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 Siebe Gorman’s D.S.E.A

Date: 19 January 2003

Davis Submerged Escape Apparatus 

JW. Bech


Siebe Gorman and Co. Ltd



Davis Submerged Escape Apparatus


Land of origin



Special Note: 

Most wide spread escape apparatus 


User group



Part no:



Working principle

Manual operation


Gas type



Cylinder volume

~ 0,46 litrs


Max. cylinder pressure

120 bar (56 litres)


Material of cylinder



Counterlung inspire

On the chest


Counterlung exhale



Dive time duration



Operating temperature



Magnetic signature



Weight ready to use in Air



Weight ready to use in water




330 ft

(time limited)

Scrubber material










Scrubber+ Bottle on the chest



Single hose with shut  off valve






Exhaust valve mounted in front of the wearer on the left shoulder.











If you have any information to add this sheet please mail it to jw.bech@quicknet.nl References to source and names will always be added!  


Info found: R.H. Davis, Deep Diving and Submarine operations


Origin: http://www.therebreathersite.nl






Description of the Apparatus

The apparatus consists of  an insertion rubber breathing and buoyancy bag, inside which is arranged a canister containing a chemical for the absorption of the wearer's exhaled carbonic acid gas (CO2). In a pocket at the lower extremity of the bag is carried a steel cylinder containing about 56 litres of oxygen compressed to 120 atmospheres, the cylinder being provided with a control valve and connected by a tube to the breathing bag. The opening of the cylinder valve admits oxygen to the breathing bag and charges it to a pressure equal to that of the surrounding water at whatever depth the apparatus is being used.

The wearer is thus able to breathe in a normal manner.

The canister of chemical absorbent inside the breathing bag is connected by means of a flexible corrugated tube to a mouthpiece; breathing is carried out by the mouth only, the nose being closed by a clip . Goggles with splinterless glasses are also provided.

In order to conserve as much as possible the supply of oxygen in the cylinder , means are provided whereby oxygen can be admitted to the bag from an external source of supply-for example, a charging manifold connected to a large storage cylinder of oxygen installed in the compartments of the submarine. These consist of a tube (H) connected to the bag and provided at its outer end with a non-return inlet valve . This tube is connected to the external source of oxygen and the latter is turned on until the bag is filled sufficiently to enable the wearer to breathe comfortably.

A third and last source of supply is provided in the shape of two small steel capsules of oxygen called "Oxylets", mounted inside the breathing bag. These capsules are provided with break-off necks and the oxygen is released from them by gripping (one at a time) in the hands (through the breathing bag) and wrenching sharply, so breaking the neck.

The breathing bag is provided with an automatic non-return air release valve (K) which allows air to escape from the bag as the user ascends to the surface and decreas­ing pressures. A "gag" device is provided so that the wearer can close this valve on reaching the surface, thus retaining the air in the breathing bag, the latter then serving as a lifebelt.

A two-way tap (M) is provided in the mouthpiece. This is kept closed when the apparatus is not in use, in order to prevent access of air to the chemicals in the canister. It should be closed when the wearer reaches the surface, the mouthpiece and noseclip being removed.

Should the main breathing bag become deflated while the wearer is floating on the surface, it may be refilled by taking the mouthpiece into the mouth, opening the cock and blowing into the bag. The cock should be shut again before the mouthpiece is removed from the mouth.

The apparatus is provided with an adjustable neck-strap and with adjustable waist-­straps. These straps should be adjusted by the wearer beforehand to suit himself, so that the apparatus is always ready for use in emergency without further adjustment.

. The Emergency Buoyancy Bag . This is a small additional bag formed on the front of the main breathing bag. lts object is to ensure that the wearer of the apparatus shall remain afloat on reaching the surface-even if he has lost all the air from the breathing bag.

The emergency bag is inflated by means of an “Oxylet” situated inside it, and broken by grasping the metal holder (situated at the bottom right hand side) and bending this until the copper seal is broken. The emergency bag should be inflated before leaving the submarine.

 .The Speed-Retarding Vane. This is a rubber extension, similar to an apron, which should be unrolled and held out by the wearer in the horizontal position when he is ascending through the water. The vane set up a considerable resistance tot the wearer’s passage through the water and greatly retards the speed of his ascent.








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