[1] 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.

Because it had no complicated engine and fuel system, the Howell was much cheaper and easier to build than its main competitor, the Whitehead.

In addition, unlike the Whitehead, the Howell was wakeless, not giving away the position of the firing vessel; its flywheel was, however, very noisy.

When, in an attempt to improve directional stability, Whitehead (using a Ludwig Obry design) adopted the gyroscope in 1895, Howell sued for patent infringement.

A contemporary account of an operational test carried out on a Howell torpedo described its performance, where it "ran along the surface at a very fast but very regular speed for four minutes" and that there was "no horizontal deviation and the run was fully 900 yards".