If the mixture is too thin, the second compartment, or water compart- 

 ment, is brought into use. This compartment has a bottom which is 9.32 

 feet above the base of the surge well. It is divided into two sections, 

 one serving each side of the surge pit and each having three flap-type 

 water gates. When the height of the water in the pit reaches the water 

 flap gates, they can be opened on the side of the pit where the water has 

 accumulated. The water then runs down into the base of the water section 

 and forces the flap gate to the discharge section open, thus draining the 

 excess water into compartment No, 3, and 36-inch sea 'line. This waste 

 water is stopped from entering the other side of the water compartment by 

 the flap gate in that section being held closed by the pressure exerted 

 against the flap gate from water entering the discharge compartment. 



The third section of the well is of the same dimension as the second 

 section, and is only for discharging extra unused water to the sea. Two 

 flap gates are located in the dividing wall between the water section and 

 the waste section, and open out into the waste section. Each of the six 

 gates are activated by hydraulic rams, one for each gate. The flap gates 

 are operated by drum-type winches. The figure showing details of the 

 surge well, sand eductor and sluice pipe gives the actual dimensions of 

 the unit being used at the Hyperion project; however, complete design 

 details are not available. 



To start the sand on its journey, a Hendy hydraulic giant is used. 

 The giant is set from 75 to 250 feet away from the material to be moved. 

 The giant is first set as close to the sand deposits to be moved as 

 possible, and left there until all the material within the range of the 

 giant has been removed. In moving sand, high-nozzle velocity is not 

 needed, therefore it is only a matter of getting the water the required 

 distance to the sand deposit. In operations at the Hyperion project, a 

 No. 4 giant with a 5-inch nozzle is used mainly. This develops a head of 

 from about 100 to 250 feet, delivering from 590 to 1,000 cubic feet of 

 water per minute to the area of operation. At times, it has been more 

 adaptable to use two hydraulic giants at a point of operation. At such 

 times, the size of each giant nozzle is reduced so that the flow of water 

 will be equal to that used by the 5-inch nozzle. The reason for this is 

 the design of the eductor system — one eductor will handle only the water 

 from one 5-inch nozzle. Each giant is mounted on a skid to make it easy 

 to move in sandy areas. 



The eductor is located at the base of the slope in a basin formed by 

 pushing up a barricade of sand about three sides of it, thus letting the 

 water from the giant mixed with the sand flow downgrade and into the basin 

 in which the eductor is located. The slope to the eductor must be great 

 enough so that the velocity of the material will create enough turbulence 

 to hold the sand in suspension. The eductor consists of a square box, 

 tapered towards the base, with an open top and partially open sides. The 

 side sections of the box are made of 0.5-inch plate; the end sections are 

 made of 0.875-inch plate for rigidity. Suspended material flows down into 

 this box and into a venturi pipe connected to the box. A high-pressure 

 line enters into the opposite side of the box, approximately 12 inches 



