Density as a Cost-Driver in Naval Submarine Design and Procurement

Abstract

This thesis examines density reduction as an alternative to weight or size reduction when decision-makers seek options for lower-cost submarine designs. The parameter density measures how tightly systems and equipment are placed within a hull structure. To address design characteristics unique to submarines, this research mainly focuses on submarine design and procurement although the general concepts are applicable to surface ship designs and may be applied more broadly. Based on an examination of density as it relates to cost, this research indicates that (1) the use of weight-reduction policies as a means to reduce cost have often generated the opposite effect; (2) increased cost, schedule and performance risk and an improper mix of design capability and flexibility are the inevitable outcomes of unnecessarily dense designs; and (3) Arc-permeability and Internal Density, measures developed for this research, are sufficient approximations of how tightly systems and equipment are placed within a compartment. Indeed, they may reveal how density represents a significant and previously underemphasized, if not unexplained, driver of historic submarine cost-growth in excess of inflation.