density did not lend itself to wind-borne dispersal.
Mustard gas [(ClCH2CH2)2S]: Perhaps the most psychologically effective of the chemical weapons employed during the Great War and certainly the most widely used, mustard gas is a yellow-brown liquid at room temperature and has an odour resembling mustard plants or garlic, hence its common name. Its symptoms include: extensive blistering of the skin similar to third-degree burns, conjunctivitis followed by temporary blindness and damage to the respiratory system, resulting in coughing, nausea and vomiting. Despite these effects, mustard gas was not a very effective killing agent and its importance as a weapon was rather in the long-term debilitation it caused to troops exposed to it. The gas was capable of penetrating layers of clothing to burn the skin beneath, thus rendering gas masks ineffective. One young British nurse wrote about the effects she had witnessed in patients suffering from exposure to mustard gas: ‘I wish those people who talk about going on with this war whatever it costs could see the soldiers suffering from mustard gas poisoning.
Great mustard-coloured blisters, blind eyes, all sticky and stuck together, always fighting for breath, with voices a mere whisper, saying that their throats are closing and they know they will choke.’ Another British nurse treating mustard gas cases wrote: ‘They cannot be bandaged or touched. We cover them with a tent of propped-up sheets. Gas burns must be agonizing because usually the other cases do not complain even with the worst wounds but gas cases are invariably beyond endurance and they cannot help crying out.’
Reliable records for the production of mustard gas are not available. It was referred to as ‘Yellow Cross’ by German troops, because of the shell marking and HS (Hun Stuff) and Yperite by British and French respectively. It was always delivered by an explosive gas shell because, being liquid at room temperature, wind-borne dispersal was impossible.
The response from both the Allies and the Central powers to gas attacks was initially very similar, beginning with the issue of a pad to cover the mouth which was simply soaked in water or urine and progressing by degrees to the more effective devices used later on the Western Front.
The first anti-gas protection issued on both sides was a simple cotton pad, soaked in an appropriate solution such as sodium bicarbonate, urine or water and used to cover the mouth and nose. In the British Army this device was known as ‘The Black Veil Respirator’ and since it offered no protection for the eyes it was useless against all types of gas. This failure in protection meant that it was quickly replaced with the Hypo Helmet or Smoke Hood.
Invented by a Canadian, Dr Cluny MacPherson, and introduced to troops on the Western Front in June 1915, this was a fairly primitive device, essentially a khaki-coloured flannel bag soaked in hypo solution (a mixture of glycerine and sodium thiosulphate) which the soldier placed over his head, tucking the bottom into his tunic. The action of breathing then forced air through the material and a fragile mica or celluloid window was provided for visibility. Approximately 2.5 million were produced between June and September 1915.
The Hypo helmet was succeeded in July 1915 by an improved design designated the P helmet, which gave a degree of protection against both chlorine and phosgene. This device was designed with two layers of flannel, the outer soaked in sodium phenolate and glycerine and fitted with an exhaust valve fed from a metal tube which the wearer held in his mouth. Nine million were produced between July 1915 and August 1918.
The PH helmet was a later modification of the P helmet that incorporated an outer layer soaked in the original mixture of phenylate and glycerine but now included hexamethylene tetramine, for added protection against phosgene. It remained in service from its introduction in October 1915 until the end of the war, and approximately 14 million were produced.
The PHG helmet was similar to the PH helmet in the chemicals used to impregnate it but fitted with foam rubber in the face-piece for added protection against tear gas. Introduced in January 1916, it proved unsatisfactory and only around 1.5 million were produced before it was removed from service in 1917.
The original French mask was another helmet or rather bag design, the M2, which was made of impregnated cheesecloth and also supplied to the AEF (American Expeditionary Force), along with the British small box respirator. Around 29 million were produced between April 1916 and the end of the war.
Small Box Respirator (SBR)
Unfortunately, all of these helmet pattern masks suffered from the same problem, in that once the chemicals they were soaked in were exhausted, the mask was useless until it had been re-treated. More importantly, it was impossible to tell when a mask became ineffective without wearing it during a gas attack, when such knowledge was a little too late. However, in 1916, these problems were solved by the introduction of what came to be known as the Small Box Respirator (SBR), which consisted of a dense canvas face-mask with two glass eye pieces and a filter box, containing activated charcoal. The filter box and the face-mask were connected by a robust corrugated rubber tube and the respirator was carried in its own canvas pack, usually strapped to a soldier’s chest. In the event of a gas attack, the user slipped the face-mask into position and breathed air filtered through the charcoal in the filter box, which removed the noxious gases, although the filter had to be changed periodically to ensure the efficient working of the mask.
The German GM-15 gas mask and its later variants
The Germans had previously produced a mask similar to the British SBR in 1915, designated the GM-15 and consisting of a rubberised fabric mask, with two large glass eye pieces, and a filter which was fixed directly to the front of the face-mask. This design was more robust than the British SBR and specifically avoided the problems of wear and breakage associated with the corrugated tube of the British respirator. Later designs, the GM-17 and GM-18, were similar except that the mask was made of leather.
Soldiers were not the only enlisted personnel felt to be in need of protection and gas masks were produced for horses, mules and dogs, while the German Army also introduced gas-tight coops for carrier pigeons.
Use in military operations
The first modern, systematic use of poison gas began in 1914, although the substances first introduced to the battlefields of France were not poison gases, but rather tear-inducing irritants (tear gases) and seem to have been intended to incapacitate rather than kill enemy troops, which also meant that their use was legal under the 1899 Hague Convention. The first recorded use of tear gas was by the French Army in August 1914, although only small quantities of gas were delivered using 26mm grenades, and the Germans apparently did not even detect its presence.
Chlorine was first used by the German Army in 1915 at Langemark-Poelkapelle, north of Ypres, the gas being delivered from a collection of large cylinders and moved towards the French lines by a slight easterly breeze. The troops subjected to this creeping grey-green menace broke ranks and fled, leaving a three-mile gap in the Allied lines. The Germans, however, were as wary of the gas as their opponents and before they could exploit their advantage, the gap in the lines was closed by French and Canadian units. The Allied governments quickly claimed that the attack was an obvious violation of international law but Germany argued that the Hague Treaty had only banned shells containing chemicals, rather than the use of gas projectors, and anyway, the French had violated the convention first. German chlorine attacks continued during 1915, and the British also made their first use of the gas at the Battle of Loos on 25 September 1915, although this attempt led to disaster, the gas in some cases being pushed back on the British lines by an unfavourable wind. More importantly, half the cylinders could not be opened because the wrong keys were supplied and subsequent shelling burst many of these containers, releasing the gas amongst the British troops.
Germany also delivered the first chlorine-phosgene attack at Wieltje, near Ypres, on 19 December 1915, although the P helmet had been issued to British troops by then and provided partial protection, and by January 1916 the superior PH helmet was quickly replacing it. The first mustard gas attack also had a German origin and was carried out during the Third Battle of Ypres (Passchendaele) in July 1917, although the appearance of the British SBR and German GM-15 had rendered most forms of gas relatively harmless. No mask could offer full protection against mustard gas, however, but by the end of 1915, gas was regarded as a subsidiary weapon, to be used with artillery rather than as a weapon in its own right.
During 1914 and much of 1915, gas attacks were delivered from cylinders mounted some distance from the enemy’s lines, relying upon the wind to push the noxious chemicals in the right direction. Unfortunately, all the gases used during WW 1 were denser than air, so dispersion by this method tended to be too slow to be very effective, especially in the case of chlorine, which had a colour and smell making it easy to detect at long distances, thus allowing gas masks to be fitted by the intended victims.
Clearly, this was not good enough and both sides began experimenting with gas-filled shells fired from howitzers, which could be directed accurately onto enemy troop concentrations. The average shell, however, did not contain enough gas to be effective, so during the period of the Somme Offensive a Royal Engineer officer, Captain W.H. Livens, devised a projector – later known as the ‘Livens Projector’ – which could throw a three-gallon drum of chemicals into the enemy trenches. When they came into regular use, these projectors were usually set in banks of several hundreds and could deliver a high concentration of gas which often caught the enemy by surprise, although the Germans were quick to copy the design and issue their own projectors. Although specifically designed for use with gas canisters, the Livens projector could also throw high explosive, oil and cotton-waste pellets, thermite, white phosphorus and even ‘stink’ bombs, which were used to discommode enemy troops when the situation was too dangerous for a real gas attack. The Livens Projector remained in service with the British Army until WWII.
COLLECTING GAS MASKS
Few of the original black veil respirators have survived into the 21st century but many of the other types can be found with a little patience and perseverance.
Original Hypo helmets can be found in good condition for around £100, although good reproductions are available from US sites for as little as £15.
Original SBRs complete with the carrying pack fetch around £200 ($245) in Britain or the US, while a good reproduction costs between £120 and £140. Individual components are relatively rare and correspondingly expensive, so it is best to spend a little more on a complete set, rather than trying to save money by purchasing something in need of refurbishment.
Although the German GM-15 masks and their later variants are relatively common, they are becoming popular with collectors and an example with the face-mask in good condition and a nice carrying case might fetch as much as £500-£700. The GM-17 and GM-18 variants are slightly less expensive, between £300 and £450. Accessories like the carrying case are also very collectable and good examples fetch between £50 and £100. Reproductions are cheaper, costing around £80, including a carrying bag.
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