The critical difference between land and 

 air transport of submersibles lies in the pos- 

 sibility of pressure loss within the aircraft 

 cabin; a loss of this nature may cause bat- 

 tery gassing, expansion of entrapped air in 

 hydraulic systems or, at the extreme, pop- 

 ping of viewports. In some instances, such as 

 leaking of battery acid, the failure may be 

 detrimental to the safety of the aircraft as 

 well as to the integrity of the submersible. A 

 study performed on the DSRV identified the 

 potential critical components on the vehicle 

 with respect to aircraft cabin pressure loss. 

 Because of the DSRV^s sophistication, it is 

 believed this list (Table 12.1) encompasses all 

 components found on any submersible which 

 might constitute an air shipping hazard. 



Sea 



Transportation of a submersible as cargo 

 aboard ship is relatively simple and primar- 

 ily involves tying it down securely and assur- 

 ing that a capability to lift it exists at both 

 the port of embarkation and debarkation. 

 This latter consideration can be a problem 

 with the large (over 25-ton) submersibles. 

 The 142-ton BEN FRANKLIN required two 

 100-ton-capacity cranes (Fig. 12.3) to handle 



Fig. 12.3 The 142-lon BEN FRANKLIN requires two 100-ton (each) capacity cranes 

 to lift It out of the water (NAVOCEANO) 



TABLE 12.1 AIRCRAFT-HAZARDOUS DSRV COMPONENTS AND MATERIALS 



Item 



Failure Mode 



Failure Effect 



Oxygen Bottles 

 Nitrogen Bottles 

 Air Bottles 



Explosion/rupture/jeak 



Fragments and release of O2, No, or air. 



Mercury 



Dump valves open inadvertently 



Contamination of aircraft; release of toxic fumes 

 and cfiemlcal reaction with metals. 



Refrigeration Unit (contains Freon) 



Rupture/leak 



Under combustion heat would release toxic gas 

 (phosgene). 



Explosive cutters 



Inadvertent detonation 



Units jettisoned (pan & tilt, manipulators, etc.) 

 fall free; not considered a hazard. 



Hydraulic fluid 



Rupture of hydraulic line or power unit 



Spillage of fluid. Fire hazard. 



Batteries: 

 Ag-zn 

 Lead-acid 



Rupture of battery case and box. 

 Outgassing due to temperature rise above 

 100°F (becomes severe at 140° F) 



Electrolyte causes corrosion and skin burns. 

 Silicon oil is flammable (flash point 330° F) 

 Release of Hydrogen gas. 



Fire Extinguishers 



Rupture/Leak 



Release of Carbon Dioxide. 



580 



