JIM suit

The petrochemical 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.

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.

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 (500 kg) in air including the diver.

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 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.

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.

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.

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.