Admiralty Gyro-Compass is made up of six parts marked NAV0487.1-6.
Master compass-Consists of a rotor enclosed in an aluminium alloy case which is mounted in a vertical ring by means of horizontal bearings. The vertical ring is supported by a wire suspension in the phantom ring. Compensator weights are secured to the vertical ring. Mercury boxes, suspended from the phantom by pivots and bearings, apply gravitational force to the gyro element. A spider is held in fixed relation to the fore-and-aft line of the ship, and carries the luber ring, azimuth motor and speed and course corrector mechanism. The spider is gimballed in the binacle ring which is itself supported by anti-vibration and anti-shock mounting.
Control Panel: height 42" (106.7cm), width 28" (71.1cm) and contains switchgear and fuses to control electrical supplies to various components in the installation.
Valve Amplifier: 6.5 x 6.5 12" (16.5 x 16.5 x 30.5cm)
Ampliflier Panel: Patt.987 14.5 x 8.25 x 26.5" ( 36.9 x 21 x 67.3cm) Unit contains a Main Transformer supplying the various high-tension, bias and heater circuits, moving-coil Ammeter, sensitivity control, resistors, rectifiers and connectors. A hinged inspection door is fitted to the front.
Proteus anti-shock mounting: height 6" Provided for attaching master compass to ship's structure. The compression springs are designed to withstand shock of up to one foot in amplitude.
Alarm bell: Patt 3227A Operates as a warning in event of electrical or mechanical failure.