Mark 27 Mod 4 torpedo

The Mark 27 torpedo was the first of the United States Navy 19-inch (48-cm) submarine-launched torpedoes. This electrically-propelled torpedo was 125 inches (3.175 m) long and weighed 1174 pounds (534 kg). The torpedo employed a passive acoustic guidance system and was intended for both submarine and surface targets. Nicknamed "Cutie" by submarine crews, the Mark 27 entered service in 1943 as a defensive weapon. The torpedo was classified as obsolete in the 1960s.
The Mark 27 was essentially a Mark 24 mine which had been modified for submarine launching in a 21-inch (53 cm) submerged torpedo tube by the addition of 1" (25 mm) wooden guide studs mounted on the torpedo's outer shell.