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IS0
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION
IS0 RECOMMENDATION
R 694
POSITIONING OF MAGNETIC COMPASSES IN SHIPS
1st EDITION
March 1968
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.
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BRIEF HISTORY
The IS0 Recommendation R 694, Positioning of magnetic compasses in ships, was drawn up by
Technical Committee ISO/TC 8, Shipbuilding details, the Secretariat of which is held by the
Netherlands Normalisatie-instituut (NNI).
Work on this question by the Technical Committee began in 1958 and led, in 1965, to the
adoption of a Draft IS0 Recommendation.
In October 1965, this Draft IS0 Recommendation (No. 858) was circulated to all the IS0
Member Bodies for enquiry. It was approved, subject to a few modifications of an editorial nature,
by. the following Member Bodies :
Argentina Sweden
Finland
Australia India U.A.R.
Austria Ireland United Kingdom
Belgium Israel U.S.S.R.
Brazil Netherlands Yugoslavia
Canada New Zealand
Czechoslovakia Spain
Four Member
Bodies opposed the approval of the Draft :
France
Germany
Italy
Japan
The Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council,
which decided, in March 1968, to accept it as an IS0 RECOMMENDATION.
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ISO/R 694-1968 (E)
March 1968
IS0 Recommendation R 694
POSITIONING OF MAGNETIC COMPASSES IN SHIPS
INTRODUCTION
In order to obtain satisfactory and durable compensation of compasses, this IS0 Recommendation
should be taken into consideration during the design stage of a ship.
1. GENERAL
1.1 Scope
This IS0 Recommendation deals with the installation in ships of magnetic compasses and
binnacles complying with the requirements of the following IS0 Recommendations :
ISO/R 449, Magnetic compasses and binnacles, Class A, for use in sea navigation;
ISO/R 613, Magnetic compasses, binnacles and azimuth reading devices, Class B,
General requirements.
In addition, it covers magnetic elements used in navigational aids.
It should be noted that this IS0 Recommendation is established only for general purposes.
It is not necessarily applicable to all sea-going ships.
1.2 Compass positions
The specifications governing the minimum distance of a compass from magnetic material take
into consideration the accuracy required of that compass for normal navigation.
1.3 Safe distances
Safe distances from the compass are prescribed for magnetic and electrical equipment and
inductive circuits. They are defined as the minimum distances considered necessary for any of
these items in order to eliminate or greatly reduce interference with the performance ofthe
compass.
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ISO/R 694-1968 (E)
1.4 Accuracy of magnetic compasses
The reliability and accuracy of magnetic compasses are dependent to a great extent upon their
position in the ship and upon the proximity of magnetic and electrical equipment in relation to
that position. Varying degrees of reliability and accuracy are, however, permitted, dependent
on the function the compass is intended to perform and the overall length of the ship in which
it may be installed.
2. FUNCTIONS OF MAGNETIC COMPASSES
Magnetic compasses are classified according to the functions they are intended to perform in ships. In
the following description of the functions of the standard magnetic compass no account has been
taken of the possible fitting of one or more gyro-compasses in the ship. The fitting of a gyro-compass
should not be taken as a reason for reducing in any way the accuracy to be expected from the ship’s
standard magnetic compass, which is the primary means of navigating the ship.
The main functions of magnetic compasses in ships are defined as follows :
2.1 Standard compass
Magnetic compass which provides the primary means of navigating a ship.
If there is only one magnetic compass, it is the standard compass.
Such a compass, or a repeater from it, should be sited in the vicinity of the position from which
the ship is ordinarily navigated and the view of the horizon from this position should be as
uninterrupted as possible, for the purpose of taking bearings. In the sector from right ahead to
115” on either side, the view of the horizon may be interrupted only by masts,derrick posts,
cranes and similar obstructions.
2.2 z Steering compass
Magnetic compass which provides the primary means by which the ship is steered. If the
standard compass sited on the wheelhouse top is of the projector or reflector type, it may also
act as the steering compass.
2.3 Stand-by steering and emergency compasses (if fitted)
Magnetic compasses which provide the secondary means by which the ship is steered.
An example of a stand-by steering compass is envisaged, such as a steering compass fitted in a
ship’s wheelhouse wherein the reflected or projected image of the standard compass is already
available, and principally used for steering.
An emergency compass is one fitted for the purpose of conning or steering the ship after
damage or breakdown of all other means of doing so.
2.4 Magnetic elements
Used in navigational aids, they are not used for one of the purposes defined in clauses 2.1,
2.2 and 2.3.
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ISO/R 694-1968 (E:
3. MINIMUM DISTANCE REQUIREMENTS CONCERNING
THE SHIP’S STRUCTURE
3.1 The stundard compass should be so positioned that it complies with the minimum distance
requirements for magnetic material which may be regarded as part of the ship’s structure, as
indicated in the diagram. Any magnetic material in the vicinity of the compass but outside of
the minimum distances (see diagram) should be disposed symmetrically relative to the compass.
It is emphasized that these distances are minimum permissible distances and should prove satis-
NOTE. -
factory in the majority of ships. Special cases will, however, arise, where the masses of iron in the vicinity of
the compass are such that the compass does not work satisfactorily and in these cases the distances should of
necessity be increased.
3.2 For the steering compasses, the distance in the diagram may be reduced to 65 o/o and for
stand-by steering compasses and magnetic ‘elements referred to in clause 2.4 to 50 ‘lo of those
required for the standard compass, provided that no distance is less than 1 .O m.
For emergency compasses (if fitted), the minimum distance is 1.0 m.
3.2.1 For steering compasses, the distance from the deck below the compass may be reduced to
1 .O m provided the distance from the extremities of the iron decks, bulkheads and girders is
not less than 65 o/o of the distances shown in the diagram for the standard compass.
3.3 Items which are permanently fixed to the ship’s structure should be tre
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