Compass Adjustment
REFLECTA/5
Page C1
Mounting & Operations Manual
Adjustment of the Compass
General
Compass adjustment is necessary to neutralize the deflecting magnetic fields caused by the ship´s steel hull or
superstructure.
The first adjustment has to be made on maiden voyage. Later, it should be repeated periodically according to
the requirements of the maritime authority. Furthermore it should be carried out additionally on particular
circumstances like reconstruction works, lightning stroke, grounding .....
It is necessary to call a qualified compass adjuster for adjustment works.
Before adjustment the vessel must be ready for sea: cargo derricks, hatchway covers, davits.....are to be
positioned as on voyage.
Further details will be found in “Handbook of Compass Adjustment“, Pub. 226 of U.S. Department of Defense,
Defense Mapping Agency.
A-Correction
This is to correct the alignment error of the compass binnacle: Compass ahead and ships ahead have to be
corresponding. For correction loosen the binnacle fixing bolts in the base. Oblong holes in the base allow to turn
the binnacle column by +/-5° around its vertical axis.
Separate B+C-Correction magazines (#18100, Extra)
B+C are for adjustment of the permanent longitudinal and cross ship field.
3 pcs of varnished wooden magazines with 6 pcs ISO magnets (200 mm long x 10 mm
∅
). The magnets are
stored within one of the magazines.
This corrector arrangement adjusts about 35° of deviation if compass and magazines are mounted as directed.
Unscrew the side covers to make out the drillings to insert the magnets.
For B-adjustment install one each magazine at port and starboard of the compass as to be seen from the
following drawing 1. The magnets have to be exact parallel to ship´s longitude.
The remaining C-magazine can be fixed ahead or aft of the compass. The magnets have to be exact to ship´s
cross direction.
The distance between the nearest points of compass and corrector magazine should be 200 mm.The magazine
plane may be orientated horizontal, vertical or every angle between (drawing 2). It is essential to have the B-
magnets parallel to ship´s longitudinal direction and the C-magnets parallel to ship´s cross direction. Protect the
magazines against water!
After Installation adjustment of compass by a professional compass adjuster is necessary.
Drawing 1) Arrangement as to be seen from above
Voraus
Ahead
B-magnets, longitudinal
B-Magnete, längsschiffs
B-magnets,
exact longitudinal
B-Magnete,
Compass Column
Kompass Säule
abt. 20 cm
ca. 20 cm
exakt längsschiffs
C-magnets, cross orientated.
Magazine also alternatively to
install ahead of compass
C-Magnete, querschiffs.
Tasche kann auch voraus vom
Kompass montiert sein.
Alterations / Errors reserved
Cassens & Plath GmbH, Am Lunedeich 131, 27572 Bremerhaven, Germany, Tel. +49 471 483 999 0, Fax +49 471 483 999 10
www.cassens-plath.de
