The modern suit Atmospheric diving suit

two divers, 1 wearing tritonia ads , other standard diving dress, preparing explore wreck of rms lusitania, 1935.

although various atmospheric suits had been developed during victorian era, none of these suits had been able overcome basic design problem of constructing joint remain flexible , watertight @ depth without seizing under pressure.

pioneering british diving engineer, joseph salim peress, invented first usable atmospheric diving suit, tritonia, in 1932 , later involved in construction of famous jim suit. having natural talent engineering design, challenged himself construct ads keep divers dry , @ atmospheric pressure, @ great depth. in 1918, peress began working wg tarrant @ byfleet, united kingdom, given space , tools develop ideas constructing ads. first attempt immensely complex prototype machined solid stainless steel.

in 1923, peress asked design suit salvage work on wreck of ss egypt had sunk in english channel. declined, on grounds prototype suit heavy diver handle easily, encouraged request begin work on new suit using lighter materials. 1929 believed had solved weight problem, using cast magnesium instead of steel, , had managed improve design of suit s joints using trapped cushion of oil keep surfaces moving smoothly. oil, virtually non-compressible , readily displaceable, allow limb joints move freely @ depths of 200 fathoms (1,200 ft; 370 m), pressure 520 psi (35 atm). peress claimed tritonia suit function @ 1,200 ft (370 m) although never proven.

in 1930, peress revealed tritonia suit. may had completed trials , publicly demonstrated in tank @ byfleet. in september peress assistant jim jarret dived in suit depth of 123 m (404 ft) in loch ness. suit performed perfectly, joints proving resistant pressure , moving freely @ depth. suit offered royal navy turned down, stating navy divers never needed descend below 90 m (300 ft). in october 1935 jarret made successful deep dive more 90 m (300 ft) on wreck of rms lusitania off south ireland, followed shallower dive 60 metres (200 ft) in english channel in 1937 after which, due lack of interest, tritonia suit retired.

the development in atmospheric pressure suits stagnated in 1940s through 1960s, efforts concentrated on solving problems of deep diving dealing physiological problems of ambient pressure diving instead of avoiding them isolating diver pressure. although advances in ambient pressure diving (in particular, scuba gear) significant, limitations brought renewed interest development of ads in late 1960s.

the jim suit

the tritonia suit spent 30 years in engineering company s warehouse in glasgow, discovered, peress help, 2 partners in british firm underwater marine equipment, mike humphrey , mike borrow, in mid-1960s. umel later classify peress suit a.d.s type , designation system continued company later models. in 1969, peress asked become consultant new company created develop jim suit, named in honour of diver jim jarret.

a jim suit on display @ royal navy submarine museum, gosport

the first jim suit completed in november 1971 , underwent trials aboard hms reclaim in 1972. in 1976, jim suit set record longest working dive below 490 feet (150 m), lasting 5 hours , 59 minutes @ depth of 905 feet (276 m). first jim suits constructed cast magnesium high strength-to-weight ratio , weighed approximately 1,100 pounds (498.95 kg) in air including diver. 6 ft 6 inches (1.98 m) in height , had maximum operating depth of 1,500 feet (457 m). suit had positive buoyancy of 15 50 pounds (6.8 22.7 kg). ballast attached suit s front , jettisoned within, allowing operator ascend surface @ approximately 100 feet (30 m) per minute. suit incorporated communication link , jettisonable umbilical connection. original jim suit had 8 annular oil-supported universal joints, 1 in each shoulder , lower arm, , 1 @ each hip , knee. jim operator received air through oral/nasal mask attached lung-powered scrubber had life-support duration of approximately 72 hours, although actual survival time have been unlikely due thermal transfer through magnesium body.

as technology improved , operational knowledge grew, oceaneering upgraded fleet of jims. magnesium construction replaced glass-reinforced plastic (grp) , single joints segmented ones, each allowing 7 degrees of motion, , when added giving operator great range of motion. in addition, four-port domed top of suit replaced transparent acrylic 1 taken wasp, allowed operator much-improved field of vision. trials carried out ministry of defence on flying jim suit powered surface through umbilical cable. resulted in hybrid suit ability of working on sea bed mid water.

in addition upgrades jim design, other variations of original suit constructed. first, named sam suit (designated a.d.s iii), aluminium model. smaller , lighter suit, more anthropomorphic original jims , depth-rated 1,000 feet (300 m). attempts made limit corrosion use of chromic anodizing coating applied arm , leg joints, gave them unusual green color. sam suit stood @ 6 feet 3 inches (1.91 m) in height, , had life-support duration of 20 hours. 3 sam suits produced umel before design shelved. second, named jam suit (designated a.d.s iv), constructed of glass-reinforced plastic (grp) , depth-rated around 2,000 feet (610 m).