JIM suit
Encyclopedia
The JIM suit is an atmospheric diving suit
Atmospheric diving suit
An atmospheric diving suit or ADS is a small one-man articulated submersible of anthropomorphic form which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere...

 (ADS), which is designed to maintain an interior pressure of one atmosphere despite exterior pressures, eliminating the majority of physiological dangers associated with deep diving. Because there is no need for special gas mixtures, and there is no danger of nitrogen narcosis
Nitrogen narcosis
Narcosis while diving , is a reversible alteration in consciousness that occurs while scuba diving at depth. The Greek word ναρκωσις is derived from narke, "temporary decline or loss of senses and movement, numbness", a term used by Homer and Hippocrates...

 or decompression sickness
Decompression sickness
Decompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...

 (the 'bends'); the occupant does not need to decompress when returning to the surface. It was invented in 1969 by Mike Humphrey and Mike Borrow, partners in the English firm Underwater Marine Equipment Limited (UMEL), assisted by Joseph Salim Peress
Joseph Salim Peress
Joseph Salim Peress , was a pioneering British diving engineer, inventor of one of the first truly usable atmospheric diving suits, the Tritonia, and was involved in the construction of the famous JIM suit....

, whose Tritonia atmospheric diving suit
Atmospheric diving suit
An atmospheric diving suit or ADS is a small one-man articulated submersible of anthropomorphic form which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere...

 acted as their main inspiration. The suit was named after Jim Jarrett, Peress' chief diver.

History

The petrochemical
Petrochemical
Petrochemicals are chemical products derived from petroleum. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as corn or sugar cane....

 industry was unwilling to finance their research, but a grant was obtained from the British government, and a new company, DHB Construction (for Dennison, Hibberd and Borrow), was formed to develop the suit. The first JIM suit was completed in November 1971 and underwent initial trials aboard HMS Reclaim
HMS Reclaim
HMS Reclaim was a deep diving and submarine rescue vessel of the British Royal Navy. She was originally intended to be the King Salvor-class ocean salvage vessel Salverdant and was fitted with specialised equipment including underwater television cameras and sonar and echosounding apparatus...

 in early 1972. Two dives were conducted to depths in excess of 400 ft (121 m), and were limited only by the depth of the ambient divers providing support. Further development and testing continued until March 4, 1974, when Mike Humphrey conducted a chamber dive to the equivalent of 1,000 ft (300 m). The US Navy Experimental Diving Unit
United States Navy Experimental Diving Unit
The United States Navy Experimental Diving Unit is the primary source of diving and hyperbaric operational guidance for the US Navy...

 conducted tests in 1976.

In spite of the successful tests, the offshore petroleum industry still expressed little interest in the suit and it was not until 1975, when Oceaneering acquired DHB Construction and exclusive rights to the application of JIM suits in the oilfields, that the suit achieved success. This did not however please the British government, who after contributing money to the suit's development, did not want to see it being "given" to an American company over a British one. However, at the time, British diving concerns, most notably 2W, doubted the suit's abilities and therefore passed on purchasing the operating rights.

Its first commercial deployment was in 1974, when JIM suits were used in the recovery of lost oil tanker anchor chains in a Canary Islands harbor. In 1976 the JIM suit was used for a series of four dives on PanArtic's Hecla M25 well which were made through a hole cut in an ice floe 16 feet (5 m) thick, on which the rig was positioned, the first dive setting a record for the longest working dive below 490 feet (149 m), five hours and 59 minutes at a depth of 905 feet (275 m). In 1979, oceanographer
Oceanography
Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean...

 Sylvia Earle
Sylvia Earle
Sylvia Alice Earle is an American oceanographer. She was chief scientist for the U.S. National Oceanic and Atmospheric Administration from 1990–1992. She is a National Geographic explorer-in-residence, sometimes called "Her Deepness" or "The Sturgeon General".-Education and career:Earle received a...

 set a human depth record of 1250 feet (381m) using a JIM suit.

The Arctic dives of 1976 proved that the JIM was capable of performing oilfield operations in very cold and very deep water; the average water temperature at the wellhead was measured at -1.6C (29°F), while the average internal suit temperature was about 10C (50°F). The operators needed no more than a heavy woolen sweater for thermal protection. The following year the JIM suit was used on over 35 jobs with an average duration of over two hours and in depths varying from 300 to 1,130 feet (100 to 394 m), and by 1981, 19 JIM suits had been produced.

The JIM suit and its variations enjoyed great success in the offshore oil industry for many years, although their effectiveness was hampered by the unwillingness of oil companies to install walkways around submerged sections of oil platforms. An experimental thruster pack that would connect to the existing JIM models was designed, but the suit gradually fell out of use with Oceaneering as their new WASP suit, a mid-water vehicle, became the favourite of contractors. The JIMs were still used by the company during the 1980s, including in a joint SAM and WASP recovery of a Wellington Bomber from Loch Ness in 1986, and were often used as back-up standby units for the rapidly-advancing WASP suit. By 1990, the JIM suit was no longer commercially operated. Today, some of them may be viewed at museums across the world, along with many lightweight replica versions.

The JIM Suit is, perhaps, best known to the general public for its appearance in the James Bond
James Bond
James Bond, code name 007, is a fictional character created in 1953 by writer Ian Fleming, who featured him in twelve novels and two short story collections. There have been a six other authors who wrote authorised Bond novels or novelizations after Fleming's death in 1964: Kingsley Amis,...

 film For Your Eyes Only
For Your Eyes Only (film)
For Your Eyes Only is the twelfth spy film in the James Bond series and the fifth to star Roger Moore as the fictional MI6 agent James Bond. It marked the directorial debut of John Glen, who had worked as editor and second unit director in three other Bond films. The screenplay by Richard Maibaum...

, although it played a larger role in the 1989 sci-fi/horror film DeepStar Six
Deepstar Six
DeepStar Six is an American 1989 science fiction horror film about the struggles of the crew of an underwater military outpost to defend their base against the attacks of a monster ....

.

Specifications

Joseph Peress' Tritonia Diving Suit was the starting point for the design of the JIM suit, manufactured from cast magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

 alloy and first successfully tested in September 1930 by Jim Jarret. Following a dive on the wreck of the RMS Lusitania
RMS Lusitania
RMS Lusitania was a British ocean liner designed by Leonard Peskett and built by John Brown and Company of Clydebank, Scotland. The ship entered passenger service with the Cunard Line on 26 August 1907 and continued on the line's heavily-traveled passenger service between Liverpool, England and New...

 in 1935, Peress attempted to sell the Tritonia to the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 and initial sea trials were carried out, but the offer was rejected when it was decided by the Admiralty
Admiralty
The Admiralty was formerly the authority in the Kingdom of England, and later in the United Kingdom, responsible for the command of the Royal Navy...

 that Royal Navy divers had no reason to dive to the depths it was capable of. The suit was later retired, and eventually found its way to a junk shop where it would be discovered by Mike Humphrey and Mike Borrow in the mid-1960s. UMEL would later class Peress' suit as the "A.D.S Type I", a designation system that would be continued by the company for later models.

The first UMEL JIM suits, classified as A.D.S II, were constructed from cast magnesium for its high strength-to-weight ratio and weighed approximately 1,100 pounds (498.95 kg) in air including the diver. They were 6 ft 6 inches (1.98 m) in height, 3 ft 5 in (1.04 m) in width, 3 ft 1 in (94 cm) in side width and had a maximum operating depth of 1,500 feet (457 m). Corrosion problems were countered through surface preparation and coating. The suit had a negative buoyancy of 15 to 50 lb (6.8 to 22.7 kg). Ballast was attached to the suit's front and could be jettisoned from within, allowing the operator to ascend to the surface at approximately 100 feet (30 m) per minute. The suit also incorporated a communication link and a jettisonable umbilical connection. The original JIM suit had eight annular oil-supported universal joints, one in each shoulder and lower arm, and one at each hip and knee. 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, although actual survival for this time would have been unlikely due to thermal transfer through the magnesium body. As technology improved and operational knowledge grew, Oceaneering upgraded their fleet of JIMs. The magnesium construction was replaced with glass-reinforced plastic
Glass-reinforced plastic
Fiberglass , is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It is also known as GFK ....

 (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 one that was taken from Wasp, this allowed the operator a much-improved field of vision. Trials were also carried out by the Ministry of Defence
Ministry of Defence (United Kingdom)
The Ministry of Defence is the United Kingdom government department responsible for implementation of government defence policy and is the headquarters of the British Armed Forces....

 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 1,000 ft (300 m). 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 6 ft 3 in (1 m 90 cm) 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
Glass-reinforced plastic
Fiberglass , is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It is also known as GFK ....

 (GRP) and was depth-rated for around 2,000 ft (600 m). Two were constructed for Oceaneering, as well as an experimental US Navy version, modified with a torso made of carbon fibre reinforced plastic that would prove unsuccessful. The prototype failed at approximately 1,000 ft (300 m) when tested to destruction.

External links

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