Early designs In 1715, the British inventor
John Lethbridge constructed a "diving engine". Essentially a wooden barrel about in length with two holes for the diver's arms sealed with leather cuffs, and a viewport of thick glass. It was reportedly used to dive as deep as , and was used to salvage substantial quantities of
silver from the wreck of the
East Indiaman , which had sunk in 1719 off the
Cape Verde islands. A similar design made of copper was used by Jacob Rowe on the same salvage contract. The first armored suit with real joints, designed as leather pieces with rings in the shape of a spring (also known as accordion joints), was designed by the Englishman W. H. Taylor in 1838. The diver's hands and feet were covered with leather. Taylor also devised a ballast tank attached to the suit that could be filled with water to attain negative
buoyancy. While it was patented, the suit was never actually produced. It is considered that its weight and bulk would have rendered it nearly immobile underwater. Lodner D. Phillips designed the first completely enclosed ADS in 1856. His design comprised a barrel-shaped upper torso with domed ends with ball and socket joints in the articulated arms and legs. The arms had joints at shoulder and elbow, and the legs at knee and hip. The suit included a ballast tank, a viewing port, entrance through a
manhole cover on top, a hand-cranked propeller, and rudimentary manipulators at the ends of the arms. Breathing air was to be supplied from the surface via hose. There is no indication that Phillips's suit was ever constructed. The first properly anthropomorphic design of ADS, built by the
Carmagnolle brothers of
Marseille, France in 1882, featured rolling convolute joints consisting of closely fitting concentric spherical sections sealed by watertight cloth membranes. The suit had 22 of these joints: four in each leg, six in each arm, and two in the torso. The helmet had 25 individual glass viewports spaced at the average separation of the human eyes. Weighing , the Carmagnole ADS never worked properly and its joints never were entirely waterproof. It is now on display at the
French National Navy Museum in Paris. Another design was patented in 1894 by the inventors John Buchanan and Alexander Gordon from
Melbourne, Australia. The construction was based on a frame of spiral wires covered with waterproof material. The design was improved by Alexander Gordon by attaching the suit to the helmet and other parts and incorporating jointed
radius rods in the limbs. This resulted in a flexible suit which could withstand high pressure. The suit was manufactured by British firm
Siebe Gorman and trialed in Scotland in 1898. The American designer Macduffee constructed the first suit to use ball bearings to provide joint movement in 1914; it was tested in
New York to a depth of , but was not very successful. A year later, Harry L. Bowdoin of
Bayonne, New Jersey, made an improved ADS with oil-filled rotary joints. Each joint has a small duct to its interior to allow equalization of pressure. The suit was designed to have eighteen joints: four in each arm and leg, and one in each thumb. Four viewing ports and a chest-mounted lamp were intended to assist underwater vision. There is no evidence that Bowdoin's suit was ever built, or that it would have worked if it had been. Atmospheric diving suits built by
Neufeldt and Kuhnke of Germany were used during the salvage of gold and silver bullion from the wreck of the British ship
SS Egypt, an 8,000 ton
P&O liner that had sunk in May 1922. The suit was relegated to duties as an observation chamber at the wreck's depth of , and was successfully used to direct mechanical grabs which opened up the bullion storage. In 1917,
Benjamin F. Leavitt of
Traverse City, Michigan, dived on the
SS Pewabic which sank to a depth of in
Lake Huron in 1865, salvaging 350 tons of copper ore. In 1923, he went on to salvage the wreck of the British schooner
Cape Horn which lay in of water off
Pichidangui, Chile, salvaging $600,000 worth of copper. Leavitt's suit was of his own design and construction. The most innovative aspect of Leavitt's suit was the fact that it was completely self-contained and needed no umbilical, the breathing mixture being supplied from a tank mounted on the back of the suit. The breathing apparatus incorporated a
scrubber and an oxygen
regulator and could last for up to a full hour. In 1924 the
Reichsmarine tested the second generation of the Neufeldt and Kuhnke suit to , but limb movement was very difficult and the joints were judged not to be
fail-safe, in that if they were to fail, there was a possibility that the suit's integrity would be violated. However, these suits were used by German armored divers during
World War II and were later taken by the
Western Allies after the war. From 1929 to 1931 two atmospheric pressure one-person submersible "suits" designed by Carl Wiley were used in the successful salvage of the steamship
Islander which sank in the
Stevens Passage near
Juneau, Alaska on 15 August 1901, with a large amount of gold dust in the cargo. The suits operated at a maximum depth of . They were each equipped with a mechanical arm with a grasping claw at the end operated from inside the suit. The suits were capable of traversing a hard, reasonably smooth substrate on wheels, and were used to place the steel cables used to raise the wreck by
tidal lift (with an tide range) under a catamaran barge in stages, while it was towed to shallow water. The suits had electrical power, and the diver/pilot used an oxygen rebreather. These suits have also been described as diving bells and observation chambers, as they do not match the usual definition of an atmospheric diving suit, but they were more than just observation chambers, being capable of work, and were independently mobile, so do not match the usual definition of a diving bell either. They were an unusual type of tethered crewed submersible. In 1952,
Alfred A. Mikalow constructed an ADS using ball and socket joints, specifically for the purpose of locating and salvaging sunken treasure. The suit was reported to be capable of diving to depth and was successfully used to dive on the wreck of
SS City of Rio de Janeiro near
Fort Point, San Francisco at a depth of . Mikalow's suit had various interchangeable instruments which could be mounted on the end of the arms in place of the original manipulators. It carried seven 90-cubic foot high pressure cylinders to provide breathing gas and control buoyancy. The ballast compartment covered the gas cylinders. For communication, the suit used
hydrophones.
The modern suit Peress' Tritonia Although various atmospheric suits had been developed during the
Victorian era, none of these suits overcame the basic design problem of constructing a joint which would remain flexible and watertight at depth without seizing up under pressure. Pioneering British diving engineer,
Joseph Salim Peress, invented the first truly usable atmospheric diving suit, the
Tritonia, in 1932 and was later involved in the construction of the famous
JIM suit. Having a natural talent for engineering design, he challenged himself to construct an ADS that would keep divers dry and at atmospheric pressure, even at great depth. In 1918, Peress began working for WG Tarrant at
Byfleet, United Kingdom, where he was given the space and tools to develop his ideas about constructing an ADS. His first attempt was an immensely complex prototype machined from solid
stainless steel. In 1923, Peress was asked to design a suit for salvage work on the wreck of
SS Egypt which had sunk in the
English Channel. He declined, on the grounds that his prototype suit was too heavy for a diver to handle easily, but was encouraged by the request to begin work on a new suit using lighter materials. By 1929 he believed he had solved the weight problem, by using cast magnesium instead of steel, and had also managed to improve the design of the suit's joints by using a trapped cushion of oil to keep the surfaces moving smoothly. The oil was virtually non-compressible and readily displaceable, which would allow the limb joints to move freely even under great pressure. Peress claimed the Tritonia suit could function at , where the pressure was , although this was never proven. In 1930, Peress revealed the Tritonia suit. By May it had completed trials and was publicly demonstrated in a tank at
Byfleet. In September Peress' assistant
Jim Jarret dived in the suit to a depth of in
Loch Ness. The suit performed perfectly, the joints proving resistant to pressure and moving freely even at depth. The suit was offered to the
Royal Navy which turned it down, stating that Navy divers never needed to descend below . In October 1935 Jarret made a successful deep dive to more than on the wreck of the off south Ireland, followed by a shallower dive to in the
English Channel in 1937 after which, due to lack of interest, the Tritonia suit was retired. The development in atmospheric pressure suits stagnated in the 1940s through 1960s, as efforts were concentrated on solving the problems of deep diving by dealing with the physiological problems of ambient pressure diving instead of avoiding them by isolating the diver from the pressure. Although the advances in ambient pressure diving (in particular, with
scuba gear) were significant, the limitations brought renewed interest to the development of the ADS in the late 1960s.
The JIM suit The
Tritonia suit spent about 30 years in an engineering company's warehouse in
Glasgow, where it was discovered, with Peress' help, by two partners in the British firm Underwater Marine Equipment, Mike Humphrey and Mike Borrow, in the mid-1960s. UMEL would later classify Peress' suit as the "A.D.S Type I", a designation system that would be continued by the company for later models. In 1969, Peress was asked to become a consultant to the new company created to develop the JIM suit, named in honour of the diver Jim Jarret. The first JIM suit was completed in November 1971 and underwent sea trials from in early 1972. In 1976, it set a record of five hours and 59 minutes for the longest working dive below , at a depth of . The first JIM suits were constructed from cast magnesium for its high strength-to-weight ratio and weighed approximately in air, including the occupant. They were in height and had a maximum operating depth of . The suit had a positive buoyancy of . Ballast was attached to the suit's front and could be jettisoned from inside, allowing the suit to ascend to the surface at approximately . The suit also incorporated a communication link and an umbilical connection that could be released by the diver. The original JIM suit had eight annular oil-supported universal joints, one at each hip, knee, shoulder and lower arm. The JIM operator received air through an oral/nasal mask that attached to a lung-powered scrubber that had a life support duration of approximately 72 hours. Operations in arctic conditions with water temperatures of for over 5 hours were successfully carried out using woolen thermal protection and neoprene boots. In water the suit was reported to be uncomfortably hot during heavy work. on display at the
Royal Navy Submarine Museum, Gosport As technology improved and operational knowledge grew, Oceaneering upgraded their fleet of JIMs. The magnesium construction was replaced with
glass-reinforced plastic (GRP) and the single joints with segmented ones, each allowing seven degrees of motion, and when added together giving the operator a very great range of motion. In addition, the four-port domed top of the suit was replaced by a transparent acrylic dome as used on WASP, which provided a much better field of vision. Trials were also carried out by the
Ministry of Defence on a flying Jim suit powered from the surface through an umbilical cable. This resulted in a hybrid suit with the ability of working on the sea bed as well as mid water. In addition to upgrades to the JIM design, other variations of the original suit were constructed. The first, named the SAM Suit (designated A.D.S III), was a completely aluminium model. A smaller and lighter suit, it was more anthropomorphic than the original JIMs and was depth-rated to . Attempts were made to limit corrosion by the use of a chromic anodizing coating applied to the arm and leg joints, which gave them an unusual green color. The SAM suit stood at in height, and had a life support duration of 20 hours. Only three SAM suits would be produced by UMEL before the design was shelved. The second, named the JAM suit (designated A.D.S IV), was constructed of
glass-reinforced plastic (GRP) and was depth-rated for around .
WASP , UK The WASP atmospheric diving system is partway between a one-person submersible and an atmospheric diving suit, in that there are articulated arms which contain and are moved by the operator's arms, but the operator's legs are contained in a rigid housing. Mobility is provided by two vertical and two horizontal foot-switch controlled electrical
marine thrusters. Operating depth was quoted as WASP is high, wide, and front to back. Ballasted weight in air approximately , for neutral buoyancy in water, but buoyancy can be increased by up to during operation, and ballast can be jettisoned in an emergency. WASP is transported on a support frame. ==Current suits==