Submersible Rescue (Ref. 44) 



The submersible DEEP QUEST became 

 entangled in a ^/s-inch polypropylene line 

 attached to a 1,600-pound (wet weight) recov- 

 ery device at a 430-foot depth off San Diego. 

 Not wishing to jettison its expensive equip- 

 ment to surface and with the boat at a 

 precarious trim angle, Lockheed manage- 

 ment called in NEKTON to cut the line. A 

 diver's knife was tied to the smaller vehicle's 

 3-foot-long mechanical manipulator and it 

 cut the line 13 hours after DEEP QUEST 

 became entangled. In a similar but less ur- 

 gent task, the bathyscaph ARCHIMEDE 

 freed the unmanned SP-3000 from a depth 

 of 3,400 meters in 1971 in the Mediterranean 

 (45). SP-3000 was being lowered on a test 

 dive. A weight was attached 17 meters below 

 on a nylon cable to counteract the submers- 

 ible's positive buoyancy. The lowering cable 

 attachment to the vehicle unscrewed and SP- 

 3000 sank to the bottom where it remained 

 "at anchor." No equipment was in existence 

 that could operate at 3,400 meters to cut the 

 cable. Three devices were immediately de- 

 signed and manufactured: A double system 

 of cleavers placed on the fender of AR- 

 CHIMEDE, two rotating shear devices and a 

 mechanical shear with springs. All three sys- 

 tems were fitted on the bathyscaph for its 

 dive. SP-3000 had both an external pinger 

 and transponder. /IRCH/MEDE used the pin- 

 ger to determine the azimuth of SP-3000 

 and advanced to within 1,350 meters of it 

 when its CTFM detected the transponder. 

 The bathyscaph was maneuvered into a posi- 

 tion where the rotating shear was used to 

 cut the cable and allow SP-3000 to surface. 

 Interestingly, from a historical point of view, 

 the first SP-350 hull (then DIVING SAU- 

 CER) was lost 14 years earlier in an identical 

 fashion (46). 



Hardware Inspection 



A number of submersibles have been used 

 to inspect cables, pipelines, offshore struc- 

 tures and a variety of other hardware. Such 

 missions incorporate visual observations, TV 

 video recorders and still and motion picture 

 cameras. The types of instruments vary ac- 

 cording to the submersible. In one mission 

 SHELF DIVER followed a diver while he 

 inspected a pipeline and supplied his breath- 



ing gas mixture from a hose within its lock- 

 out compartment (Fig. 11.22); in another in- 

 stance, the same vehicle inspected 0.6 mile of 

 the inside of a 15-foot-diameter pipe carrying 

 fresh water beneath the French Alps. 



Artifact Mapping (Ref. 47) 



The submersible ASHERAH was used by 

 the University of Pennsylvania to map ster- 

 eophotographically a 4th century Roman 

 shipwreck in 130 feet of water off Bodrum, 

 Turkey. The resultant photomosaic (Fig. 

 11.23) of the 20- x 40-foot area was used to 

 produce a topographic chart with an accu- 

 racy of 1.5 inches in three dimensions. 



To conduct this work the following instru- 

 ments were used: 



2 — 70-mm cameras (Hydro Products PC- 

 750) 



2 — 20-W/sec strobe lights 



Fig 1122 SHELF 0/V£n behind the diver (Perry Sub. Builders) 



571 



