page_title: Siebe Gorman CDBA
section_title: Other similar rebreathers
hierarchical_section_title: Siebe Gorman CDBA / Other similar rebreathers
caption_attribution_description: English: 2 frogmen with Siebe Gorman SCBA (or similar) 1950's-type rebreathers.
context_page_description: The Clearance Divers Breathing Apparatus is a type of rebreather made by Siebe Gorman in England.
  The British Royal Navy used it for many years. It was for underwater work rather than for combat diving. The main oxygen cylinders are on the diver's back. The oxygen cylinders at the front of the diver are for bailout. In its basic mode it was an oxygen rebreather; but some of the cylinders could be replaced by diluent cylinders for nitrox mode, and then the set was sometimes called CDMBA. The Royal Navy was using nitrox from 1944, but did not reveal its nitrox techniques, and in the 1960s and afterwards civilian divers had to retread the same ground and develop nitrox diving independently. In later years it was called DSSCCD from "Diving Set, Self-Contained, Clearance Diver".
context_section_description: British "frogman's" sets used the same shape of counterlung as the CDBA but different cylinders. One type was the "Swimmer Canoeists Breathing Apparatus" (SCBA), which had oxygen cylinders on the back, vertically for better streamlining in swimming, the oxygen connections thinner, and no cylinders on the front, leaving the diver's lower front uncluttered for climbing in and out of small boats. The SCBA gave 90 minutes dive duration with no reserve. In mixture (nitrox or heliox) mode it was called SCMBA. An old photograph seems to show the cylinders (and perhaps also the weights) in a tied or laced canvas casing rather than held on with metal clamps, and a rectangular fullface mask as with the CDBA. There is a British armed forces manual about the SCBA, dated 1984 as if the SCBA was still in use then, showing separate eyes-and-nose mask and strapped-in mouthpiece and no canvas pouch, and separate sport-type weight belt with buckle-shaped weights all at the back. The design of the Swimmer Canoeists Breathing Apparatus likely changed down the years.
  The LOSE (Lightweight Oxygen Swimmers Equipment), a diving rebreather formerly made by Siebe Gorman, was similar to a Swimmer Canoeist's Breathing Apparatus including the cylinder backpack.
  Other British frogmen's sets had no back cylinders and one or more big cylinders across the belly: one of these modes was the UBA (Underwater Breathing Apparatus).
caption: 2 frogmen with Siebe Gorman SCBA (or similar) 1950's-type rebreathers
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