USS Requin (SS-481)

Moored along Pittsburgh’s Three Rivers Heritage Trail, USS Requin (SS-481) presents a late–World War II Tench-class submarine preserved far from salt water, yet still very much a product of the Pacific war and early Cold War. Laid down in 1944 and commissioned in April 1945, Requin was completed with unusually heavy deck armament, including an extra 5-inch gun and rocket launchers intended for the planned invasions of Japan—hardware that underlines how aggressively U.S. submarine design was trending at the war’s end. The sudden peace diverted her from combat to training duty and then to experimental roles, and her subsequent conversion into a radar picket submarine illustrates the Navy’s rapid adaptation of existing hulls to the new threat of long-range aircraft and, later, guided weapons. As a museum ship at the Carnegie Science Center since 1990, Requin offers an intact steel volume where enthusiasts can study the cramped ergonomics of a fleet boat, the complexities of mid-century electronics and sensors, and the layered modifications that trace the shift from World War II patrol submarine to early Cold War surveillance platform.