Howell torpedo

The Howell Automobile Torpedo was the first self-propelled torpedo produced in quantity by the United States Navy, which referred to it as the Howell Mark I torpedo. It was conceived by Lieutenant Commander John A. Howell, United States Navy, in 1870, using a 60 kg (130 lb) flywheel spun at a very high speed (10,000 to 12,000 rpm) to store energy and drive propellers.