Designed by Robert Davis – the M.D. of Siebe, Gorman & Co. who was later knighted for his services to diving – and submitted for testing by the British Admiralty in 1929, the Submersible Decompression Chamber (SDC) provided welcome relief for surface-supplied divers involved in deep diving operations.
Entering the higher-than-ambient pressurised chamber through a lower hatch – where the helmet was removed and the umbilical hoses disconnected – the diver and his attendant would complete the tediously long decompression schedules while the chamber, with the lower hatch closed, was gradually hauled to the surface.
During 1957 the Royal Navy abandoned surface-supplied deep diving as being too hazardous to the individual diver and concentrated their efforts instead on developing the principle of diving from a manned underwater capsule – the diving bell – from which a diver could emerge at the operating depth on the end of a short umbilical whilst closely attended and observed from within the capsule.
It’s a concept that’s now employed on a daily basis in the offshore oil and gas industries by saturation divers when travelling from their ‘home’ in a Deck Decompression Chamber Facility to the sub-sea worksite when lengthy – and usually deep – submersions are required in order to complete a task.
A principle that’s now being adopted by exploration divers facing lengthy in-water decompression schedules, there’s an excellent article on decompression habitats, by Andy Pitkin, in the November issue of G.U.E.’s on-line, ‘In-Depth’ magazine at:
(Mono Images of Submerged Decompression Chamber from, ‘Deep Diving And Submarine Operations’, by Robert H. Davis.)