Because of the increase in size and complexity of the underwater 

 operations at SCI, a larger (than the YFU-53) primary range operation 

 ship was needed. The "Elk River" (IX-501), having been recently con- 

 verted from a LSMR, is capable of supporting all the test operations pre- 

 viously assigned to the YFU-53 in addition to some specific DSSP 

 requirements: 



1. Deep (Saturation) Diving for SEA LAB and LOSS 



2. Deep Submergence Rescue Vehicle (DSRV) test and evaluation 



3. Deep Submergence Search Vehicle (DSSV) test and evaluation 



4. LOSS test and evaluation 



5. Component testing for above systems 



6. Deep tethered operations 



The "Elk River" (Fig, 3) is 225 ft long, 50 ft across the beam, and dis- 

 places 1,100 tons. It cruises at 7 knots and has a maximum speed of 11 

 knots. Maximtmi for range and endurance are 3,000 miles and 20 days, 

 respectively. The crew complement is 45 (25 Navy and 20 civilian). 

 Instrumentation and facilities will be comprehensive. including items such 

 as tape recorders, vuiderwater television and still cameras, and dark- 

 room and maintenance facilities. Moreover, it has a 55- by 19-ft center- 

 well with sliding bottom-closure doors. The diving support compart- 

 ments are equipped with the Mk n deep diving system, including two large, 

 4-man,deck decompression chambers (DDC), two 4-man personnel trans- 

 port capsules (PTC), mixed gas stowage, diver's ready room, a station 

 for shallow diving, and auxiliary equipment. A gantry crane is available 

 for handling the PTC's. There is main deck space for four 8- by 35-ft 

 instrumentation and control vans. There is lift equipment capable of 

 hoisting the DSRV and DSSV over the stern or through the centerwell. A 

 fully equipped frame may be lowered through the centerwell for deep 

 search and recovery and component testing. Instrumentation cabling for 

 depths to 6,000 ft and two traction winches with 20,000 ft capabilities are 

 available. A dynamic positioning system is installed on the ship. The 

 ship has a capability for a 5-point moor in depths to 2,000 ft with remote 

 controlled mooring winches. And, finally, it has its own navigation and 

 commimications systems and maintenance facilities such as an electric 

 shop, diver's shop, and work shop. 



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