The Mountbatten station-keeping system was designed to allow ships to keep station (i.e. to keep their relative position in a convoy) by passing distance corrections to the engine room so that the ship would automatically gain or drop the required distance without the officer of the watch having to steer the ship, thus allowing the officers to devote their attention to manoeuvering and, in combat, fighting.

The instrument works by comparing the revolutions per minute (r.p.m.) of the shaft as ordered with the actual r.p.m. and indicating any difference on the large dial. If the two speeds are the same, the pointers will be at the zero position (vertical). If the ship is out of station, however, the officer of the watch uses the hadwheel on the side to rotate the pointer to indicate that the ship is off station. This automatically transmits the order to the engine room to alter the speed to re-centre the indicator.