[PSUBS-MAILIST] Pisces III rescue

[vbra676539 at aol.com]

The aft sphere has a hatch on top and the outer shell segment was left off for the dive. During recovery operations, the tow line got wrapped around the hatch dogs, and ripped the hatch open. Drop weight and tanks were useless as the buoyancy on that aft sphere grosses at 2-tons (60" sphere). According to Roger Chapman, they had less than 15 MINUTES of life support left when they got out.
Vance



-----Original Message-----
From: jimtoddpsub <jimtoddpsub at aol.com>
To: personal_submersibles <personal_submersibles at psubs.org>
Sent: Tue, Jan 28, 2014 10:56 pm
Subject: [PSUBS-MAILIST] Pisces III rescue


Vance,
Pretty hairy situation.  Apparently they were 76 hours into their 72-hour life support capacity when the rescue was completed.  Do you know how the tank was inadvertently flooded, why they couldn't blow the tank, or why they couldn't release a drop weight to ascend?  Below is the story per Wikipedia:
 
1973 Pisces III rescue
Pisces III was used to lay transatlantic telephone cable on the sea bottom off Ireland in 1973. When a buoyancy tank was inadvertently flooded, it sank to the bottom of the ocean with its two-man crew, Britons Roger Mallinson and Roger Chapman, stranded at a depth of 1,575 feet (480 m) and 72 hours of available life support, which they were able to extend to 76 hours by careful conservation.[2][3][4] Initial rescue efforts by Pisces III sister submersibles were unsuccessful. Through an international effort of the United States, Canada, and Great Britain, the U.S. Navy Cable-controlled Undersea Recovery Vehicle (CURV-III) was deployed within 24 hours 6,000 miles from its home base. Deployment of CURV-III from CCGS John Cabot was hampered by heavy sea conditions. Rapid repairs were made when CURV-III’s gyroscope failed and electronics shorted-out after green water came aboard the Cabot. Assisted by the submersibles Pisces II and Pisces V, CURV-III was able to attach lines to the Pisces III hatch. The Cabot raised CURV-III at 60 to 100 feet (18 to 30 m) per minute until their lines entangled. The lines were cut, CURV-III was abandoned, and Pisces III was floated to 60 feet (18 m) where scuba divers were able to attach lines that were used to lift Pisces III the rest of the way to the surface. CURV-III performed the deepest underwater rescue in history when Pisces III’s two-man crew was rescued after 76 hours with just 12 minutes[5] of air remaining.

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