Associated Respirators: Respirator, Anti-Gas, Light (WWII), Respirator, Anti-Gas, Light (Post-War) & M/45 (Danish LAG)
Example of a Light Respirator - B4D
The Light Anti-Gas Containers, or just Light Containers, were four filters assigned to the various Light Anti-Gas Respirators of Great Britain. From the initial experimental design, through the early issue Mk. I to the fairly well-known Mk. II design and the compact-style Mk. III, this container has established itself as the original modern-style filter.
Light Containers only really differed in their exterior, the canister itself, and sometimes there were minor differences in filling as well as some upgrades along the way. It should be noted that only the experimental design, of which only 1,000 were ever produced, contained asbestos. All other Light Containers were filled with resin-impregnated wool.
Light Container Contents from bottom to top:
- Either the No. I.A. Canister (L Mk. I) or the Mk. II's back plate (L Mk. II)
- Diaphragm
- Either Pad, Fabric (L Mk. I) or Pads, Fabric & Cotton (L Mk. II)
- Filter (resin-impregnated wool for Mks. I to III or asbestos-wool for the Experimental design)
- Either Pad, Fabric (L Mk. I) or Pads, Fabric & Cotton (L Mk. II)
- Diaphragm
- Pads, Fabric & Cotton
- Charcoal
- Pads, Fabric & Cotton
- Diaphragm
- Either No. I. Canister (L Mk. I) or the Mk. II's No. II. Canister (L Mk. II)
Experimental Light Container[]
During the development of the Experimental Special Light Respirator for Assault Troops, a new container was created and dubbed the Mk. I Light Container, or at least the experimental version of what would become the actual Mk. I Light Container. The initial model was painted black and, due to the heavy limitations put on the team developing this, and based on the shortage of resin-wool filter material, the container used an asbestos-wool filter to save costs during the trials.
This container was made up of two sub-containers, one housing the charcoal mix and with the 60mm thread at the top of its body, and the other housing the asbestos-wool filter mix with an inlet at the bottom. This sub-container also had a distinctive lip around the base. These two were then attached together using a white fabric-tape, just as the contex pre-filters were often attached to civilian respirators during this period.
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Container, A. G., Light, Mk. I[]
The Mk. I Light Container was developed through 1941 and then issued at the very end of 1941 with the Mk. I and until late 1942 with the Mk. II Light Respirator. This container was an an ad hoc solution to the need for a new container for the newly designed respirator. The intention was for the container to be issued where needed whilst work on the Mk. II container would be undertaken. This is what happened, and it was eventually put to those responsible for the repair of respirators that all Mk. I containers hsould be disposed of and replaced with Mk. IIs.
The container is made up of two parts, also designated as containers. Containers No. 1 and 1A were filled and then taped together to form the Mk. I Light Container. Container No. 1 was the larger of the two sub-containers. It consisted of the No. 1 canister, fabric pads, cotton pads, diaphragms and the charcoal mix. Container No. 1A consisted of the No. 1A canister, fabric pads, diaphragms and the resin-wool filter mixture.
The difference between the back plate seen on the Mk. II container and the base of the No. 1A canister was the lip. As Mk. II containers feature a recessed back plate, pressed into the drum of canister No. 2, there is a visible lip around the bottom rim of the container. This does not appear on the Mk. I as the lower-third of the container is, of course, a seprate container itself (No. 1A). Aside from this, the tape, or marks where tape used to be, can also be used to identify this container.
One of the key differences actually is in the markings. As explained in the diagram, and shown in the photo, the Mk. I container features markings on both of the sub-containers to indicate which is which, along with dates of manufacture. In addition to this, the side of the No. 1 container features information on the construction date, the batch reference of the charcoal and information on the contractor responsible for its creation.
Container, A. G., Light, Mk. II[]
The Mk. I design was something of an ad hoc configuration made to quickly get an anti-gas container issued with the Mk. I respirators. The Mk. II design was already in the minds of those involved with the creation of the Mk. I in that it should be filled entirely into a single canister with a back plate closing it off. The contents of the filter is exactly the same as the Mk. I and the general layout of the filter contents remains unchanged. The Mk. II can be identified, aside from the lack of tape, by a lip at the base of the container, meaning the plate on the bottom would sit recessed inside the body.
In 1943, the Mk. II Container saw an upgrade which would see it protected better against prussic acid (hydrogen cyanide), containers with this upgraded marked, on the connical face to the top of the container, with a white dot. In August 1944, a further upgrade to the charcoal mix was introduced to afford better protection against cyanogen chloride, but no further marking was added to the container body, as it was assumed that those concerned with such matters would be able to remember the date of August 1944 and consider all containers beforehand unprotected and those afterwards protected and fit for service.
The Mk. II continued service following the end of the Second World War until about 1956, where its successor, the Mk. III Light Container, fully replaced it for service with the Mk. 6 and 7 Light Respirator.
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Container, A. G., Light, Mk. III[]
The Mk. III Light Container was practically identical to the Mk. I and II in regards to its filling. It consisted of a canister body filled with a diaphragm, a cotton/fabric pad, the charcoal mix, a cotton/fabric pad, another diaphragm, another cotton/fabric pad, the resin-wool, a cotton/fabric pad, one last diaphragm and then the back plate of the container sealing it shut. However, to compensate for the increased flexibility of the rubber mask, the Light Container was made much smaller than the former two designs.
The Mk. III Light Container is roughly 89 mm (3 1/2 inches) in diameter with a weight of 226g, this compared to the 105 mm (4 1/8 inch) diameter and 333g weight of the former Mk. II Light Container, was a clear improvement. In addition to the change in dimensions, it should also be noted that the diaphragms used inside this container are noticably different to those used in all former British Light-type Containers and the on the Mk. III General Civilian Respirator (Small Child Respirator).
It is unclear what caused the design the container to revert to roughly the same diameter of the Mk. II with the introduction of the S6 Respirator in 1958, but it can be assumed that with the need to increase mobility, the idea of widening but shortening the filter may have been desirable at the time. Of course, as respirators began to move back to much more solid shapes, the containers could be made larger without causing the mask to sag.
Whilst Mk. III Containers were issued alongside the Mk. 6 and 7 Light Respirator, it should be noted that Mk. II Containers were still very much in service until at least 1956.