(1) Compasses.
(a) The ship is equipped with magnetic and gyrocompasses. The master gyrocompass is located below decks in the gyro-room. The readings of this compass are transmitted to repeaters, which are similar in appearance to magnetic compasses and are placed in the pilot house and at other points where knowledge of the ship’s heading is required. Gyrocompass equipment includes the master compass and its supports, batteries, a motor-generator set for supplying power in case of failure of the ship’s supply, instrument panel, and a panel for fuses and switches for the repeaters.
(b) The magnetic compass is in the pilot house. It is mounted in a compensating binnacle that neutralizes or compensates for errors introduced into the compass by the magnetic materials on the ship. (See figs. [8] and [9].)
(2) Pelorus. A pelorus is mounted on each wing of the navigating bridge. The pelorus is a graduated circle mounted in gimbals with an alidade pivoted over its center. It is used to measure directions to some distant point like another ship or an object on land. It gives the bearing relative to the ship’s heading or, if set to the ship’s true course, the true bearing to the object.
INBOARD PROFILE
Figure 6. Inboard profile of engineer port repair ship showing location of main installations.
INNER BOTTOM PLAN
Figure 7. Inner-bottom plan showing location of Diesel-oil, fresh-water, and salt-water tanks.