Type 91 torpedo - Definition and Overview

The Type 91 was a 17.7 inch diameter torpedo of the Imperial Japanese Navy. Designed primarily to be launched from an aircraft, it was also used by midget submarines.

Seven models were produced in all, with warheads ranging from 331lb (model 1) to 926lb (model 7) and ranges from 1500 to 2000m at 44 knots. The later, heavier models had decreased range, but this was not an operational problem as close launching was necessary for accuracy in any case. Note there were no models 5 or 6, but three different versions of the model 3 differing mainly in their maximum launch speeds.