RESCUE CAPSULE 



VIEWPORT 



Fig. 14.9 Schematic of the Japanese submersible SHINKAI showing location of releasable rescue capsule. 



the entangled object is light enough to be 

 carried to the surface, then the vehicle's 

 normal or emergency deballasting proce- 

 dures may be used. If this is not the case, 

 then the procedures under Loss of Normal 

 Surfacing Ability must be employed, i.e., jet- 

 tison the fouled component, release the pres- 

 sure hull or emergency capsule or egress the 

 vehicle. In addition, if life support endurance 

 is sufficient, assistance from the surface 

 craft or other submersibles is also included 

 in the arsenal of emergency procedures. The 

 first line of defense against entanglement is 

 a smoothly faired vehicle. If there must be 

 items which could snag objects they should 

 be jettisonable. 



Flooding 



Flooding of a submersible may occur in 

 compartments, other than the pressure hull, 

 which are also critical to safety. Critical com- 

 partments are the battery pods, main and 

 variable ballast tanks and motor and other 

 component housings. Detection of flooding is 

 accomplished, for example, by installing self- 

 powered twin electrode systems that set off 

 an alarm when seawater completes the cir- 

 cuit between the electrodes. On the Perry- 

 built submersibles such sensors are located 

 fore and aft in the battery pods and consist 

 of twin electrodes mounted within a polyvi- 



nyl chloride (PVC) tube, with each unit being 

 powered by its own 9-volt battery. When 

 flooding occurs both a visual (light) and an 

 audio alarm are activated to inform the pilot. 

 Flooding within the pressure hull is detected 

 visually by the occupants and, in the small 

 confines of submersibles, does not go unde- 

 tected. Depending on the location, nature 

 and extent of the flooding, the standard pro- 

 cedure is to surface. If flooding of the pres- 

 sure hull is severe, every emergency debal- 

 lasting system available may be used to sur- 

 face and decrease the pressure differential 

 across the leaking area. Several Perry-built 

 boats, to counteract flooding, carry a trim 

 pump within the pressure hull that pumps 

 water out of the hull through an overboard 

 dump valve. 



All leaks are not necessarily emergency 

 situations. BEN FRANKLIN, for example, 

 took water aboard when drifting between 600 

 and 700 feet during its entire 30-day drift in 

 the Gulf Stream. The leak was between the 

 housing of an electrical penetrator and the 

 hull and amounted to no more than an occa- 

 sional drop of seawater. During its deeper 

 (1,500-ft) excursions the increased external 

 pressure squeezed the housing and penetra- 

 tor together and the leak ceased. 



As a flooding control method, SEA 

 RANGER 600 provides for the introduction 



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