Figure 4-16.--0perating procedures for the Sperry Mk 23 Mod 0 gyrocompass.

B-51 or B-52 alarm panel is used in place of the

MK 23 MOD 0 GYROCOMPASS SYSTEM

annunciator.

The Mk 23 Mod 0 gyrocompass system (fig. 4-15)

consists of the master unit, control cabinet, speed unit,

Alarm Bell

alarm control unit, a compass failure annunciator, and

an alarm belt.

The alarm bell is used with the annunciator to

provide an audible indication of problems within the

Master Unit

gyrocompass system.

The master unit consists of a shock-mounted,

OPERATING THE MK 23 MOD 0

oil-filled binnacle and the gyrocompass element. The

GYROCOMPASS

master unit is designed for deck mounting and weighs

approximately 100 pounds. The compass element is the

Instructions for starting and stopping (securing) the

principle unit of the compass system and is gimballed

compass under normal conditions are on an instruction

in the binnacle to allow 45 of freedom about the pitch

plate (fig. 4-16). This plate is located on the front of the

and roll axes. Drain plugs are located in the lower bowl

control cabinet. There are two modes of operation,

for draining the oil.

normal and directional gyro (DG). The normal mode of

operation is used for latitudes up to 75. The DG mode

Control Cabinet

of operation is used for latitudes above 75. Normally,

the compass should be started at least 2 hours before it

The control cabinet contains all the equipment

is needed for service. For additional information on

required for operating and indicating the condition of

starting the compass, refer to the manufacturer's

the master compass except the visual alarm indicator

technical manual.

and the alarm bell. The control cabinet houses the

If it becomes necessary to stop the compass in a

control panel, control amplifier, follow-up amplifier,

heavy sea for any reason other than failure of the

and power supply.

follow-up system, the following procedure should be

used:

Speed Unit

The speed unit contains the necessary components

to produce an electrical signal proportional to ship's

speed. Speed information is received from the ship's

underwater log equipment or is set in manually by the

ship's dummy log system. The speed range of the unit

is 0 to 40 knots.

Alarm Control Unit

The alarm control unit contains the necessary relays

and components to actuate the lamp on the visual alarm

indicator or the bell alarm when certain portions of the

system become inoperative.

Compass Failure Annunciator

The compass failure annunciator is a visual alarm

indicator. It provides a visual indication of problems

within the gyrocompass system. Under normal

conditions, the lamp on the indicator is lighted

continuously. When a failure occurs within the system,

Figure 4-16.--0perating procedures for the Sperry Mk 23

the lamp flashes or goes out. A test push button is

Mod 0 gyrocompass.

provided on the annunciator. In some installations a type

4-11