The U.S. Navy Racer Development Program

Abstract

The marine gas turbine initially became a predominate force for U.S. Navy surface combatant main propulsion upon selection of the General Electric LM2500 to power the SPRUANCE Class destroyers (DD 963) in 19691. There had been numerous earlier applications of gas turbine engines on hydrofoils, minesweepers, and auxiliary power supply units, all of which contributed to a major surface Navy commitment to gas turbines in 1969. By 1985, approximately 50 percent of the U.S. Navy’s non-nuclear combatant ships will be powered by gas turbines and it is expected that this may approach 100 percent by the year 2000. In 1975, this was recognized as a possibility as was the realization that the U.S. Navy’s fossil fuel supplies could now be disrupted by outside influences. Prior to this time, the U.S. Navy’s surface combatant main propulsion research and development was clearly being driven towards developing a “family” of simple cycle marine gas turbines varying in size from 1,000 to 50,000 hp. High efficiency and energy savings, although considered, were not driving factors in the overall design and development of these engines. Studies were initiated in 1975 to determine if a major improvement could be made in fossil fuel main propulsion plants for surface combatants while retaining the inherent advantages of the marine gas turbine. Twenty-six different candidate configurations were examined in 1975 including simple cycle, recuperated, closed cycle, and combined cycle gas turbine plants. In the final analysis, a Combined Gas and Steam Cycle (COGAS) power plant was chosen for development based on its superior life-cycle cost advantage and the commercial market potential it offered. The General Electric main propulsion LM2500 was chosen as the best candidate gas turbine for efficiency improvement based on its current production schedule, future applications potential, and minimum logistic support impact. Approval to proceed with development was received in July 1977, at which time a technology program was launched to establish a sound baseline for full-scale prototype development.