figurations and operational capabilities, se- 

 lection of a launch/retrieval system is on an 

 individual basis. Some vehicles are so large 

 and heavy that it is impractical to consider 

 lifting them out of the water after each dive; 

 others, although smaller, are sufficiently 

 large so that the only feasible method is to 

 employ a cradle as with DEEP QUEST or 

 ALVIN. With the smaller vehicles a single 

 point attachment can be used, but protrud- 

 ing instruments or controls may require 

 some vehicles to lay off several feet from the 

 support platform, while others can come 

 quite close. In some submersibles the opera- 

 tor can work in concert with the support 

 platform's Master to effect attachment and 

 retrieval; in others, the operator can do no 

 more than surface and wait for the support 

 crew to retrieve his vehicle. 



Further constraints and considerations in 

 the choice of launch/retrieval systems arise 

 from the owner's or user's method of opera- 

 tion. For example, if the user owns the sub- 

 mersible's support craft, then the launch/ 

 retrieval apparatus can be permanently in- 

 stalled. If one uses a different platform for 

 different operations, then the launch/re- 

 trieval system must be air or truck trans- 

 portable, easily installed and require little, 

 or nothing, in the way of shipboard modifica- 

 tions. Such vehicle characteristics and opera- 

 tional procedures preclude an across-the- 

 board solution to launch/retrieval. 



Possibly the greatest problems are derived 

 from the fact that the launch/retrieval sys- 

 tem, like the support platform, has not been 

 considered until after the submersible is de- 

 signed or constructed. In Doerschuk et al. (5) 

 several systems which showed promise had 



to be abandoned because the procedure 

 might damage external instruments or com- 

 ponents on the DDS-1 by bringing its sides 

 into contact with a part of the retrieval 

 system. If the DDS-2 had been designed with 

 the launch/retrieval system in mind, such 

 protruberances might have been avoided or 

 protected in such a way as not to interfere 

 with the retrieving systems. But the real-life 

 situation is generally the opposite and one 

 must devise a system that does not jeopard- 

 ize the existing vehicle. 



Usry's report summarizes parameters 

 which he evolved in seeking a solution to 

 DEEPSTAR's handling system; these are 

 presented in Table 12.3. It should be noted 

 that these parameters reflect a system that 

 will be used on different platforms and in the 

 open sea. A list of system elements (Table 

 12.4) represents factors concerning the vehi- 

 cle, the platform, personnel and safety which 

 must be considered in relation to the launch/ 

 retrieval system; this table was also taken, 

 in part, from Usry's report and is included to 

 show the many design and operational as- 

 pects one must satisfy. 



The major adversary to any launch/re- 

 trieval system is the state of the sea. Mr. F. 

 Willet of Westinghouse has made the follow- 

 ing calculations which illustrate the prob- 

 lem. Presume an 8-foot-high wave of 5.4- 

 second period and 102-foot length. This short 

 wavelength will move the stern of the vessel 

 and the submersible in relation to each 

 other. The stern will plunge as the submers- 

 ible is on the crest and heave as the sub- 

 mersible is in the trough. With their cycle of 

 motion about 90 degrees out of phase and 

 assuming an 8-foot submersible vertical mo- 



TABLE 12.3 SELECTION PARAMETERS FOR HANDLING CONCEPTS 



-transportable by air or truck 

 -maximum safety and reliability 

 -easy installation on variety of 



ships and platforms 

 -back-up provisions 

 -smooth, positive control 

 -rapid hoist from water 

 -operate in variety of sea states 



reducing relative motion effects 

 -operated without extensive training 



-accommodate variety of vehicles 

 -simple design, standard parts 

 -reasonable cost 



-no additional personnel required 

 -no positive action required 



of vehicle being recovered 

 -not require swimmers for critical 



attachments or maneuvers 

 -utilize minimum deck space 



—require no modification to 



mounting platform or ship 

 —minimum maintenance and equipment 

 —no inhibiting effect on vehicle design 

 —reduce need for critical skills on 



part of ship operator 

 —minimize handling effects on vehicle 

 —useful for other equipment 



handling 

 —power source requirements 



595 



