The Balao class was a design of United States Navy submarine used during World War II, and with 120 boats completed, the largest class of submarines in the United States Navy. An improvement on the earlier Gato class, the boats had slight internal differences. The most significant improvement was the use of thicker, higher yield strength steel in the pressure hull skins and frames, which increased their test depth to 400 feet (120 m). Tang actually achieved a depth of 612 ft (187 m) during a test dive, and exceeded that test depth when taking on water in the forward torpedo room while evading a destroyer.

The Cleveland Diesel Engine Division of General Motors (GM) was a leading research, design and production facility of diesel engines from the 1930s to the 1960s that was based in Cleveland, Ohio. The Cleveland Diesel Engine Division designed several 2 stroke diesel engines for submarines, tugboats, destroyer escorts, Patapsco-class gasoline tankers and other marine applications. Emergency generator sets were also built around the Cleveland Diesel and were installed in many US warships. The division was created in 1938 from the GM-owned Winton Engine Corporation and was folded into the GM Electro-Motive Division in 1962. The engines continue in use today on older tugs.