the only detailed civilian guides for submers- 

 ible construction. Classification by the Bu- 

 reau is instigated by the submersible owner 

 at his request, and all expenses incurred in 

 the process are borne by him. These ex- 

 penses may range from $2,500 for a NEK- 

 TON-type vehicle to over $25,000 for a BEN 

 FRANKLm-type vehicle (M. Letich, ABS, 

 personal communication). 



The American Bureau of Shipping defines 

 a submersible as ". . . any vessel or craft 

 capable of operating under water, submerg- 

 ing, surfacing and remaining afloat under 

 weather conditions not less severe than Sea 

 State 3, without endangering the life and 

 safety of crew and passengers." In their 

 Guide for the Classification of Manned Sub- 

 mersibles (9) they present the requirements 

 and procedures which must be considered in 

 the certification of a submersible by ABS. 



ABS states in the foreword to their guide 

 that their limited commercial experience in 

 submersible operations requires that the 

 guide be considered as an attempt to make 

 various procedures and techniques available 

 to designers until sufficient operating expe- 

 rience is available from which more defini- 

 tive requirements can be formulated. In es- 

 sence, the guide presents the minimum re- 

 quired information for drawings and calcula- 

 tions which must be submitted for classifica- 

 tion. Additionally, a portion of the guide 

 deals with surveys required during and after 

 construction by ABS surveyors. 



Required Drawings 



— Pressure hull and appurtenances 



— Non-pressure hull (superstructure, 

 fairwater, etc.) 



— Tanks not subject to submergence 

 pressure 



— Foundations to equipment 



— Ballast and blow systems 



— Deballasting/jettisoning systems 



— Release devices for external appen- 

 dages 



— Anchor, lifting and handling systems 



— Propeller 



— Propulsion machinery with shafting, 

 bearings and seals 



— Control surfaces 



— Electric wiring and equipment 



— Life support systems 



— Fire fighting systems 



— Intership communication systems 



— Ship-to-shore communications 



Required Calculations 



— Stability (normal and emergency) 



— Buoyancy 



— Equilibrium polygon 



— Minimum freeboard 



— Foundations to vital equipment 



— Tanks subject to submergence pres- 

 sure 



— Pressure hull 



— Life support 



— Lifting and handling attachments 



— Electric load analysis 



— Piping systems vital to crew safety and 

 vehicle survival 



Buoyancy Characteristics 



1) Surface Buoyancy — Through calcula- 

 tions and/or tests demonstrate that the vehi- 

 cle can surface and remain so without jeop- 

 ardizing vehicle safety in normal sea condi- 

 tions (Sea State 3) and with adequate free- 

 board. 



2) Neutral Submerged Buoyancy — Through 

 calculations and/or tests demonstrate the ve- 

 hicle's ability to hover at a fixed depth at 

 even keel at zero speed while submerged and 

 under all loading conditions unless acted 

 upon by an outside force. 



Stability and Trim Characteristics 



The designer must demonstrate through 

 calculations and/or tests that the stability 

 and trim characteristics of the vehicle are 

 adequate for the following Normal condi- 

 tions: 



1) Operating on the surface 



2) Transient 



3) Underwater operation 



The designs must also show by calculation 

 and/or tests that under any possible combi- 

 nation of dropped jettisonable weights the 

 submersible would retain adequate stability; 

 this is referred to as Emergency or Damage 

 Condition. Additionally, the vehicle's ability 

 to survive within certain identified damaged 

 conditions should be verified by calculation 

 and/or testing. 



Ballast System Requirements 



Owing to its extreme importance to safe 



645 



