The Tigerfish was fitted with both active and passive sonar and could be remotely controlled through a thin wire which connected it to the launching submarine.

This gives the torpedo the time needed to close the range while target course and speed are being updated by the submarine's superior sensors and transmitted 'down-the-wire'.

In addition, the closure of the Torpedo Experimental Establishment, Greenock, Scotland in 1959 and the transfer of its staff to Portland in Dorset disrupted the pace of development.

The propulsion system was changed from an internal combustion engine to an electric motor with a silver zinc battery as the power source.

The torpedo depended in large part on the remote-control system, but the weapon tended to dip during launch, severing the control wire.

A redesigned version, designated the Tigerfish Mod 1, aimed to rectify some of the original model's faults but failed its initial fleet acceptance trials in 1979 despite some improvements.

[6] When HMS Conqueror sank the ARA General Belgrano during the 1982 Falklands War she used the "point and shoot" 21-inch Mark VIII torpedoes rather than her Tigerfish.

The Mark VIII had no homing system but, despite the design being over 50 years old at the time, was far more reliable and carried a greater high-explosive payload.

The Royal Navy's need for a reliable means of dealing with fast, deep-diving, time-urgent targets at long range resulted in a project to arm Tigerfish with a nuclear warhead to offset its poor diving depth and homing performance and to push kill probability close to 90%.

Alternatively, at the initiative of Flag Officer Submarines (FOSM), a nuclear warhead might be fitted to the unguided, shallow-running and short-ranged, but reliable Mark VIII torpedo.

The Marconi Consolidation Programme of the early 1980s finally produced the Mod 2 with reliability improved to 80%, which the Royal Navy accepted as the best that could be achieved with a basic design that was incapable of further development.