Chapter 15 

 HANDLING CHARACTERISTICS OF SEALAB II 



T. N. Blockwick 

 Boston Naval Shipyard 

 Boston, Massachusetts 



and 

 E. P. Carpenter 

 Naval Ordnaupe Test Station 

 Pasadena, California 



INTRODUCTION 



During construction of Sealab II, eight lifting padeyes were provided. Four of these eight 

 were used whenever Sealab was moved by lifting. Cranes capable of lifting the 200-ton habitat 

 completely out of the water were available in San Francisco and Long Beach. For towing, a 

 closed chock was provided on both the bow and stern. 



The primary restriction imposed on all handling operations was that at no time could the 

 habitat be allowed to come in contact with any dock or floating vessel. This restriction was 

 imposed bacause of the vulnerability of its many exposed fittings, valves, and external gas- 

 storage bottles. 



HANDLING OPERATIONS 



Sealab n was transported from the construction site. Hunter's Point Division, San Fran- 

 cisco Bay Naval Shipyard, to Long Beach Naval Shipyard by barge towed by USNS Gear. At 

 Long Beach, the habitat was placed in the water and towed to the site near La JoUa by USNS 

 Gear. This tow was an event with many unknowns, because the hull of Sealab was not designed 

 for towing. Only the conning tower and 1 ft 8 in. of the main cylinder were above the surface. 

 Most of Sealab was under water. Most of the stores and equipment were loaded at Long Beach. 

 It was planned that only last-minute items would be loaded at the site. 



The most important procedures for preparing Sealab for surface towing was putting on in- 

 ternal and external port covers, placing internal strongbacks on the main access hatch, and the 

 emergency escape hatch. All hatches were closed, and Sealab was pressurized to 20 psi gage. 

 A light alarm was rigged to indicate loss of pressure. If the pressure dropped to 16 psi, the 

 light would be actuated. 



The tow was rigged from one of the forward lifting pads through the bow bull-nose chock. 

 Starting from the lifting pad, the tow was arranged, as follows: pelican hook, 1-1/2-in. chain 

 through bull nose, about 150 ft of 1-5/8-in. wire that was attached to the main 2-in. towing wire 

 of the GEAR (ARS-34). 



The distance from Long Beach to the Sealab 11 site at La JoUa was 80 naut mi, and 36 hours 

 was allowed for transit. This time would give an average speed of slightly more than two knots. 

 However, Sealab towed better than anticipated, and it arrived at the site early. The scope of 

 wire used by the Gear (ARS-34) was only from 100 to 300 ft. The normal minimum of 1200 ft 

 could not be used, since the weight of the 2-in. tow wire could probably cause the Sealab to 

 plunge. After arrival of Sealab at the site, it was moored to the No. 2 mooring spud until it was 

 ready for lowering. 



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