Three movable Quonset-type cover sections are available 

 to provide protection from the weather for 15-foot sections of the 

 tank during construction or operation. Each of these 4,000-pound 

 galvanized steel cover sections can be used independently or as 

 one continuous length. The three sections protect a total area of 

 about 1,300 square feet including a 6-foot width on each side of the 

 tank. The maximum head room available is 15 feet. 



The wave generating mechanism (Figures 14 and 15) consists of 

 a vertical bulkhead 15 feet wide and 23 feet high mounted on a carriage. 

 The carriage moves back and forth on rails mounted on each wall of 

 the tank. Top rails and dual spring loaded wheels are required to 

 prevent lifting of the carriage from the rails during operation. The 

 back and forth motion is transmitted to the bulkhead and carriage by 

 two arms, 42 feet 9 inches in length connected to two driving discs. 

 Each disc is 19 feet in diameter and weighs 14 tons. The discs are 

 driven through a train of gears by a 510 hp, 2,300-volt synchronous 

 motor running at a constant speed of 1,200 revolutions per minute. 



Three sets of gears in the first reduction and four sets 

 of gears in the second reduction permit variations in the speed of 

 the discs. The alternative gearing will allow generation of wave 

 periods of approximately 1.85, 2.61, 3.12, 3.75, 4.38, 5.31, 5.60, 

 6.31, 7.87, 8.92, 11.33, and 16.01 seconds. The maximum usable 

 wave height is approximately 6 feet. The distance that the bulk- 

 head moves can be varied from 2 to 17^ feet by changing the eccentric 

 setting of the connecting arms on the driving discs. The stroke 

 setting may be varied in 3-inch increments through the range from 2 

 to 8 feet and in 6-inch increments from 8 to 17^ feet. When the 

 connecting arm eccentric setting on the disc is changed, the disc is 

 rebalanced with counterweights. The counterweights required for 

 balancing range from 378 pounds for each disc for the shortest 

 (2-foot) stroke to 3,820 pounds for each disc for the longest (171- 

 foot) stroke. Normally waves are generated by back and forth motion 

 of the vertical bulkhead. However occasionally lower waves are 

 desired. These caji be generated for some of the shorter wave periods 

 (as the smallest eccentric setting possible is 2 feet). Consequently 

 the mechanism has also been adapted to connect to a further bulkhead, 

 hinged to the bottom, which may be installed when desired to give 

 waves with heights about half those available with the vertical 

 bulkhead. 



Supporting Facilities . - (a) A library of foreign and 

 domestic documents on coastal engineering, including a file of 

 approximately 30,000 ground and aerial photographs of coastal areas. 



(b) A photographic laboratory equipped to process 

 black-and-white and color film, and print contact pictures or en- 

 largements of black-and-white negatives. Included in the equipment 

 of the photographic laboratory are: 4 x 5 -inch press cameras, 35-mm 



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