BROMINE PROM SEA WATER STEWART 163 



In constructing the intake walls, 50-foot lengths of interlocking 

 sheet steel piling were used. These were driven to a depth of about 

 42 feet below mean low-tide level. The parallel rows of piling in 

 each Avail were joined together at every tenth member by a partition 

 of similar piles at right angles to the direction of the wall. Con- 

 sequently, when completed, each wall of the intake consisted of a 

 series of interlocked cells 21 feet long and 15 feet wide. These were 

 built, one at a time, beginning at the shore end and were filled with 

 sand that was dug from the channel between them. 



Altogether the intake (pi. 1, fig. 2) is about 200 feet long. 

 It extends approximately 30 feet out into the ocean at low tide and 

 about the same distance onto the kind at high tide. The channel 

 between the walls is 15 feet wide and the depth is 9 feet below mean 

 low-tide level. 



The sea water flows through the intake into a settling basin which 

 is 112 feet long, 76 feet wide, and 12 feet deep. The walls in this 

 case were formed from a single row of 40-foot steel piles. These 

 were left with about 14 feet exposed above mean low-tide level and 

 are about level with the surrounding ground. 



The walls of the settling basin had to be supported from the 

 outside in order to keep them from collapsing toward the inside. 

 This was accomplished by bolting 24-inch I-beams to every eighth 

 piece of piling and extending 2.5-inch steel rods about 30 feet out 

 from each I-beam to anchor into timber piling which served as 

 " dead men " to absorb the thrust of the dirt against the piling wall. 



In putting down the steel piles, considerable difficulty was ex- 

 perienced in driving the first few members. When these were in 

 place, it was found expedient to use water jets to aid in sinking 

 the subsequent units. A O.T5-inch nozzle was carried down on each 

 side of the piles, and, by forcing the water through the nozzles at 

 100 pounds per square inch pressure, it was possible to drive them a 

 considerable distance merely by raising and dropping them. When 

 the power required to raise a pile became too great for the derrick, 

 the jetting was continued and a hammer applied to the top of the 

 pile until the latter was driven to the desired depth. In order to 

 keep the piles of the intake walls in perfect alignment so that there 

 would be no difficulty in tying-in the cross partitions, a frame was 

 constructed which was suspended in the air and which kept the piles 

 perfectly straight in their desired location. 



Four concrete compartments were built along the end of the set- 

 tling basin opposite the intake. At the present time three of these 

 are closed off with plank bulkheads to keep out floating debris. The 

 fourth compartment has installed at its entrance a 120-inch Link- 



111666—35 12 



