Respirator, Anti-Gas, Mk. IV, the Mk. IV General Service Respirator, is an Interwar, Second World War and Early Post-War Respirator which has seen use in many different forms all over the world. Starting its life in 1926, and fitted with upgrades to box respirator containers, known as the Type A and Type D Containers, this mask was, at the time, viewed as a leading design by Britain and saw less development of the mask itself to allow for a focus on container development. This design served Great Britain throughout the war alongside its successor, the Mk. V. Versions of the Mk. IV and V continued service into the 1950s, both with the military and even in a modified state with Porton Down staff.
Write up by Baroque4Days, ensure you credit the author and use any provided references to other collectors, photographers or custodians of documents. The few parts written by others have been marked as such.
History & Development[]
In 1919, policy dictated that two containers should be designed and used by the British Armed Forces, one for training and one for mobilisation. The training container was a general upgrade to the late box respirator container, filled only with charcoal. The mobilisation container was based on the 1918 improved container, similar to the US MI Felt Canister (it is unclear which was designed first). By 1922, the training container became known as the Type A and the mobilisation container, the Type D.
During the early inter-war years, G. S. Respirators Mks. III and II were used with the container which would become the Type A. However, the need to move on from primitive features such as mouth-pieces, flutter-valves and box containers was clear and so, development on a new respirator facepiece began. By 1926, it was complete and named the Mk. IV Anti-Gas Respirator or Mk. IV General Service Respirator.
During the 1930s, the push for use of reclaimed black-rubber resulted in reduced, and eventually discontinued, use of the orange natural rubber faceblanks, though this rubber was still used to seal the eyepieces. It was also around this time that the later Mk. III Eyepieces were introduced, with two parts threaded together which would allow for easier lens replacement. New variants of the in/outlet assembly were developed and even a new faceblanks with a sealed mic port which could be cut into. This was designed to stop the need of standard and Special T Mic faceblanks.
This design became known as the Mk. V in 1939 and was issued with stockinette removed. Whilst the Mk. V G.S. Respirator did not replace the Mk. IV, it was the favoured design which saw service following the war.
The Variants[]
The Mk. IV G. S. Respirator featured the same thread-less eyepieces found on the Mk. III and was a very similar shape, however, the improvements to the older design were many. Firstly, the Mk. IV did away with the archaic flutter-type exhale valve and used a simple suspended disk-type valve in a metal housing known as a valve holder. This part also incorporated a tube which would connect by wire and tape to a corrugated, stockinette-coated rubber tube. The rubber used, initially was an orange/red rubber often referred to as "gum rubber". This, however, fell out of service in favour of the black rubber blend which enabled the use of reclaimed rubber to reduce costs. Companies such as Avon India continued to use the gum-type rubber into the mid-1930s but this was completely phased out by the beginning of the war.
The Respirator was initially created in two variants, the Mk. IV and Mk. IVA. The Mk. IV featured a short tube which connected to a container which would be sat in the haversack whilst mounted to the soldier's chest, a position referred to as "chest-position" or "alert-position". If the Mk. IV was created to replace the Mk. III G. S. Respirator, then the Mk. IVA was created to replace the Mk. II. The Mk. IVA variant featured a double-length tube, connected in the middle with a fabric part also featuring a small eyelet for securing the tube.
Over time, the requirement for communications equipment to be used was becoming more and more apparent and, as such, respirators needed to be able to be worn whilst crew operated said equipment. Whilst a simple modification to the temple area of the mask resulted in the facepiece known as the Special T (T for Temple), designed for tube with abnormal head-shapes, this design was also expanded upon to feature a hollow cylindrical boss on the left cheek with a plug attached which would allow the insertion of Respirator Microphones Nos. 1 and 2, the former for telephone switchboards and the latter for both telephone switchboards and wireless sets. This variant was referred to as the Mk. IV Special T Mic.
Container Development[]
The Mk. IV, as mentioned before, was fitted with Type A Containers for training purposes and Type D Containers for actual use. The Type D Container contained proper filter component which allowed it to function better when filtering nose gases, something the Type A, and other box respirator containers were unable to filter. Due to the increasing ease of developing nose-gases, particulate protection was something which scientists began to focus on. The first step was in moving from the older box container to the first true anti-gas container, the Type E of 1929.
The Type E Container was composed of two sets of two pads, diaphragms and charcoal. The pads improved the level of filtration by using a mixture of wool and asbestos fibre, claimed in 1989 by Porton Down to be roughly 80% wool, specifically Merino Sheep Wool, and 20% Asbestos, specifically Crocidolite (Blue Asbestos). After some time, this design would become known as the Type E Mk. I as improvements began to be worked on. At an unknown date in the early 1930s, a new standard service container was introduced with a variety of general improvements, supposedly including an improvement to the housing of the filter from type No. 4 to No. 4A. This filter, painted brown, as known as the Type E Mk. IV and is the second most common type to be found on surviving examples.
By September of 1939, a further improvement to the charcoal filtration had been introduced in the form of the Type E Mk. V, a buff painted casing which appears slightly lighter than the Mk. IV. It is unclear how this container different but the general purpose of the upgrades was to use materials which were readily available to Britain. By this point, the Type A "Training" Container was still in service, though no longer being produced, but the Type D had become obsolete and would be replaced with Type E model containers when necessary.
The Arsine Scare of October 1939 and the EA Container[]
In October 1939, based on research undertaken on a recovered German Respirator, it was discovered that British Type E Containers were around 10x more susceptible to the effects of Arsine Gas. This suggested to scientists that the Germans must have been planning to use this gas.
In an emergency effort to protect the British Expeditionary Forces in France, an additional container, designated Type EA, was issued so that it may be fitted to the then-current issue respirators. The container would be attached by cutting the connecting tube in half and inserting the EA container between these two halves, attaching it to the spigots at either end of the container, closing the seal again. This special container was filled with Lime Permanganate granules.
During this time, the final container for the Mk. IV and V G. S. Respirator was being developed.
By 1940, the red Type E Mk. VI Container was issued to replace older Type D and E Containers, whilst Type A Containers were still reserved for training purposes. Though this was the final time an improvement to this container was released, research continued and it was found that with further treatment to the charcoal, protection against prussic acid, cyanogen chloride and other such weapons could be implemented into the filling. Whilst never being issued with the G. S. Respirator, this type of filling was developed and eventually saw use with the successor Light Anti-Gas Respirators and their Light Mk. II Containers.
Design, Component Designations & Identification[]
Facepiece Designations[]
Mk. IV[]
The standard Mk. IV facepiece differs from the earlier Mk. III facepiece in the use of a new valve holder assembly which now uses a protected radial valve as opposed to the unprotected flutter valve. The facepiece itself was originally produced in the same natural orange rubber, or "gum rubber", that the Mk. III was made from but, at some point in the 1930s, the introduction of a reclaimed black rubber blend was introduced and was much more cost effective.
The Mk. IV is coated in stockinette, as were the original connecting tubes issued with the mask. The rubber mask was named the No. 4 rubber mask and does not differ much from the No. 5 rubber mask of the Mk. V GS Respirator besides being produced in multiple sizes and also only having a single tissot tube whereas the No. 5 mask would introduce a small block to help split the air onto both eyepieces.
Sizes Available: Small, Normal, Large
Mk. IV Special T[]
The Mk. IV Special T variant was designed for those who required spectacles. The idea behind the mask was that there would be greater pressure at the temples, hence the "T", which would allow the mask to seal around the spectacles prior to the introduction of respirator spectacles which could simple be attached to the supports inside the mask without the need for temples (the part of a pair of eyeglasses which rest on the ears) to support them.
The rubber mask used with the Mk. IV Special T respirator is simple referred to as the No. 4 Special T rubber mask.
Sizes Available: Small, Normal, Large
Mk. IV Special T Mic[]
Sizes Available: Extra Small, Small, Normal, Large, Extra Large
Rubber Mask Rubber Blends[]
Red/Orange coloured "gum rubber", or "natural rubber", was originally used to create the Mk. IV faceblank, as was the case with the Mk. III and II G. S. Respirators before it. This type of rubber, as the name implies is nothing more, nor less, than natural rubber but in a red/orange colour. Whilst natural rubber does have some desirable qualities, the desired properties of a rubber faceblank cannot be controlled when using this type of rubber and so synthetic blends were introduced to give the Chemical Defence Experimental Station, Porton better control over what the faceblank could do. This came in the form of an unknown natural/synthetic blend simply described as "black rubber". The purpose of this, initially, was to allow the use of reclaimed rubber to save costs.
Aside from the differences in rubber blend, the stockinette wrapping method changed during the 1930s, regardless of the rubber-type used. Initially, the stockinette is wrapped in such a way that the end of the wrap will be aligned horizontally along the nose area. Around the mid-1930s, the stockinette will be wrapped so that this seam will be diagonally but vertically from the eyepiece to the wire-wrap around the valve-holder assembly.
Guards, Valve, Checkplate & Seating[]
Mk. I Valve Guard:[]
Mk. I Valve Guard - GasMasksUK
The Mk. I Valve Guard was the original Valve Guard issued with the Mk. IV General Service Respirator in the late 1920s. It features 24 small holes in a circle around the lowermost part of the guard plate. The guard is secured by means of a cotter pin and retaining nut, this being the only one of the five types to use this combination of components.
The Mk. I design is assumed to have been modified to feature the later pin and securing method, a cotter pin and captive nut, and then designated Mk. I*, this designation being referenced in the 1943 Advanced Gas Training Manual. No example of this has been found and only one example of a Mk. I, in general, has been discovered as of 2020.
Mk. II Valve Guard:[]
Mk. II Valve Guard - Baroque4Days
The Mk. II Valve Guard retains the 24x small-sized holes and overall style of the Mk. I Valve Guard, but differs in its use of a captive nut, only able to be removed by means of a Valve Guard Securing Key. This captive nut is the smallest of the types which have been discovered and it can be assumed that the type potentially applied to some Mk. I Valve Guard, rehashing them Mk. I*, would have been different in size and shape.
Mk. III Valve Guard:[]
Whilst said to have existed, no photographic evidence or description has been found to shed light on what the Mk. III Valve Guard may have been like. It is unclear how much a transitionary piece it was been the very different designs, the Mk. II and Mk. IV. The design may have fit somewhere in the middle, or perhaps mimicked the earlier or laid the foundation for the latter two types.
Mk. IV Valve Guard:[]
An example of a Mark IV Valve Guard - hungryforgsr
The Mk. IV Valve Guard differs from the previous design in two ways. Firstly, rather than having 24 smaller-sized holes, the guard now has 20 larger-sized holes. The second difference is that whilst the Mk. I and II designs feature a fairly smooth transition from the outermost flat plane to the peak of the mound shape, the Mk. IV has a hard transition where there is a flat outermost circumference followed by a wall of near equal length and then a smooth mound on top.
In addition to these differences, the Mk. IV design appears to have a wire gauze beneath the valve guard, presumably attached to the captive nut and clip. This gauze may have been an earlier idea before the Mk. I checkplate was introduced to help better protect the outlet valve.
Mk. V Valve Guard:[]
Mk. V Valve Guard - Baroque4Days
Valve Guard Mk. V does not differ much from the Mk. IV and only appears to be different in the use of two slightly more pointed captive nuts and has done away with the wire gauze, previously positioned below the Valve Guard. The removal of the gauze could explain the difference in the shape of the captive nut.
Aside from this, the design still features the shape described in the Mk. IV section and also consists of 20 larger-sized holes. This Valve Guard model is by far the most common on the collectors market today.
Mk. I Checkplate[]
Checkplate, Mk. I - Baroque4Days
Introduced alongside Valve, Outlet No. 2 Mk. II, the Mk. I Checkplate was a thin disk of metal with holes in, designed to protect the outlet valve in addition to the protection afforded by the valve guard. The checkplate was also designed as a retention method, and would keep the valve in place better and more reliably than the rim of the valve guard would. Whilst no improvements to this design were introduced with the G. S. Respirator, the checkplate, as a component, was included in the first two Light Respirator valve holders, Nos. L1 and L2, as a means of securing and protecting the No. L1 outlet valve.
The checkplate did not seem to exist until the late 1930s, where it seemed to only become a requirement during the war. Older-type outlet valves were replaced with the later green No. 2 Mk. II outlet valve design and were fitted with these checkplates as a means to retain position better, as previously explained.
The checkplate is marked with the numeral "I" to indicate that it is a Mk. I and will also feature a stamp identifying the manufacturer of the component.
Mk. I Seating:[]
On the back of each assembly, the cotter pin described above is secured on the opposite end by a retaining nut which also holds a second guard in place, known as the seating. Whilst there are some differences between the seatings, due to the different sizes of valve assembly bodies, all of these types appear to be designated Mk. I. It should be noted that no documentation has yet been discovered which identifies this component as the seating, but this terminology was used in conjunction with the Light A. G. Respirator to describe the equivalent of this component.
Valves, Inlet/Outlet[]
Baroque4Days demonstrates the functionality of Inlet Valve Mk. IV.
Inlet Valves Mk. III & IV[]
Two types of inlet valve can be found inside the neck of GS-type respirator containers, one metal and one rubber. Both types can be found on containers Type E, though the rubber type seems to be the most common on the collectors market today. It should be noted that Types D and F also featured inlet valves inside the container however, it is unclear what the differences were, if any.
Different tools were required to both remove and position the inlet valves dependent on whether a Mk. III or IV was in use. More on this can be obtained under the "Inspection & Repair of the G. S. Respirator" section.
Outlet Valves[]
Early type Outlet Valve compared with the green No. 2 Mk. II Outlet Valve - Baroque4Days
Whilst the inlet valve is housed inside the neck of the container, the outlet valve is secured inside the valve assembly. It is unclear how many valve types were used since the inception of the Mk. IV G. S. Respirator, but the only type described in gas training resources, is known as the No. 2 Mk. II Valve, a complex-shaped disk valve, made from an unknown blend of rubber but always coloured green.
Though No. 2 Mk. II appears to be the only well-known type, a type with a slightly deeper depression of the rubber, and with a slightly stiffer rubber does exist. This type is marked with a later and a two-digit number and has only been found with early 1930s dates. It should be noted that the earlier types were replaced with No. 2 Mk. II valves when undergoing repair during the war, meaning it is possible to find this type most likely only on interwar dated facepieces which did not serve or undergo repairs.
It should also be noted that the early-type valve was not used in conjunction with a checkplate, relying on the earlier-type valve guards to hold it in good position. During the war, the Mk. I checkplate was always fitted to these models alongside a new No. 2 Mk. II outlet valve.
Valve Holders[]
In general, these components are referred to as the No. 4 Valve Holder. However, there were at least five different variants of the No. 4 Valve Holder, most of which have some kind of designation about them, though there is some conflict in this as some designations are given to two completely different designs.
Two styles of inlet design were used during the war, the narrow type and the wide type. The width refers to the width of the aperture in the back of the assembly body and the way in which the connecting tube mount is designed in relation to the inlet hole. Some are wide, causing a more horizontal spread airflow, whilst others are narrow, offering a much more direct flow of air.
No. 4, Mk. II:[]
Presumably the earliest official model, the No. 4 Mk. II can be traced back to the late 1920s and served with both Mks. IV and V G. S. Respirators throughout their service life and can be configured with all five types of valve guard. Today, this model is by far the most common type.No. 4 Mk. II features a small, light and single piece metal construction which is notably thinner than other types. This design, though clearly a lot more dated, appears to have been the highest quality out of the four available designs. Though it is unclear how the component was made, it does appear that the entire construction is of one piece of metal as there are no visible weld lines.
This design features a narrow inlet tube leading to a circular aperture on the back. Despite the aperture being narrow, the shape of the body allows the construction to smoothly transition from the narrow tube connector mount to a wide opening on the back. protect the valve, six spokes can be found underneath the checkplate on the back.
No. 4, Mk. ?:[]
This design may be the No. 4 original, or No. 4 Mk. I. The only known example seems to include only the No. 4 part of the designation but no Mark to complete the designation. It shares a lot in common with the No. 4 Mk. II design from the width of the inlet, the two flat faced areas to the side of the connecting tube mount and a fairly rounded inlet. Unlike the No. 4 Mk. II, this design features visible welding on the back.This design features a separately made connecting tube mount which, whilst clearly well attached to the front, smelting the two pieces of metal together smoothly, the rear features a fairly crude welding job. Unlike the Mk. II which, on the rear, allows the narrow inlet to spread out evenly with a ramp like design making a very smooth transition between inlet and the back of the body, this design merely features a narrow hole positioned into a recess with no attempt to span the air out further.
This design is the least common on the collectors market today and can be found on both Mk. IV and V G. S. Respirators from time to time.
No. 4, Mk. III (first type):[]
The No. 4 Mk. III design is often found on Special-T, Mic variants of the Mk. IV G. S. Respirator, but can be found on standard Mk. IV and V respirators as well. No. 4 Mk. III is an inferior design in terms of quality with a much heavier total weight and higher amount of visible welding. The tube connector mount and main body are both separate components. The way in which the two are connected works by the mount being fed through a slightly widened inlet aperture and then locked in place by folding back the metal on the mount from the back of the assembly. These parts are then welded on the rear, leaving a small crack of liquid to build up due to the lack of weld on the front, a major flaw in the design.
This type does not feature the smooth transitional aspect of the No. 4 Mk. II and merely has a walled-in recess on the back where the welded on inlet area is located. Whilst wider than the Mk. II design, the increased width has also made the inlet more narrow vertically, likely removing any benefit of the design.
No. 4, Mk. III (second type):[]
The designation of this assembly is somewhat confusing. This is the second "wide-type" assembly but is very different from the other. Regardless, it does appear that both are marked No. 4 Mk. III. As of now, there is no official documentation to explain the differences properly, so it must be understood that there are two types with the same designation. This design specifically is the second most common and is more typically on Mk. V G. S. Respirators, though it can be found on both of the wartime respirators.This design, from the front, appears to be a single piece of metal but does actually feature two parts welded together. In spite of this, the quality of the construction should be credited. It appears to take the base of the No. 4 Mk. II design, widen the inlet aperture size and then weld a wider sloped plate over the modification. The two sections of flat exposed face from the No. 4 Mk. II design appear to have been removed for this aperture extension. This can be seen where the lower part of the tube mount is visible welded to the smoothed angle piece.
Eyepieces[]
"Snap-on" Eyepieces:[]
On earlier production models of Mark IV G.S. Respirators (anywhere from 1926 ≈ 1936), it is common to find "snap-on" style eyepieces fitted on the faceblank. These eyepieces were presumably of a two-piece design, with connection occurring by locking the pieces into one another through pressure. These eyepieces were likely the same kind seen fitted on the Mark II and III G.S. Respirators, and may have also been referred to as "Mark II Eyepieces", but this information is currently unknown.
Mk. III Eyepieces:[]
The Mark III Eyepieces are the most common type of eyepiece seen on Mark IV G.S. Respirators, with them being seen on examples from approximately 1938 all the way up until the end of the war. The Mark III Eyepieces can be found in two variations, which will be referred to as "Mark III Eyepieces A" and "Mark III Eyepieces B" due to lack of clarification between the two designation-wise and for distinguishment.
"Mark III Eyepieces A" are comprised of the lenses, gum rubber seal/ring, and threaded outer caps. The eyepieces made this way to allow for easy removal of damaged lenses and replacement while in the field. To remove the lenses, expose the outer ring and rotate counter-clockwise, which will expose the lens in its entirety, where it can be popped out (which will break the gum rubber seal around the lens).
"Mark III Eyepieces B" were likely made to succeed the original "Mark III Eyepieces A" due to them being seen much more often on late war produced Mark IV & V G.S. Respirators, with the primary difference being in the removal of the outer threaded cap and addition of a more secure threaded eyepiece. Removal of these eyepieces would be achieved through a specialized tool that would be inserted into the slots, and then would be turned counter-clockwise which would allow for removal. This type of eyepiece would later be reused (and redesignated) with the Light Anti Gas Respirator.
Head-Harnesses[]
Example of No. 4 Mks. I, II, III & IV (multiple collectors)
The four types of headharnesses used during the life of the Mk. IV respirator were designated in the format "Buckles, Loop", as in No. 4 Buckles, Mk. III Loop. Whilst four types are said to have existed, only two of these types have been found on British respirators, with scarce examples of the final version on a few post-war Canadian Light-Type Respirators.
No. 4 Mk. I[]
Headharness No.4 Mk. I utilizes a thin canvas material head-pad, connecting a 6-point elastic webbing system to the respirators faceblank. This style of headharness was likely used from the start of the Mark IV GSRs production until 1930 ≈ 1931, where the updated No.4 Mk. II headharness replaced it.
No. 4 Mk. II:[]
Headharness No. 4 Mk. II, like the No.4 Mk. I, features a canvas head-pad connecting a 6-point elastic webbing to the faceblank of the respirator. Although similar in appearance to the No.4 Mk. I, the No.4 Mk. II head-pad was made much more thicker than its predecessor. This type is commonly thought to have been a unique design for the Light-Type Respirator when in fact it was originally a G. S. Respirator harness.
No. 4 Mk. III:[]
Headharness No. 4 Mk. III is the most common harness on the collectors market today and features a rubberised headpad of a more complex shape than that of the No. 4 Mk. II headharness. No. 4 Mk. III features individual elastic webbing (straps) fed through a system on the headpad, all reaching 6 points on the respirator faceblank.
No. 4 Mk. IV:[]
Like the No. 4 Mk. II headharness, No. 4 Mk. IV features a canvas headpad and is somewhat less complex than that of its direct predecessor, No. 4 Mk. III. No. 4 Mk. IV improves on the Mk. II design by featuring two tiers of canvas pad, the outer with 4 buckles attached and the inner with only 2. The example shown here is how the design appeared in the 1950s under Canadian manufacture for use with Canadian Light A. G. Respirators, this one a Mk. I Type from the collection of A. Hubert.
Tubes, Connecting[]
Short-Type:[]
[]
Alt Short-Type:[]
Containers, Anti-Gas[]
Type A:[]
Based on the Box Respirator Container of the First World War, the Type A Container served as a training container due to its inability to filter nose-gases. This flaw is caused by the lack of particulate filtering, something that WW1 containers are generally known for. This container was properly introduced in 1922 and served as a training container until 1939, where it can be assumed that Type E variants were produced in such numbers that they were used for training to better fit the haversacks.
Type A Mk. I
[Undergoing research]
Type A Mk. II
[Undergoing research]
Type A Mk. III
[Undergoing research]
Type A War Gases:
Much like the Type E War Gases canister seen a bit further down the page, you may rarely be able to find G.S. Respirators fitted with a Type A War Gases canister. These canisters are typically painted with a blue/grey colour, but have also been found with alternate colours (see below). Unfortunately, there is no known documentation on these types of filters and what exactly they were made for. However, due to them typically being found paired with non-military facepieces (i.e. Vit-Air) it may have been intended for private/industrial use.
Type C:[]
The Type C container has not yet been properly researched, however, based on references to the container, it can be assumed that the container was primarily produced around the early 1930s, with the primary feature of the respirator being a 24-pad filtration system. It is unclear whether or not the Type C had any gas filtration ability based on the theorised number of pads inside the canister body.
Type D:[]
Based on the Improved Box Respirator Container of 1918, a design very similar to the US MI Felt Filter (it is unclear which came first), the Type D Container was introduced alongside the training-spec Type A to serve as the "mobilisation" container, or, in other words, the service container. The Type D featured a primitive particulate filter which, whilst superior to that of the box respirator containers, was still not fit for the oncoming threats of the Second World War.
The Type D container consisted of a cellulose pad, named "Pad D" which acted more as a bag containing the charcoal granules. Once air passed into the inlet valves via the top of the container, under the roof, the air would pass through this cellulose layer and into the charcoal. Next, the air would pass through turkey towelling surrounding a gauze tube. The air, at this point, would then pass out of the container and into the connecting tube.
Type E:[]
Greenlizard56's section opening...
Type E filters consisted of a filtering matrix of fibre pads and activated charcoal. The fibrous pad section of the filters was comprised of Merino-Wool noils and asbestos fibres. The rationale behind the two-fibrous constituents was based on the fact that asbestos, whilst possessing inherently satisfactory filtering abilities, tended to mat (and consequently decreasing filtering efficiency and increasing breathing resistance), so the wool noils served to keep the asbestos fibres separate. Whilst the generally accepted ratio of 80% noil to 20% asbestos gave satisfactory filtering ability, Green (1936), notes that particularly fine asbestos ('fine' meaning its fibres are more fully opened) could potentially constitute only 5% of the filtering medium. Green also states that if the asbestos is poorer quality its ratio inside the filter should be increased, but must not exceed 30%. Crocidolite (blue asbestos) was preferred for military filter application as its fibres are much smaller, leading to less breathing resistance.
Green also notes that in place of wool noils other fibrous textiles may be used during filter construction. This included Cotton, Cellulose, Silk (real or artificial), hair, spun glass or slag wool (mineral wool), however, it is unlikely any of these substitute textiles were ever actually used.
Greenlizard56's section close.
Type E Mk. I:
The Type E Container was created in an effort to improve the quality of particulate filtering. The E Mk. I, specifically, is of an unknown colour and can only be assumed to bear resemblance to the other Type E Containers though, if the of source 1 reading is correct, it may not have featured the ribbing on the upper part of the container body. If this were the case, the designation of the body would be No. 4 as opposed to No. 4A, the designation seen stamped on to the base of most Type E Containers. Unlike the Type D, with a central, cylindrical particulate filter, the Type E opted to feature two inlet slots on the side of the casing, at the bottom, with two sets of 80% Merino-Wool/20% Crocidolite (Blue Asbestos) pads, each pair suspended inside a metal casing. As more models were developed, this container would become the Type E Mk. I Container by name.
[Undergoing research]
Type E Mk. II:
[Undergoing research]
Type E Mk. III:
[Undergoing research]
Type E Mk. IV:
The E Mk. IV Container of the Type E series can be identified by its use of a brown paint. As with other containers in this series, the identification "E IV" will be bossed into the bottom plate of the container. The Type E Mk. IV improved the metal casing by, supposedly, adding the ribbed effect on the upper section. This new casing became known as the No. 4A, as mentioned before.
Just as before, the Type E Mk. IV features the same two inlet slots leading to two pairs of filter pads, diaphragms and charcoal. This container was notably inadequate in regards to arsine gas filtration and can often be found with the small EA Container attached.
Type E Mk. V:
The E Mk. V Container has been confused in the past with a slightly taller container painted in a grey-blue. The actual Type E Mk. V Container is very similar to the Mk. IV and seemed to only have been created to use more materials which Britain had ready access to and reduce the use of what we were short on supply of. It is unclear whether or not there were any improvements to the filtration but, considering the fact that both the Mk. IV and V served alongside each other in the early days of the war, it is unlikely.
The actual Type E Mk. V can be identified by the "E V" marking on the base of the container and also by its "buff", almost beige colouring. This colour can easily be mistaken for the brown E Mk. IV but when placed together, the difference is very clear. This container was notably inadequate in regards to arsine gas filtration and can often be found with the small EA Container attached.
Type E Mk. VI: The E Mk. VI, the most common type of filter on the market today, can be identified by its use of a bright red paint, the metal lips around the two inlet holes and the "E VI" marking on the base of this container. The E Mk. VI was developed to replace all other containers except for the Type A as these were only used for training. The Type E Mk. VI was specifically developed to end the need for the EA Container as a means of filtering arsine gas, a gas which, in the end, proved too difficult to generate for the Germans.
Type E War Gases & Arsenical Smokes:
A mysterious container can sometimes be found fitted to the Mk. IV G. S. Respirator which does not bear a designation marking. This container could be considered similar to the Type E Mk. VI in that it was specifically designed with the threat of arsine gas, and thus, arsenical smokes, in mind. The container is painted in a blue/grey colour, similar to that of the Type A container, and is housed in the No. 4A canister (the style as the Type E Canister), but has been also found housed in Type A style canisters. It is unclear whether this was a minor upgrade of the Type E Mk. VI, a pre-Mk. VI prototype or limited issue model, or perhaps an industrial container with no manufacturer markings.
It is important to note that in the past, this container has been confused with the buff-painted Type E Mk. V. Of course, this container is very different from the E Mk. V in that it actually has been designed to work against arsine, something that Types E Mk. IV and V were unable to handle without the fitting of the Type EA Container.
Type EA:
As detailed in under the "Arsine Scare" section, under History & Development, the existing Type E Mk. IV and V containers were unable to filter the smokes that would come alongside the generation of arsine gas, and seemingly also would not have held up well against the poisonous qualities of the gas either. Whilst they were likely to unable to use the improved filter material to block out the smoke, they were able to deal with the poisonous element with the chemical lime permanganate.
This chemical came in a granual form and was stored in the EA extension container. The container would have to be attached by means of wire and tape to the spigots on either end of it. The original hose would be cut in half to allow the connection, leaving the container exposed between the facepice and haversack. Of course, the mass issue of te Type E Mk. VI container allowed for this crude, ad hoc, emergency design to be completely removed from service.
The canister, or the body of the container, was actually designated the No. 5 canister, the canister used with the others in the Type E series being either Canister No. 4 or 4A. This somewhat conflicts with the fact that the Type F container was invented between the advent on the Type EA, meaning a 5th canister design already existed, which should make the EA canister the No. 6. This could imply that the No. 5 canister was produced earlier or that the canister for the Type F was not considered non-experimental by 1939.
The Inlet Slot Variations:
There were a few types of Type E Mk. VI Container, the three most common types were marked V4, V5 and V7. This designation can be found on the base of the container just above the "E VI" designation. The difference in these three types was seemingly limited to the support method applied to the two inlet slots.
V4 did not feature any additional support to the inlet slots, much like previous containers, however, V5 and V7 did actually include additional support for the inlet slots.
V5 variants feature a vertical metal panel attached in the centre of the lower of the two inlet slots.
The V7 variant has a loose fitted rectangular metal pin which is bent out at the front to keep it in place. The V7 also features an oval lip around the inlet slot, possibly the take some impact force off of the slot.
Other variants exist with markings such as U5 (found on an E Mk. VI) and W25 (found on an E Mk. IV). The container marker U5 seems to be essentially the same as the V4 seen above but actually has slightly larger recesses around the inlet slots and it seems that the recessed pieces are actually separate sheets of metal. There does not seem to be any link to manufacturer and multiple examples baring the designation V4, 5 or 7 can be found to have the same traits as discussed above, rendering the non-V-type Type E Mk. VI Containers something of a mystery.
Type F, formerly Type X:[]
An Experimental design was created in the early 1930s known as the Type X was designed to provider lower breathing resistance than the fairly new Type E. By the late 1930s, this container was known as Type F Mk. I. This container featured a cylindrical body with a band of small holes positioned around the circumference of the drum at the top and bottom. It's filter composition was based on the use of esparto grass pulp which would be made from boiled esparto grass. Due to the difficulty of acquiring such grass in the 1940s, production of these filters was fairly difficult, and there were many conversations between the C.D.E.S, the Ministry of Supply and companies responsible for the supply of the grass.
One major issue with this container was that the damp grass would grow mould and so, Porton devised a way to treat grass to prevent this which would be used in the Type G container.
Type G:[]
Though no photographs have yet been found of the Type G container, it is understood that Type G containers were fairly similar to the Type F Mk. I, in that they were based on the use of grass pulp. The key difference between between the two was that the Type G container was often treated with different chemicals to help prevent mould growth, an issue present in Type F containers. These containers were issued to the Admiralty of the Royal Navy for unknown reasons but the demand for them was unable to be met. The Admiralty requested about 3,000 per week in terms of production speed but the CDES were only confident that 2,000 per week could be produced. The Admiralty wished for there to be one spare Type G container for every issued Mk. IV or V respirator fitted with that contain in case chemical warfare began. Fortunately for them, it never did.
Type G Mk. I
[Undergoing research]
Type G Mk. II
[Undergoing research]
Haversacks[]
Mk. I:[]
The Mk. I haversack was initially introduced in the first world war for the Box Respirator. This design featured a sling attached by means of two metal rings, a simple button-down flap which covered two pockets, some slightly wider than the other, which would house the facepiece and container. This design proved effective enough to house the G. S. Respirator until the increasing requirement to carry additional anti-gas equipment became apparent, which called for the inclusion of more storage.
Mk. IV & IVa:[]
[Undergoing research, contact Baroque4Days for further information]
Mk. V:[]
The Mk. V haversack was the first actual General Service designed haversack, the Mk. I being designed in the first world war for the Box Respirator. The Mk. V improved the older design in a few very significant ways. Firstly, the leather shortening tabs were removed from the design and instead, the sling was extended and sliding buckles were added to allow the wearer to adjust the length of the sling so that the carrier could be carried in the alert position, or in other positions to the side of the man.
The second difference was that this design featured a third, central pocket, directly in front of the container and facepiece pockets of the Mk. I design. This pocket was implemented to allow for the storage of personal anti-gas equipment, and also for the extended tube excess of the Mk. IVA design with the long-type connecting tube. A slight alteration to the Mk. V was available to those using the long tube respirator known as the Mk. VA. This design differed only in that it featured an additional sling to secure the haversack at the waist, removing the need to rely on the more flimsey whipcord.
Mk. VI:[]
The Mk. VI haversack greatly improved on the Mk. V design by adding two additional pockets to the rear of the haversack. These two pockets can be used to store the anti-gas eyeshields carton and two tins or dishes of anti-gas ointment. This helped to enable faster access to these items when the respirator was stored in the alert position, as these pockets would be facing out front. In addition to this, the change also helped move A. G. equipment out of the large pouch inside the main section of the haversack to reduce clutter.
As with the Mk. V, a Mk. VIA variant was also offered to those using the long tube respirators which included the exact same modification, an additional sling to secure the haversack at the waist.
Mk. VII:[]
The Mk. VII was a simplification of the Mk. VI design created to both improve on some features and, of course, cut costs. The primary goal was to remove as much metal from the design as possible. The most notable case of metal reduction is in the sling. The sling was previously attached to two rings, attached to the haversack body. The Mk. VII had the sling sewn to the haversack permanently to do away with this unnecessary feature. Many other metal parts were either replaced or removed if deemed unnecessary.
The Mk. VII did also improve on the Mk. VI design by implementing a small pocket to store the whipcord and also a button designed to wrap the whipcord around to speed up the donning procedure where the whipcord would need to be unfastened and fastened.
G. S. Respirator Drill[]
Respirator Drill can be found explained in great detail inside the Gas Training Pamphlet of 1942 and, of course, is still present in copies with the 1943 Light Anti-Gas Respirator addendum. Gas Training is broken down into 4 sub-sections, the act of donning (putting on) the respirator, removing it, cleaning/caring for it and storing it.
Donning/Doffing the Mk. IV G. S. Respirator[]
Respirator drill for the Mk. IV and V G. S. Respirator has been covered in the 1942 Gas Training Pamphlet. Whilst the basic instruction was used universally during the war, even with the Light A. G. Respirator, the G. S. Respirator instructions do offer differences in donning drill depending on which carry position is utilised.
From alert positions:[]
- Stop breathing.
- Place steel helmet to back of head.
- Withdraw facepiece quickly from haversack.
- Remove eyeshield and place in haversack.
- Hold facepiece with thumbs under the two middle and lower elastics.
- Dig chin in and bring headharness over head so that centre elastics are approximately horizontal.
- Remove any folds in facepiece or twists in headharness.
- Breathe out hard, to clear gas from inside facepiece.
- Replace steel helmet and adust chinstrap.
- Steady long tube by attaching S hook (which is on becket of tube) to any convenient part of equipment or buttonhole of clothing.
From slung position:[]
- Stop breathing.
- Unbuckle belt and bring haversack to front of body.
- Unfasten press buttons with sharp pull.
- Obtain protection as already taught. (under "from alert positions" above).
- With short tube, pull left portion of sling downwards and so raise haversack on to chest. Shorten left portion of sling. Rebuckle belt, and secure haversack by passing whipcord round body, using small Ds. or whipcord button.
- With long tube, return haversack to side and rebuckle belt (connecting tube outside).
From wading position:[]
- Stop breathing.
- Unbuckle belt and release sling.
- Bring haversack to front of body.
- Unfasten buttons with sharp pull.
- Obtain protection as already taught. (under "from alert positions" above).
- Rebuckle belt.
- With short tube and Mark VI haversack, fasten the S hook and eyeletted tab together, and secure haversack bassing whipcord round body, using small Ds.
- With long tube, adjust haversack in alert position.
From carry position:[]
- Stop breathing.
- Release whipcord.
- Bring haversack over right shoulder to front of body.
- Unfasten press buttons with sharp pull.
- Obtain protection as already taught. (under "from alert positions" above).
- Secure haversack by passing whipcord round body, using small Ds. or whipcord button.
Should the respirator need to be adjusted at any point whilst wearing, troops were given the following instruction:[]
- Hold the facepiece with the thumbs under the two middle and lower elastics.
- Dig the chin in and bring the headharness over the head so that the centre elastics are approximately horizontal
This was essentially a repeat of earlier steps of the donning procedure.
Removing the Mk. IV G. S. Respirator[]
As was the case with donning the G. S. Respirator, the removal procedure was also universally practiced whether the mask was a General Service-Type or a Light-Type.
- Insert two fingers of either hand between the facepiece and chin.
- Remove the facepiece with an upward and outward movement.
Storing the Mk. IV G. S. Respirator & issued A. G. Equipment[]
Correct storage of the Mk. IV G. S. Respirator by Baroque4Days
Once the Respirator had been removed and decontaminated, to store it back in the haversack, the following instructions were given:
- Place the container, with the inlet slots towards the centre, in the large right hand pocket of the haversack.
- Hold the facepiece in the right hand, allowing the headharness to fall inside, fold by pressing the eyepieces together and place in the large left hand pocket of the haversack the headharness towards the centre.
Should the respirator be fitted with a long-type tube, it is believed that the excess tubing should be tucked into the centre-frontal pouch, as many examples still packed in haversacks, which were previously issued during the Second World War, can be found in such a state.
In addition to storing the respirator according to this method, anti-gas equipment should also be stored in the appropriate sections of the respirator haversack. When a Mk. I or V haversack is in use, with no pockets on the rear, it is believed that all A. G. equipment would be stored loose in the centre-frontal pouch of the haversack, in front of the stored container and facepiece. If a Mk. VI or VII haversack is in use, additional pockets are included on the back for carriage of extra equipment.
Ensure that the smaller pocket on the left of the haversack is filled with 2x tins of anti-gas ointment, and the larger righthand pocket is filled with 1x carton of 6x anti-gas eyeshields. All wartime haversacks feature a secured tape-loop for storage of the tubular-tin style Mk. III, IV or V anti-dimming outfits. Additional kit, such as brassards and cotton waste should be stored in the front-centre pouch.
Methods of Respirator Haversack Carriage[]
Four methods of carriage are described in the gas training manual, each with a specific set of instructions on how to don the respirator whilst using each of the four positions. Each method had its own unique advantages and disadvantages, typically weighing between ease of carriage/lack of general interference and how fast the respirator could be donned from the position in question.
Alert Position:[]
Men wearing respirator haversacks in the short tube alert position, Australian War Memorial
The alert position has become the most iconic position of carriage for the G. S. Respirator and has been in service in Britain since the first world war. The goal of this position was to allow for the fasted method of deploying the respirator. Of course, this position was only available to standard short-tube users.
Short Tube (Mk. IV G. S. Respirator):
- Haversack well up on chest, flap next to body with press buttons unfastened, sling down back.
- With Mark VI haversack, whipcord passed through sling at back and fastened tightly with slip knot to small D on left hand side.
- With Mark VII haversack, whipcord passed through sling at back and fastened tightly to whipcord button on right hand side, making one and a half turns round button and securing with sharp pull.
Long Tube (Mk. IVA G. S. Respirator):
- Sling over right shoulder and haversack at left side.
- Haversack flap next to body with press buttons unfastened.
- Whipcord fastened round body using small Ds, or whipcord button, to hold haversack stead.
Note: The component described as the "whipcord button" is the round, lipped disk attached to Mk. VII haversacks on one side to the bottom of the haversack and was included as a faster means of securing the whipcord string as compared to the method used with Mk. VI haversacks.Slung Position:
Slung Position:[]
The slung position was established to help keep the respirator out of the way but also retain a level of alertness. This position could be employed with both short and long tube types.
- Sling over right shoulder, above shoulder strap of blouse.
- Haversack at rear, just below belt.
- Flap next to body with press buttons fastened.
Wading Position:[]
The wading position was employed when the man needed to traverse water. The idea behind this position was to keep the haversack above water level at all times.
- Haversack at back of neck, flap next to body with press buttons fastened.
- Sling brought over head and unbuckled belt passed through it.
- Belt rebuckled and sling shortened so that respirator is held steady.
Carry Position:[]
The carry position is the least cumbersome of the four carry methods but is also the most "risky", in that it would leave the man fairly unprepared should an unexpected chemical attack occur. However, procedure on how to don the respirator as quickly as possible from this position was included.
- Sling reduced to shortest extent.
- With Mark VI haversack, whipcord passed through right hand small D.
- With Mark VII haversack, whipcord given one turn under the whipcord button.
- Sling over right shoulder, haversack on back, flap next to body with press buttons fastened.
- Whipcord brought round right side of body and secured to whipcord loop with quick release bow.
Cleaning/Disinfecting the Mk. IV G. S. Respirator & Haversack[]
Caring for the Mk. IV G. S. Respirator[]
Inspection & Repair of the G. S. Respirator[]
Outlined in the 1943 Advanced Gas Training Manual were various guides to the repair of some of the G. S. Respirator components, alongside those of the Light A. G. Respirator.
Faulty Headharness[]
Headharnesses No. 4 Mks. I, II, III and IV are mentioned in this section, but it is immediately said that only No. 4 Mk. III can be field repaired, and No. 4 Mks. I, II and IV must be replaced entirely. This can be done simply by prising the tags open, removing them, and lastly feeding the elastics out of the buckles. The loops and tags were regarded as serviceable, and so if undamaged, they should be kept for spares.
The repair of a No. 4 Mk. III harness could either involve the entire replacement of the component, or the simple replacement of individual elastics.
- Should a new harness be fitted, the elastics were to be threaded through the headpad loop and then fed through the appropriate buckle on the respirator facepiece.
- The end of the elastic would then be brought back to the loop.
- A tag was then fed through the loop with the open edge facing outwards and held secure.
- The end of the elastic was to be inserted into the open edge of the tag after doubling over the elastic to the extent of 25 mm (1/4 inch).
- The tag was then to be closed with pliers or by means of gentle taps from a hammer. The split ends of the elastic should be hidden away inside the tag.
Note: The webbing of choice here would have always been what was loosely described as "Type 1" when compared to two "Light-Type" elastic webbing materials. This type can be identified by its black colour with a single, solid line running down the centre.
Damaged Eyepiece Discs[]
Providing the respirator was fitted with Mk. III eyepieces, whether slotted or not, the glass eyepiece discs could be replaced with the right tool. It is to be assumed that the older, non-threaded type required a full replacement.
- The inner rim of the eyepieces could be unscrewed using the special key known as Key, Securing, Eyepiece, or they Eyepiece Securing Key.
- Once the front part is removed, the eyepiece discs can be removed and the rubber washer can be accessed.
- Any necessary repairs can be carried out at this stage.
- Once the discs are reseated, the inner rim should be screwed in with hand strength until resistance is felt.
- The Eyepiece Securing Key was then used to tighten the eyepieces by 1/8th of a turn.
Faulty Outlet Valve[]
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Faulty Inlet Valve[]
As mentioned in the "Containers, Anti-Gas" section, two types of inlet valve were used and located inside the neck of the Type E Container, one being a metal valve, the other being a rubber valve. These two were designated Inlet Valves Mk. III (metal) and Mk. IV (rubber).
- Firstly, the faulty valve can only be removed once the container is detached from the connecting tube, so this must occur first.
- Once exposed, Tool, Extracting, Inlet Valve No. 3 Mk. I can be used to remove the metal Mk. III inlet valve, or Tool, Extracting, Inlet Valve No. 4 Mk. I can be used to remove the rubber Mk. IV inlet valve.
- Once removed, a new inlet valve can be inserted into the container neck. This type must be the rubber Mk. IV inlet valve and not the Mk. III. Though there is no given reason why, it is clear that Britain wished to remove metal where possible, and so a rubber valve was likely just as effective and also cheaper. Prior to inserting the new valve, it should be lightly lubricated in water.
- The new Mk. IV inlet valve can be seated using Tool, Positioning Inlet Valve No. 4 Mk. I.
Rewiring the Connecting Tube[]
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Repairs to Haversack[]
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Clones of the Mk. IV G. S. Respirator[]
Antipoys[]
Siebe-Gorman used the Mk IV as the facepiece for their 'Antipoys' kit. Instead of a filter, the Antipoys mask had a metal adapter for use with the rest of the kit.
Vz.35 and other variants[]
Main article: Leyland license in Czechoslovakia
The Czechoslovak Vz.35 and the numerous civilian variants, the major difference is that they use a 42mm thread instead of a fixed tube and filter. The exhale valve covers are also slightly easier to remove as it has small grooves to improve grip.
Le Gallus[]
Main article: Le Gallus
The French Le Gallus has some major differences, which are the lack of stockinette, its tan colour, the rubber straps instead of cloth ones and the 42mm thread.
M-52[]
The Yugoslav M-2 and M-3 are copies of the Vz.35 but worth mentioning here. The main difference being the 42mm thread, the exhale valve and its cover, and for the M-3 the lack of stockinette.
Vit-Air[]
Main article: Vit-Air
Licensed clone of the Mk IV, made by J.E. Baxter. Generally sold to private civilians and ARP wardens who wanted more protection than what official government issue masks could afford.
Foreign Usage[]
Australia[]
The Mk.IV General Service Respirator would be produced and used by the Commonwealth of Australia. The masks would be produced at the Munitions Supplies Laboratories, Maribyrnong in Melbourne, Australia, and would be used by all branches of the Australian military, along with civilian institutions such as Air Raid Precautions. The mask would also be used in conjunction with the previous Mk.III General Service Respirator, along with the later Mk.V General Service Respirator and the Australian Light Anti-Gas Respirator.
Canada[]
The Canadian Mk. IV General Service Respirator
Netherlands[]
The Dutch army in exile used this mask as Model I or AG 4 (Dutch: "Algemeen Gebruik nr. 4" - General Service No.4).
Portugal[]
Portugal imported masks for the military, Civil Defence and firefighters.
Trivia[]
Media[]
In Star Wars Episode IV: A New Hope, in the Cantina, the Morseerian wore a Mk. IV Special T Mic.
References[]
- Special Weapons and Type of Warfare, Volume 1 - Gas Warfare, by Lietenant-Colonel D. J. C. Wiseman - 1951
- British Military Respirators and Anti-Gas Equipment of the Two World Wars, by Thomas Mayer-Maguire & Brian Baker - 2015
- Particulate Filters - Monograph No. 9 108, by H. L. Green & D. J. Thomas - 1951 (used by GreenLizard56)
- Photographs from the collection of Baroque4Days, GasMasksUK and from Source No. 2.
- Gas Training, 1942
- Advanced Gas Training, 1943