SUBMARINE MAIN BALLAST TANKS - THEORY AND METHODS FOR REFINED STRUCTURAL DESIGN

Included is a discussion of the nature and history underlying the evolution of submarine ballast tanks, with reference to the Submarine Safety Program stemming from the loss of USS THRESHER. Theory and methods are developed for predicting the pressures applied to a ballast tank, and for the behavior of the tank structure under these pressures. Considered are variables of ballast tank and blow system configuration, initial transient loading and quasi-static pressures. Equations are developed to relate these variables and to determine the level of stress in any part of the tank structure, with theoretical development appended. General applications of these equations to analysis of a ballast tank are presented, with simplified curves and tables appended, and applicability to strutted sandwich shells other than ballast tanks indicated. Finally a complementary test program, established to confirm these equations and including large scale structural models and instrumented structural recovery trials, is briefly described.