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.
An animation of the Howell 14.2 inch torpedo from 1896. This torpedo uses a heavy flywheel as its motive power, and for a time was considered an alternative to the Whitehead torpedo.
The flywheel had to be spun up to 10,000 rpm by an external engine (Barker mill) before launching. The Howell had excellent directional stability and left no visible trail of bubbles, but had limited range.
It was phased out of use in 1907. This model uses the drawings from the U.S. Navy’s Manual on the Howell Torpedo 14.2 inch Mark I, 1896.