Figure 4-14.--Effect of weights on the gyroscope.

Figure 4-14.--Effect of weights on the gyroscope.

SPERRY MK 23 GYROCOMPASS

acceleration and deceleration. There are several

SYSTEMS

methods used to do this. The method used depends on

the type of gyrocompass. For further information on the

The Sperry Mk 23 gyrocompass is a small electrical

compass that is used aboard many naval vessels to

method of damping used in the gyrocompasses installed

furnish heading data. On many of the small combatant

on your ship, refer to the applicable manufacturer's

vessels and larger auxiliary vessels, it is used as the

technical manual.

master compass. On some of the larger combatant

vessels, it is used as a backup compass. The compass is

capable of indicating true north accurately in latitudes

GYROCOMPASS SYSTEMS

up to 75N or S. The compass also can be used as a

directional gyro when nearer the poles.

There are a wide variety of gyrocompass systems

Unlike the mechanical gyrocompass, which uses

i n s t a l l e d on Navy ships in the fleet today.

weights that are affected by gravity to cause the desired

G y r o c o m p a s s e s are identified by the mark

period of damping, the Sperry Mk 23 gyrocompass uses

(Mk)modification (Mod) system. The Mk number

a special type of electrolytic bubble level (gravity

designates a major development of a compass. The Mod

reference), which generates a signal proportional to the

tilt of the gyro axle. This signal is then amplified and

number indicates a change to the major development.

applied to an electromagnet which applies torque about

The most common type of gyrocompasses found in the

the vertical and/or horizontal axes to give the compass

fleet today are the electrical gyrocompass systems, such

the desired period and damping. The gyrocompass is

as the Sperry Mk 23, Sperry Mk 27, and the Sperry Mk

compensated for speed error, latitude error, unbalance,

19 Mod 3.

and supply voltage fluctuations. An electronic follow-up

system furnishes accurate transmission of heading data

There are also two new gyrocompass systems

to remote indicators.

currently being installed on Navy ships today. These are

The original Sperry Mk 23 gyrocompass (Mod O)

the Stabilized Gyrocompass Set AN/WSN-2 and the

has had several minor modifications and one major

Inertial Navigation Set AN/WSN-5. Operation of the

modification (Mod C-3). Only the Mk 23 Mod O and

A N / W S N - 5 is classified; therefore, only the

the Mk 23 Mod C-3 will be discussed in this training

manual.

ANAVSN-2 will be discussed in this training manual.

4-9