ALVIN, a bow line assists the submersible in 

 and out of the well. Rubber fenders line each 

 side of the stern well for additional protec- 

 tion, and a net spans the forward end of the 

 well to protect the bow against collision with 

 the forward bulkhead. During launch, 

 TRANSQUEST maintains slight headway 

 and DEEP QUEST is essentially paid out of 

 the well; during retrieval TRANSQUEST pro- 

 ceeds at 1 to 2 knots into the sea and the bow 

 line is used to haul the submersible into the 

 well. With assistance from the line handlers 

 and the submersible's pilots, it is eased into a 

 position where the cradle (6.5 ft below the 

 keel) can begin to lift. TRANSQUEST is de- 

 signed with four ballast tanks, port and star- 

 board, which permit draft changes from 6.5 

 to 10 feet to facilitate launch/retrieval. 



Submarine (Fig. 12.13): Specially modified 

 nuclear submarines can be used for sub- 

 merged launch and recovery of the U.S. 

 Navy's DSRVs. The DSRV is placed on the 

 submarine's after rescue hatch at the pier 

 and can be transported at a submerged 

 speed of 15 knots. At the launch site it is 

 unlocked from within the mother submarine 

 to conduct its mission. A transponder on the 

 mother submarine is used by the DSRV to 

 locate it for docking. Reflective paint marks 

 obstructions on the submarine and high- 

 lights mating areas and guide lights on indi- 

 vidual pylons. External television on the 

 DSRV is used to monitor final approach and 

 tie down. With the DSRV secured to the after 

 hatch, ballast and life support replenish- 

 ment, battery charging and other servicing 

 and minor repairs can be conducted under- 

 water or on the surface. This system is not 

 restricted by sea state. 



Submerged Platform (Fig. 12.13): To avoid 

 the turbulence of the surface, the Naval 

 Undersea Center has constructed and tested 

 a towed, underwater, launch/retrieval plat- 

 form called LARP (Launch and Recovery 

 Platform). LARP is a catamaran structure 

 consisting of two compartmental cylindrical 

 fiberglass hulls cross-connected by four alu- 

 minum pipes; the latter are overlayed by an 

 aluminum grating with appropriate cutouts 

 for controls, etc. Three fiberglass-covered ur- 

 ethane blocks provide buoyancy and stability 

 and house 12 each 200-cubic-foot-capacity 



compressed air bottles which serve to debal- 

 last the hull. Forward on the platform are 

 remote and manual valves for controlling 

 buoyancy. The platform is presently capable 

 of lifting 10 tons and is 35 feet long, 18 feet 

 wide, 7 feet high and weighs 8.5 tons in air. 



During tests LARP was towed with a sub- 

 mersible (MAKAKAI) aboard. Reaching the 

 dive site the tow ship layed to, and four 

 divers flooded the main ballast compart- 

 ments and, subsequently, the variable bal- 

 last tanks. At 60 to 70 feet deep LARP was 

 made to "hover" by control of the variable 

 ballast tanks. The submersible's tie-downs 

 were released by the divers, and the vehicle 

 "flew" off the platform which was then sur- 

 faced. Retrieval involved the reverse proce- 

 dure. Remote control of LARP's ballasting/ 

 deballasting was possible, but remote control 

 of the tie-downs was not. 



A further refinement to LARP (in experi- 

 mental design) is BALARE (Buoyancy Ac- 

 tuated Launch and Retrieval Elevator) in 

 which a similar platform is attached by two 

 pivoting, telescoping arms to the stern of the 

 support ship. The hydraulically-operated 

 arms bring the platform close to the support 

 vessel where maintenance/repair can be ef- 

 fected without the use of divers and where 

 the platform, because it is firmly held, as- 

 sumes the same motion as the support ship. 



Stern-Mounted A-Frame (Fig. 12.13): Vick- 

 ers Oceanics employs this system to launch/ 

 retrieve their PISCES series vehicles from 

 aboard the support ship VICKERS VOY- 

 AGER. Basically the system works as fol- 

 lows: To retrieve, a line is attached by divers 

 to the vehicle's stern which is used to draw it 

 within hook-up range of a 6-inch wire rope 

 attached by divers to a lift padeye aft of the 

 sail. The lift rope is fairleaded through the 

 apex of the frame and the arm or pendant 

 and is wound about a specially-developed 

 compensating winch which always keeps the 

 rope taut. With the submersible drawn up to 

 the pendant, the pendulum effect is slight 

 and the vehicle is drawn stern-first onto the 

 support craft. Rotation of the submersible in 

 the horizontal is checked by steadying lines 

 attached port and starboard. According to 

 Goudge (6) a 12-ton submersible has been 

 recovered in 14-foot seas and larger swells; 



604 



