Fig, 6 10 HAKUYO's mechanciaJ weight trim system, 



surface to DEEP DIVERTS maximum operat- 

 ing depth. The system consists of an electric 

 motor, pump, selector valves and fore and aft 

 tanks. It is designed to pump water to or 



from the sea as well as transfer water fore 

 and aft. 



The trim tank in the pilot's compartment is 

 split into six sections. The diver's compart- 

 ment trim tank is split into two sections. 

 Under normal submarine operations both 

 fore and aft tanks are used to maintain trim. 

 During lock-out dives the aft trim tank pro- 

 vides negative buoyancy to partially compen- 

 sate for the weight of the departing divers. 



The trim tanks located in the diver's com- 

 partment can be flooded through the com- 

 partment vent valve or blown dry in 1 min- 

 ute through the same valve by increasing 

 compartment pressure 5 psi over ambient. 



The trim pump is a positive displacement 

 piston type capable of delivering 4 gallons 



OIL 

 PUMP 



4-WAY 



SOLENOID 



VALVE 



AFT TANK 



SOLENOID 

 VALVE 



OIL FILL & 

 BLEED 



OIL 

 RESERVOIR 



FILTER 



RELIEF 

 VALVE, 200 psI 



SOLENOID 

 VALVE 



EXPLOSIVE 

 DUMP VALVE 



EXPLOSIVE 

 DUMP VALVE 



pMERCURY FILL 



y'>_ 



FORWARD 

 TANKS 



EXPLOSIVE 

 DUMP VALVE 



MERCURY DRAIN 

 OR FILL 



EXPLOSIVE 

 DUMP VALVE 



Fig. 6,1 1 Mercury trim system of ALVIN, [From Ref. (5) 



305 



