ISO 11674:2000

INTERNATIONAL ISO
STANDARD 11674
First edition
2000-07-15
Ships and marine technology — Heading
control systems
Navires et technologie maritime — Systèmes de pilotage
Reference number
ISO 11674:2000(E)
©
ISO 2000

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ISO 11674:2000(E)
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ISO 11674:2000(E)
Contents Page
Foreword.iv
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Performance.3
4.1 General.3
4.2 Constituents.3
4.3 Functional requirements.3
4.4 Safety precautions.7
5 Type testing.7
5.1 Testing and required results .7
5.2 Magnetic compass safe distance test .7
5.3 EMC and environmental tests .7
5.4 Change-over from automatic to manual steering mode.7
5.5 Control characteristic.8
6 Marking and identification .9
7 Information .9
Annex A (normative) Ship-motion simulator.10
Annex B (informative) Equivalent requirements in ISO/FDIS 11674 and IMO Resolutions .12
Bibliography.13
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ISO 11674:2000(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 11674 was prepared jointly by Technical Committee ISO/TC 8, Ships and marine
technology, Subcommittee SC 6, Navigation and IEC/TC 80, Maritime navigation and radiocommunication
equipment and systems.
This first edition cancels and replaces ISO/TR 11674:1996.
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INTERNATIONAL STANDARD ISO 11674:2000(E)
Ships and marine technology — Heading control systems
1 Scope
This International Standard specifies the structure, performance, inspection and testing of heading control systems
to be installed on board ships.
It applies to the heading control systems which enable a ship to keep a preset heading with minimum operation of
the ship's steering gear, within limits related to the ship's manoeuvrability in conjunction with their sources of
heading information.
The heading control system may work together with a track control system adjusting its heading for drift.
A turn rate control or a turning-radius control for performing turns may be provided.
NOTE All the text in this International Standard identical to that in IMO Resolutions [Resolution A.342(IX) as amended by
resolution MSC.64(67), annex 3 and Resolution A.694(17)] are printed in italics.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 694:2000, Ships and marine technology — Positioning of magnetic compasses in ships.
IEC 60945:1996, Maritime navigation and radiocommunication equipment and systems — General requirements —
Methods of testing and required test results.
IEC 61162, Maritime navigation and radiocommunication equipment and systems — Digital interfaces.
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
3.1
adjustment control
device which changes the characteristics of an automatic steering device, including proportional rudder adjustment,
derivative rudder adjustment, integral rudder adjustment and weather adjustment
NOTE The term "derivative rudder adjustment" is also called "counter rudder adjustment" customarily.
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ISO 11674:2000(E)
3.2
automatic steering
method of controlling the steering gear automatically to enable a ship to keep a preset heading, processing the
heading information which is obtained from a gyro-compass or magnetic compass, etc.
3.3
automatic-steering device
device which controls automatic steering
3.4
change-over device
device for changing over from automatic to manual steering and vice versa
3.5
derivative rudder adjustment
counter rudder adjustment
adjustment of a component of the total rudder command which acts to control the rate of turn of the ship
3.6
heading
horizontal direction in which a ship actually points or heads at any instant
NOTE Heading is expressed in degrees from a reference direction, usually from 000° at the reference direction clockwise
through 360°.
3.7
heading-signal processor
unit which processes the heading signal generated by a gyro-compass, magnetic compass, etc., and adapts it
before its use by the heading control system
3.8
integral rudder adjustment
adjustment of a component of the total rudder command which is in proportion to the integral value of the heading
deviation
3.9
manual steering
method of controlling the steering gear manually
EXAMPLE Using a steering wheel.
3.10
operational device
switch, key, knob, etc. which is used for operating a heading control system
3.11
preset heading
horizontal direction in which a ship is steered or intended to be steered
NOTE Preset heading is expressed as the angular direction in degrees with respect to north (true/magnetic), from 000°
clockwise through 360°.
3.12
proportional rudder adjustment
adjustment of a component of the total rudder command in proportion to an instantaneous value of the difference
between the preset heading and actual heading
3.13
turning-radius control
method of controlling the rate of turn of a vessel to perform turns with a preset turning radius through the water
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ISO 11674:2000(E)
3.14
turn-rate control
method of controlling the rudder of a vessel to perform turns with a preset rate of turn
3.15
weather adjustment
adjustment which minimizes unnecessary steering motion against yawing caused by waves, swells and wind
4 Performance
4.1 General
4.1.1 The heading control system shall be capable of adapting manually or automatically to different steering
characteristics of the ship under various speed, weather and loading conditions, and provide reliable operation
under prevailing environment and normal operational conditions.
4.1.2 Heading control systems shall conform to the environmental requirements of IEC 60945 for equipment
categories protected from the weather.
4.2 Constituents
A heading control system shall be composed, as a minimum, of the following components (see Figure 1):
a) heading-signal processor (including an indicator of the heading);
b) operational control for preset heading;
c) operational controls for adjustments;
d) automatic steering device;
e) change-over device (with steering-mode indicator) which is not required to be an integrated part of the heading
control system;
f) alarm signalling facilities compliant with the requirements of this International Standard;
g) indicators for steering mode and heading source in use.
4.3 Functional requirements
4.3.1 Change-over from automatic to manual steering and vice versa
4.3.1.1 Change-over from automatic to manual steering and vice versa shall be possible at any position of the
rudder and shall be activated by one manual control within 3 seconds.
4.3.1.2 Change-over from automatic to manual steering shall be possible under any conditions including any
failure in the heading control system.
4.3.1.3 When changing-over from manual to automatic steering, if there is no new safe input of command, the
heading control system shall take over the actual heading of this time as the preset heading.
4.3.1.4 There shall be a single change-over control which shall be located in such a position that it is easily
accessible to the officer of the watch.
4.3.1.5 Adequate indication shall be provided to show which method of steering is in operation at a particular
moment. This indicator shall be fitted near the change-over.
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ISO 11674:2000(E)
a The portion enclosed by the thick line shows the constituent devices of a heading control system which are specified in this
International Standard.
b The change-over device is not required to be an integrated part of the heading control systems.
c Alarm indicating devices may be external units.
Figure 1 — Typical block diagram for heading control system
4.3.2 Operational controls including adjustment controls
4.3.2.1 All operational controls shall permit normal adjustments to be easily performed and shall be easy to
identify from the position at which the equipment is normally operated. Controls not required for normal operation
shall not be readily accessible.
4.3.2.2 The number of operational controls shall be such that easy and safe operation can be achieved. The
controls shall be designed and arranged to preclude inadvertent operation. Their manner of functioning, location
and size shall provide for simple, quick and effective operation.
4.3.2.3 Adequate illumination shall be provided in the equipment or in the ship to enable identification of controls
and facilitate reading of indicators at all times. Means shall be provided for dimming the output of the light source
which is capable of interfering with navigation.
4.3.2.4 Unless features for automatic adjustment are incorporated in the installation, the heading control system
shall be provided with adequate controls to adjust its performance to effects due to weather and the ship's steering
performance.
4.3.2.5 The heading control system shall be designed in such a way as to ensure altering the preset heading to
starboard by turning the heading setting control clockwise or tilting it to the right-hand side. Turning the control
counterclockwise or tilting it to the left shall effect a similar alteration to port. Normal alterations of heading shall be
possible by one adjustment only of the preset heading control. Requirements shall be made by means of the
design and the construction of the preset heading control to preclude unintended alteration of heading.
4.3.2.6 When changing heading, the clockwise or counterclockwise direction of preset heading adjustment shall
determine the ship's turning direction.
4.3.2.7 Where remote control stations are provided, facilities for the delegation of control to the remote station and
unconditional return of control shall be incorporated in the master station.
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ISO 11674:2000(E)
4.3.2.8 Except for the preset heading setting control, the actuation of any other control shall not significantly affect
the heading of the ship.
4.3.2.9 Additional controls at remote positions shall comply with the provisions of this standard.
4.3.3 Rudder angle limitation
Means shall be incorporated in the equipment to enable adjustable rudder angle limitation in the automatic mode.
Means shall also be available to indicate
...