This Respirator, though mostly considered to be a prototype of the 1941 proposed Light Anti-Gas Respirator was a mask used during two Biological Weapons tests by the Microbiological Research Department of Porton Down in 1952 and 1953. These operations, codenamed Cauldron and Hesperus, involved the testing of three pathogens on animals, not far from the Isle of Lewis (Outer Hebrides, Scotland, UK).

The mask itself is a modification made to Microphone Variants of the Mk. IV General Service Respirator and the Mk. V General Service Respirator. The modification consists of the blanking of the inlet tubing and the mounting of a container mount by means of incision, insertion and clamping.

It is unclear whether or not this design was ever used during 1941 as a prototype to the Light Anti-Gas Respirator, however, there is no documentation available amongst the collections and archives of collectors, nor is there any reference at the National Archives specifically, however, documents concerning the production of the Light Anti-Gas Respirator may confirm whether or not this design was ever trialed in 1941 or, possibly earlier.

What we do know is that this Respirator was used by scientists during these two controversial operations in 1952 and 1953.

If you use this information, please credit the user/collector Baroque4Days and/or those responsible for the photographs below.

Design & Variants Edit

Though, the name of this respirator is currently unknown, this respirator can be based on either the Mk. IV or Mk. V General Service Respirator facepiece, with seemingly an indiscriminate mix during the 1952 tests. This respirator is created fairly easily and has, for this reason, been reproduced by some collectors.

To create this respirator, the wire and tape connecting the hose to the metal tubing are remove and a rubber blanking plug is then taped and wired in the place of the hose. This modification prevents the wearer from inhaling through the original inlet, whilst allowing the wearer to still exhale without obstruction. Once this is done, depending on the variant, an aperture is either cut or will already be cut into the microphone mount on the left-hand side of the faceblank. Much like how the No. 1 and No. 2 Respirator Microphones were attached, a special-made container mount with a tube attached to it would be inserted into the hole and attached via a clamp of some kind around the base of the stump.

These two modifications would complete the respirator and allow the unnamed partical filter, seen in many 1950s Nuclear and Biological tests, to be screwed on to the outside of the mask. The result of this would be essentially the same as that of the Light Anti-Gas Respirator, only a little cheaper. It is unclear why the Light Anti-Gas Respirator was not used in the place of this design.

Potential Porton 1950s Op Cauldron - Danny McGurk

from the collection of Danny McGurk.

Aside from the standard design, it seems that there was a much more refined version of this mask, based on a facepiece found by British collector Danny McGurk. As you can see from the picture, also taken by McGurk, there is no tubing to attach a hose to. This mask, as it is in the photograph, would be useless and would not allow the wear the breathe unless a container mount was attached to the side. Note that there is an aperture in the typically sealed microphone stump.

Details of Operation Cauldron, 1952 & Hesperus, 1953 Edit

In 1951, the Microbiological Reserarch Department (MRD) of Porton Down requested that Brucellosis and Plague be tested on live animals in an open air environment. The idea was to test how effective a bomb or spray-method could be at affecting live targets. Once passed by Porton, and later by the Scottish Government, the MRD were free to carry out this test just off the coast of the Outer Herbridean Island, Lewis.

A pontoon was suspended in the water to prevent the requirement of a groundbase. This also ended up saving the researchers from requiring an additional ship and allowed the test to be completed with little more than this floating platform and a single vessle. Monkeys and Guinea Pigs were placed inside sealed boxes which were then stacked and then moved by trolley to be ordered in a slight crescent shape facing the direction of the blast or spray.

Once the bio weapon was released, either in the form of a spray or bomb, the Monkeys/Guinea Pigs were taken back for evaluation. The purpose of the test was to see how high infection rate would be and how effective the method of releasing the two pathogens would be in a fairly windy, open-air environment. It is unclear whether or not the idea was to use these weapons against enemy naval forces, considering the location of the test.

In 1953, testing of the Plague was scrapped and, along with Brucellosis, Tularaemia was used. This Operation was codenamed Hesperus and is often considered to be, essentially, the same as Cauldron.

In 1994, an PM requested that the details of these two tests be released to the public, following concern from his constituants, however, due to the nature of the tests, the argument that it would be against national security was put forth by Dr Pearson, the Director-General of the Chemical Biological Defence Establishment, and a vague statement was gave about the safety of the public, careful planning and the three pathogens used during the tests. By 2008, the Ministry of Defence was ruled agaisnt and a 47 minute video, recorded to sumarise the test, was released. This video can be found here and clearly shows the use of these modified General Service Respirators.

It is worth noting that the wikipedia page on Operation Cauldron mentions a civilian ship which ignored warnings and passed into the area during the test, supposedly sailing through the cloud of pathogens. They were monitored for some time from afar before it was assumed that the sailors were unaffected.

Potential Relation to the Light Anti-Gas Respirator Edit

Some of the older British collectors have mentioned a 1938 proposed Respirator known as the "Self-Contained Respirator" which was supposedly a modification of the Mk. IV or V General Service Respirator to meet the requirements of the Special Services. Due to the wording of this speculation, it is unclear whether or not this was a confusion between the original name for the Civilian Duty Respirator, the Special Service Respirator of 1934, and/or the original name of the Light Anti-Gas Respirator, the Special Light Respirator of 1941.

It is entirely possible that this respirator was conceptalised prior to the 1941 request for a lightweight respirator for assault troops or that it was something designed, and potentialled trialled, during the creation of the Light Anti-Gas Respirator. It is important to note that the Light Anti-Gas Respirator was requested in 1941 and also at least two, but possibly three, finalised variants of the LAG were actually also released and issued in 1941 as well. This means that trials would have been fairly constrained by time which would make sense of why Porton may have merely attempted to modify a General Service Respirator to begin with.

However, despite the plausibility of this theory, it is absolutely unproven that these respirators existed before the 1952 biological weapon trials in Scotland, yet, it is also unlikely that these respirators were only created for a single year of testing. As per usual, I will be on the look out for further information and believe to have a good three leads which may result in the discovery of new information which may prove or disprove their 1940s existance.

References Edit

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