1943. Birth of the ‘Sja 3’ helmet, the new standard 3 bolt diving helmet.

1950. The 3 bolt ‘UVS50’ helmet made at ‘Factory Number 3’ in Leningrad

‘Sja-3’ helmet number 80 - dated 1944

Sja-3 helmet with not known number - dated 1945

Sja-3 helmet number 232 - dated 1946

‘Sja-3’ helmet number 347 dated - 1947 ( the year the badge was introduced )

Tinned ‘Sja-3’ helmet number 371 with breastplate number 349

During and after WW2, books were published by the ASU VMF, which was later renamed the ASS VMC ( both names stand for the Soviet Navy which had assimilated the EPRON institute in 1942 ) These books contain several articles on recirculation helmets and oxygen decompression after deep-diving. Diving experiments were carried out during the 1930's and the detailed results were published in 1945. However no description is given regarding the diving apparatus used during the experiments. Russian navy diving manuals from 1945 and 1946 only show western manufactured equipment such as the MkV mixed gas, DESCO Buie helmets, and the Draeger DM20 and DM40 helmets. This equipment is referred to as the "Injector Skafanders".

WW2 Publications which refer to mix gas diving

1948. Tests with the SKD ‘Injector Skaphander’

The first ‘Injector Skafander’ manufactured by the Russians appears to be the 'SKD' apparatus. SKD stands for 'Skafandr Kislorod Dekompressia' ( it translates as: 'Scaphander Oxygen Decompression' ) WW2 had just ended and the post-war period left a great deal of underwater work for divers in Russia. To this end the Russian Navy ordered the SKD apparatus from 'Factory Number 3' in Leningrad. The SKD apparatus allowed for quicker diver decompression after a deep dive. However it was never very popular among the divers who preferred normal helmets and normal rates of decompression ( or surface decompression facilities instead ) The SKD helmet was just a standard 'Sja-3' helmet fitted with a different breathing system. An experimental SKD helmet does exist with the following inscription stamped into the 3-bolt ring: ‘EXPERIMENT NR 19 FACTORY Nr3 1948’. In the Injector housing are engraved in large letters: SKD. The only manual I have came across is dated 1953 and describes the SKD1 and SKD2 helmets. An interesting feature on this prototype SKD helmet is the combined 'air and communication connector' which became the new standard feature on all helmets from 1950 onwards. Photographs David L.Dekker.

1954. The Helium Oxygen Mix apparatus ‘GKS3’ is introduced.

'GKS3' stands for 'Gelii Kislorod Smers Model 3' (Helium Oxygen mix gas model 3). The GKS3 helmet was an apparatus intended for deep-diving using a breathing gas which was a mixture of helium and oxygen. It's injector was attached at the same location on the helmet as it was on the 'SKD' prototype ( shown above: in front of the divers mouth ) American helmets have the injector to the right on the back of the helmet ( just in front of the CO2 absorbent canister ) German Draeger mix gas apparatus have the injector placed in the backpack ( just after the CO2 absorbent canister ) The maximum depths the Russian apparatus were to be used was 200 meters ( according to the manual ), but the Russian navy occasionally used them down to 300 meters. The earliest diving manual I have which describes the GKS3 apparatus was printed in 1954 and published in 1955. This Russian mixed gas system was the best designed, deep-diving apparatus in the world at that time. Photograph David L.Dekker collection.

1957. The Air Oxygen Mix apparatus ‘VKS57’ is introduced.

For diving depths of between 60-100 meters a diving apparatus was developed called the 'VKS57' which stands for ‘Vozduch Kislorod Smers model 1957’ ( translates as: Air-Oxygen mix gas model 1957 ) The helmet is basically a normal ventilated diving helmet except the breastplate bolts are taller as an extra ring is added between the breastplate and bonnet: 'the ring with the incorporated injector system'.

The helmet has the same basic design as the SKD of 1948 and the GKS3 of 1954 except that the venturi system is built into a separate ring and not built directly onto the helmet. The bag attached to the hand-grip on top of the helmet holds the connector for the communications. This same helmet ( without the venturi system ) appeared as a ‘ventilated helmet’ in 1963 and was the successor to the UVS50 helmet. The telephone space next to the front window and the hand-grip on the helmet top became the new standard for the air-oxygen diving helmet which was called UVS50m. Photographs David L.Dekker

Photograph above: a diver is ready to descend in a VKS57 helmet. This is a well organized diving site from the look of the other diving apparatus arranged in the background.

According to the Russian Navy Diving Manual of 1968, the WKS57 was operated on an air-oxygen mixture for diving depths to 60 meters, then switched to an air-helium mixture for diving depths between 60 and 100 meters. The WKS57 appears to have been produced in small quantities. The last Russian Navy diving manual I came across which had a description of this helmet was published in 1973. However, the GKS3-M helmet was around a lot longer and the most recent one I have come across was manufactured in 1982. Photograph David L.Dekker collection.

Above scan: the workings of the 'VKS57' apparatus which is more or less the same as the 'GKS3m' except for the missing bailout set / front-weight. Diving manual David L.Dekker collection. The working of the GKS3m is explained below.

The first manual I have found that describes the 'GKS3m' apparatus was published in 1962. The GKS3-M is the modified version of the GKS3 apparatus but the only real modification was a faster 'venturi'. The old helmet had 6-cycles per minute while the new one had 10-cycles per minute. Photographs David L.Dekker

1962. The Helium Oxygen Mix apparatus ‘GKS3m’ is introduced.

The GKS3m diving apparatus displayed at a navy diving school in Russia. Photograph David L.Dekker collection.

The left-hand illustration shows how the 'venturi' works: The gas arrives from the surface through hose (2) at the chest weight which houses the bail-out set. There is a 'selector' (3) incorporated in the chest-weight which can be switched between the surface demand gas supply (or in case of a problem) to the gas supply in the two small tanks (5) that are incorporated inside the chest-weight. When the surface supply is selected the gas goes through hose (1) to the back, left side of helmet where a copper tube carries it to the injector (6). The gas flows at high speed to the opening in front of the divers mouth which creates a similar effect to that of a paint spray-gun: i.e. the gas inside the helmet is sucked along with this high speed flow (just as paint is sucked along in the airstream of a paint spray-gun). The gas flows to the back of the helmet where it is connected to the scrubber canister (8) which is worn on the diver's back. Here, the CO2 is filtered from the gas, and the refreshed gas is carried back by 'venturi' into the helmet via the right-hand hose and back into the helmet. In case of a problem with the injector the bypass can be used by pushing handle (4) on the chest-weight: the gas will then travel through hose (7) to the back right of the helmet and instead will pass directly into the helmet through the hole of the injector (6) in front of the divers mouth

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The right-hand illustration shows the injector: the gas arrives either for the 'venturi' or for the bypass through tubes (5). Hole 3 is the opening where either the exhaled gas is sucked away, or where the bypass gas is shot into the helmet. Tube (1) is where the fresh gas together with the exhaled gas are carried through to the canister on the divers back to be filtered.