TABLE 14.4 EMERGENCY CORRECTIVE/ASSISTANCE SYSTEMS (SURFACED) 



Emergency 



Separated from Support Craft 



Instruments 



Radio 



Underwater Telephone 



Flashing Light 



Radio Signal 



Distress Rockets 



Flares 



Anchor 



Breathing Gasses Expired 



components. In this situation the inaccuracy 

 of the depth gage is more than offset by the 

 liberal safety factor. For example, if a vehi- 

 cle's operating depth is 1,000 feet, a safety 

 factor of 1.5 allows 1,500 feet before reaching 

 collapse depth. At 1,000 feet a pressure gage 

 reading within ±50 feet of that depth is well 

 within the vehicle's ability, not only to sur- 

 vive, but to function routinely. 



Automatic Deballasting Devices: 



Two procedures are incorporated on sev- 

 eral submersibles which automatically func- 

 tion to provide positive buoyancy if it pro- 

 ceeds beyond operational depth. One system 

 (DS-4000) automatically drops a weight be- 

 yond 4,400 feet; on STAR III the same proce- 

 dure is available, but only if the high pres- 

 sure air system (used to deballast the main 

 ballast tanks) falls below a critical pressure 

 level (185 psi below ambient pressure). In 

 other vehicles (BEI\ FRANKLIN, SHINKAI, 

 MERMAID nil and the TOURS series) a 

 pressure sensing device activates blowing 

 the main ballast tanks if the vehicle jour- 

 neys below operational depth. The remaining 

 submersibles with automatic deballasting in 

 Table 14.1 drop iron shot when electrical 

 power fails regardless of depth. The TOURS 

 vehicles constitute a special case whereby 



Open Hatch (Sail Allowing) 



Inflatable Trunk Around Hatch 



Inflatable Bags (Increase Freeboard) 



Snorkel 



External Gas Replenishment Connections 



automatic deballasting occurs not only below 

 operating depth, but every 13 minutes at any 

 depth unless the operator takes preventative 

 action. The drawbacks of such systems are: 



1) They are governed by the accuracy of the 

 activating mechanism's sensing device; and 



2) they do not take into consideration all 

 possible operating situations. Let us imagine 

 that DEEPSTAR 4000, for example, is work- 

 ing at its operational depth underneath an 

 overhanging cliff or cable and inadvertently 

 exceeds 4,000 feet. Automatic deballasting 

 might send it up into the very hazard it 

 wished to avoid. The timed deballasting in 

 the TOURS vehicle opens the door for 

 greater susceptibility to overhead hazards 

 and untimely surfacing and detracts from 

 operator efficiency because he must now con- 

 centrate not only on the job at hand, but 

 keep track of time as well. 



Buoys: 



In the early days of submersibles it was 

 considered a safe practice to tie a large buoy 

 on the vehicle with a length of line that 

 would, in addition to facilitating tracking, 

 prohibit the vehicle from exceeding its opera- 

 tional depth. The pitfalls of this practice 

 became evident before the safety line inex- 

 tricably snarled on an obstruction and 



655 



