"The Swedish FFV Ordnance TP 617 21-inch (533 mm) torpedo is an export version of the Swedish Navy's Type 613 long-range torpedo. Combining wire guidance and acoustic homing it weighs 4,078 lb (1,850 kg) and is 22 feet eleven and a half inches in length (7 m) in length. Designed for use against surface targets by surface ships and submarines, it can also be launched from shore-based submerged torpedo tubes by coastal defence units and has a thermal propulsion system, which uses hydrogen peroxide alcohol and water as propellants. The TP 617 system is designed around a programmable digital computer, which controls the homing system, communications between the torpedo and launch vessel and the torpedo navigation system. The use of wire guidance enables the launch vessel to transmit orders to the torpedo controlling its speed, depth, course and target data, while the torpedo is able to report its position, speed, course and depth, homing system parameters and target noise. Should communications be disrupted the computer automatically calculates the target's expected position and guides the torpedo to the predicted point.

The TP 43XO is intended for use by surface ships, submarines and helicopters against surface ships or submarine targets. Designed around a multi-processor computer system, it features a homing system optimised for use against very quiet submarines in shallow water and combines wire guidance with passive acoustic homing to give a high hit probability, even at long ranges. Speed, depth, course and target data commands can all be transmitted via the guidance wire, while the torpedo reports its position, speed, course, depth, homing system parameters and target noise all of which are stored in a computer.

Good descriptions of the Krupp MaK mine-laying system and the Whitehead A 184 submarine system are also provided. Accession No.1071."