Piston Design Improvement Through Research Investigation

Research and development studies leading to the design of an improved piston for a submarine diesel engine are described. The four phases of the studies are (1) radioactive piston ring wear investigations, which show that this wear increased sharply at the higher engine power outputs; (2) fusible alloy plug temperature measurements; (3) piston thermocouple tests, which led to the conclusion that only by modifying the internal construction of the piston could significant improvement in piston temperatures be made; and (4) redesign of piston. The new piston has raised the reliability of the engine from unsatisfactory to satisfactory, and will now be applied to the engines in the fleet.