Johnson Sea Link accident
During a seemingly routine dive off Key West, the submersible Johnson Sea Link was trapped for over 24 hours in the wreckage of the destroyer USS Fred T. Berry, which had been sunk to create an artificial reef.
The aft compartment was designed for lockout diving, allowing two divers to be compressed to the ambient pressure of the ocean and leave the submersible to work underwater.
[6][7] An air conditioning unit was installed on the aft starboard side of the acrylic sphere, creating a blind spot for the pilot.
The objective of the mission was to recover a fish trap from the destroyer USS Fred T. Berry, which had been sunk to create an artificial reef.
Shortly after 9:45 a.m, the Sea Link became entangled on a cable in the Fred T. Berry's wreckage while moving away from the sunken ship, 360 feet (110 m) below the ocean surface.
Menzies took off his shirt, emptied the carbon dioxide absorbent Baralyme from the scrubber canister into it and held it in front of the circulating fans of the air conditioning unit, lowering the CO2 level in the pilot's cabin.
Two hard hat divers from the Tringa attempted to descend to the Sea Link, but had to turn back when their progress was impeded by the hull of the Berry.
A lockout dive by Link and Stover was considered, but they again expressed their desire not to lock out, and Pilot Menzies and the Sea Diver crew agreed.
501922) arrived on the scene carrying an underwater television camera with a maneuverable platform,[2][5] a device from the Naval Ordnance Laboratory in Fort Lauderdale, Florida.
The compartment was force ventilated with a helium-oxygen mixture while remaining pressurized, and hot water was sprayed over it in an attempt to raise its internal temperature.
The investigators concluded that the accident was caused by pilot error, possibly due to distraction, and by the hull shape of the Sea Link.
[2][5] According to the investigators, "The submersible's modular construction of irregular shapes, projections, and appendages provide an excellent configuration for ensnarement by almost any type of obstruction.
Edwin Link spent the following two years designing an unmanned Cabled Observation and Rescue Device (CORD) that could free a trapped submersible.
[4][5][7] The two submersibles remained in operation for many years, examining the wreck of the USS Monitor in 1977 and helping recover the wreckage of the Space Shuttle Challenger after its destruction in 1986,[7] but were retired in 2011.
[18] In 1978, Compass Publications established the National Ocean Industries Association Safety in Seas Award, partly in memory of Link and Stover.
