10 76-242/05 



pre-programmed computer system. High 

 energy density power systems and redundant 

 and emergency modes of operation are 

 required to provide reliable, long endurance 

 operation and safe retrieval of the free 

 swimming robot after mission completion 

 or early termination. 



ATMOSPHERIC DIVING SUIT (ADS) 



A submersible with arms and legs might be 

 an appropriate description for a diving 

 suit called ADS» or originally JIH developed 

 for DHB Construction Ltd., U.S., Figure 10. 

 It allows a man to work effectively at 

 atmospheric pressure in water depths 

 ranging to 1,300 feet. It carries its own 

 self-contained life support system and 

 does not require an umbilical coupling. 

 The advantages of the suit are that the 

 divers do not require decompression and 

 the units require relatively little auxil- 

 iary equipment and deck space. On deck, 

 the unit weighs 1,000 lbs. and remains 

 in place while the diver enters the suit 

 and the head section is attached. A small 

 crane is needed to launch the diver and 

 he can fimction with or without a tether. 

 Also, there are no communication problems 

 like those experienced with helium gas 

 for deep diving. The author believes that 

 as the design evolves and improves, there 

 is much potential for a system of this 

 type, especially as divers advance to 

 deeper depths. 



VEHICLE OPERATION AND SAFETY 



Operation and Handling 



Effective, safe operations are the prime 

 objectives of any vehicle operator. One 

 of the major considerations in this area 

 is vehicle handling in launch and retrieval. 

 Therefore, the vehicle operator is con- 

 cerned with having a compatible, integrated 

 system which includes the vehicle, handling 

 system, and support ship. This is impor- 

 tant if a high annual utilization rate is 

 desired, including operation in rough seas 

 and occasionally poor weather conditions. 



In the U.S. 5 the leading vehicle operator 

 is the U.S. Navy's Submarine Development 

 Group One, San Diego. In commercial work, 

 the most active operators are General 

 Oceanographies, Inc., San Diego; and 



International Underwater Contractors, Inc., 

 New York. In scientific work, the most 

 active are the Woods Hole Oceanographic 

 Institution's ALVIN operations (see Table 

 4), and the Harbor Branch Foundation. 



Outside of the U.S., the most active vehicle 

 operators are Vickers Oceanics, Ltd.; 

 Barrow-in-Furness, England; InterSub, 



Marseille, France; COMEX, Marseille, France, 

 and HYCO Subsea Ltd., Vancouver, Canada. A 

 sampling of the extent of their operational 

 activity is given in Table 5. 



The greatest concentration of vehicle 

 activity is in the North Sea where there are 

 about 15 in operation. The world's most 

 active commercial operator, Vickers Oceanics, 

 Ltd. , has gained much operational experience 

 in the North Sea, and is mainly involved in 

 cable burial and pipeline survey. Figure 11 

 illustrates a PISCES submersible being 

 deployed via their proven method of launch 

 and retrieval. 



They are capable of vehicle launch and 

 retrieval up to sea state 6. The handling 

 system consists of an "A" frame with a sheave 

 for the lifting line extending over the 

 stem of the support ship, and a smaller 

 inverted "A" frame hanging down from the 

 main frame to prevent athwartship motion 

 when the vehicle is hoisted. A hydraulic 

 arm attaches to the bow of the vehicle to 

 prevent fore-aft swinging motion. An 

 important feature of this system is a small, 

 high speed motor which can overrun the main 

 lifting motors whenever the tension in the 

 line goes to some preselected low value . 

 The retrieval procedure follows: The diver 

 attaches the shackle and line; the vehicle 

 is towed toward the ship; the ship begins 

 lifting the vehicle at about the time the 

 wave starts to lift the vehicle; as the wave 

 lifts the vehicle the tension in the line 

 drops; the high speed motor reels in the line 

 at high speed, up to 600 feet per minute if 

 necessary, to maintain the minimum tension 

 on the line; and, as the wave passes and the 

 tension increases, the main winch continues 

 at its normal hoisting speed. This effec- 

 tive approach uses the sea-induced motion 

 rather than trying to cope with it, gradu- 

 ally transferring the lifting action from 

 sea-dominant motion to ship-dominant 

 motion. ^^^ 



