ISO 11674:2019

INTERNATIONAL ISO
STANDARD 11674
Third edition
2019-11
Ships and marine technology —
Heading control systems
Navires et technologie maritime — Systèmes de contrôle du cap
Reference number
ISO 11674:2019(E)
©
ISO 2019

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ISO 11674:2019(E)

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© ISO 2019
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ISO 11674:2019(E)

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions . 2
3.2 Abbreviated terms . 4
4 Requirements . 5
4.1 General . 5
4.2 Operational requirements . 7
4.2.1 Change-over from automatic to manual steering and vice versa. 7
4.2.2 Operational controls including adjustment controls. 7
4.2.3 Manual change-over from track control to heading control . 8
4.3 Functional requirements . 8
4.3.1 Rudder angle limitation . 8
4.3.2 Heading monitor . 8
4.3.3 Interfaces . 8
4.3.4 Alert management . 9
4.3.5 Mandatory displayed information .11
4.4 Control performance requirements .11
4.4.1 General.11
4.4.2 Heading keeping function under wave disturbance.12
4.4.3 Heading changing function .12
4.5 Display .14
5 Set-up .14
5.1 General .14
5.2 Ship motion simulator and starting condition .15
6 Tests of operational requirements .16
6.1 Change-over from automatic to manual steering and vice versa — Method of
testing and required test results .16
6.2 Operational controls including adjustment controls — Method of testing and
required test results .17
6.3 Manual change-over from track control to heading control .17
6.3.1 Application .17
6.3.2 Method of testing and required test results .17
6.4 Display test .18
7 Tests of functional requirements .18
7.1 Rudder angle limitation .18
7.1.1 Method of testing .18
7.1.2 Required test results .18
7.2 Heading monitor.18
7.3 Interfaces .19
7.3.1 Method of testing .19
7.3.2 Required test results .19
7.4 Alert management .19
7.4.1 Basic test for alert management .19
7.4.2 ‘Lost HDG control’ alert and escalation to BNWAS .19
7.4.3 ‘Off-heading’ alert.20
7.4.4 Alert detected by the heading monitor (‘Doubtful heading’ alert) .21
7.4.5 ‘No SPD adaptive’ alert .22
7.4.6 ‘Low speed’ alert .22
7.4.7 Failure or reduction in the power supply to the EUT or an external
heading monitor (‘HCS power fail’ alert) .23
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ISO 11674:2019(E)

7.4.8 System failure of EUT or an external heading monitor (‘HCS fault’ alert) .24
7.5 Mandatory displayed information — Method of testing and required test results .24
8 Tests of control performance .24
8.1 Heading keeping test under wave disturbance .24
8.1.1 Method of testing .24
8.1.2 Required test results .25
8.2 Heading changing test .25
8.2.1 Application .25
8.2.2 Small heading changing test .25
8.2.3 Heading changing test with preset turn rate .26
8.2.4 Heading changing test with preset turning radius .27
8.2.5 200° heading changing test .28
8.2.6 Heading changing test under wave disturbance .28
9 Information .29
Annex A (normative) Use of IEC 62065 ship models and wave disturbances for the HCS
performance tests .30
Annex B (normative) Alerts definition for HCS .43
Annex C (normative) IEC 61162 interfaces .44
Bibliography .47
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ISO 11674:2019(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology,
Subcommittee SC 6, Navigation and ship operations.
This third edition cancels and replaces the second edition (ISO 11674:2006), which has been technically
revised.
The main changes compared to the previous edition are as follows.
— Clause 1: The bridge alert management (BAM) requirement was added.
— Clause 2: The referenced documents such as related to BAM were added.
— Clause 3: Along with renewal of the overall structure of the document, the terms, definitions and
abbreviated terms were also updated.
— Clause 4: The IMO performance requirements that were defined in each clauses were summarized
in Clause 4. In addition, Clause 4 was classified into Operational requirements (4.2), Functional
requirements (4.3), and Control performance requirements (4.4) and the corresponding tests are
specified in Clause 6, Clause 7 and Clause 8.
— 4.3.4, 7.4, Annex B: Because the HCS becomes the BAM compliant equipment, alerts with a
standard alert identifier, BAM requirements, test methods, communication procedures, and other
requirements regarding implementation were added.
— Clause 5: To harmonize with IEC 62065:2014, the test procedure positively utilizing the ship motion
simulator of IEC 62065:2014 and the required test results were specified.
— Annex A: In connection with the change in Clause 8, the use of IEC 62065:2014 ship models and wave
disturbances for the HCS performance test was specified.
— The IEC 61162 interface requirements specified in the main body of this document were transferred
to Annex C, and details were specified.
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ISO 11674:2019(E)

Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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INTERNATIONAL STANDARD ISO 11674:2019(E)
Ships and marine technology — Heading control systems
1 Scope
This document specifies the minimum operational, functional and performance requirements, as well
as methods of testing and the corresponding required test results, for heading control systems installed
on board ships conforming to performance standards adopted by IMO Resolution MSC.64(67), Annex 3.
In addition, it takes into account parts of IMO resolution A.694(17) to which IEC 60945 is associated.
Also it takes into account IMO resolution MSC.302(87) on bridge alert management (BAM).
In this document, the ship models of simulators used for performance testing are based on those from
ships with a combined system of propeller propulsion and conventional rudder, with a speed range of
up to 30 knots.
The test results are considered also to be valid for ships with multiple parallel operated rudders.
NOTE The text in this document that is identical to that in IMO Resolution A.342(IX), as amended by IMO
Resolution MSC.64(67) Annex 3, and IMO Resolution A.694(17), is printed in italics.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 61162-1, Maritime navigation and radiocommunication equipment and systems — Digital interfaces —
Part 1: Single talker and multiple listeners
IEC 61162-2, Maritime navigation and radiocommunication equipment and systems — Digital interfaces —
Part 2: Single talker and multiple listeners, high-speed transmission
IEC 61162-450, Maritime navigation and radiocommunication equipment and systems — Digital
interfaces — Part 450: Multiple talkers and multiple listeners — Ethernet interconnection
IEC 62288, Maritime navigation and radiocommunication equipment and systems — Presentation of
navigation-related information on shipborne navigational displays — General requirements, methods of
testing and required test results
IEC 62065:2014, Maritime navigation and radiocommunication equipment and systems — Track control
systems — Operational and performance requirements, methods of testing and required test results
IEC 62923-1:2018, Maritime navigation and radiocommunication equipment and systems — Bridge alert
management — Part 1: Operational and performance requirements, methods of testing and required
test results
IEC 62923-2, Maritime navigation and radiocommunication equipment and systems — Bridge alert
management — Part 2: Alert and cluster identifiers and other additional features
IMO Resolution MSC.302(87), Performance standards for bridge alert management
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ISO 11674:2019(E)

3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp/
— IEC Electropedia: available at http:// www .electropedia .org/
3.1.1
adjustment control
control which changes the characteristics of an automatic heading (3.1.7) control unit
3.1.2
back-up navigator
individual, generally an officer, designated by the ship master to be on call if assistance is needed on
the bridge
[SOURCE: IMO Resolution MSC.74(69), Annex 2:1998, para 4]
3.1.3
change-over control
function for changing over from automatic to manual steering (3.1.10) and vice versa
3.1.4
central alert management
CAM
functionality for the management of the presentation of alerts on the CAM-HMI (3.1.5), the
communication of alert states between CAM-HMI and navigational systems and sensors
Note 1 to entry: The functions may be centralized or partly centralized in subsystems and interconnected via a
standardized alert-related communication.
[SOURCE: IMO Resolution MSC.302(87):2010, Appendix 1]
3.1.5
central alert management HMI
CAM-HMI
human machine interface for centralized presentation and handling of alerts on the bridge
[SOURCE: IMO Resolution MSC.302(87):2010, Appendix 1]
3.1.6
central alert management system
CAM system
combined functionality of CAM (3.1.4) and CAM-HMI (3.1.5)
[SOURCE: IEC 62923-1:2018, 3.1.18]
3.1.7
heading
direction in which the longitudinal axis of the ship is pointed, defined by the angle between the meridian
through its position and the fore-and-aft line of the ship, expressed in angular units from true north
Note 1 to entry: The heading is expressed in degrees from true north 000° clockwise through 360°, where 360°
becomes identical to 000°.
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ISO 11674:2019(E)

3.1.8
heading changing
function of the heading (3.1.7) control unit to change a ship’s heading towards the altered preset heading
(3.1.14) by taking the rudder order within the rudder limit, while if possible turning with a preset turn
rate or with a preset turning radius, within limits related to the ship's manoeuvrability
3.1.9
heading keeping
function of the heading (3.1.7) control unit to keep a ship’s heading at the preset heading (3.1.14) by
taking the rudder order within the rudder limit, within limits related to the ship's manoeuvrability
3.1.10
manual steering
method of controlling the steering gear manually
EXAMPLE Using a steering wheel.
3.1.11
off-heading
situation in heading keeping (3.1.9), where the ship’s heading (3.1.7) has deviated from the preset heading
(3.1.14) beyond a preset limit
3.1.12
overshoot
occurrence of a ship’s heading (3.1.7) response exceeding the preset heading (3.1.14) during heading
changing (3.1.8), when the preset heading is given as a step input to the HCS
Note 1 to entry: See Figure 1.
Key
Δh absolute value of overshoot
y ship’ s heading response relative to the previous preset heading during heading changing
k change of the preset heading
s
t time when ship's heading response reached the maximum value after exceeding k
m s
t time
Figure 1 — Overshoot
3.1.13
power supply
connection point of the HCS to the electrical system on board
Note 1 to entry: A power supply is an external interface to the HCS and may include any AC or DC voltage as
defined by the manufacturer. A HCS may have multiple power supplies.
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ISO 11674:2019(E)

3.1.14
preset heading
direction in which a ship is steered or intended to be steered as entered into the heading (3.1.7)
control system
Note 1 to entry: Preset heading is expressed as the angular direction in degrees from true north 000° clockwise
through 360°, where 360° becomes identical to 000°.
3.1.15
single operator action
one manual control
procedure achieved by no more than one hard-key or soft-key action, excluding any necessary cursor
movements, or voice actuation using programmed codes
[SOURCE: IMO Resolution MSC.302(87):2010, Appendix 1]
3.1.16
steering gear control system
SGCS
function that calculates and provides commands to the rudder actuator(s) to achieve the rudder angle
according to the rudder order provided
3.1.17
total power failure
absence of sufficient electrical voltage on all power supplies of the EUT
3.1.18
turning-radius control
method of controlling the rate of turn of a ship to perform turns with a preset turning radius through
the water
3.1.19
turn rate control
method of controlling the rudder of a ship to perform turns with a preset turn rate
3.1.20
undershoot
occurrence that during heading changing (3.1.8), the ship’s heading (3.1.7) has never reached the preset
heading (3.1.14) and the difference between the preset heading and the heading is not within the
specified range from the preset heading before/at specified time t
u
Note 1 to entry: See 4.4.3.1.
3.1.21
waypoint
geographic position together with its associated data
[SOURCE: IEC 62065:2014, 3.1.43]
3.2 Abbreviated terms
BAM bridge alert management
BNC back-up navigator call
BNWAS bridge navigational watch alarm system
CAM central alert management
CAM-HMI central alert management-human machine interface
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ISO 11674:2019(E)

CCW counterclockwise
CW clockwise
EUT equipment under test
HCS heading control system
HMI human machine interface
OOW officer of the watch
ROT rate of turn
SDME speed and distance measuring equipment
SGCS steering gear control system
SPD speed of ship
TCS track control system
UID user input device
4 Requirements
4.1 General
[IMO Resolution MSC.64(67), Annex 3, para 2.1] Within limits related to the ship's manoeuvrability the
heading control system, in conjunction with their sources of heading information, shall enable a ship to
keep a preset heading with minimum operation of the ship's steering gear.
[IMO Resolution MSC.64(67), Annex 3, para 2.3] A turn rate control or a turning-radius control for
performing turns may be provided.
NOTE The above IMO requirement (para 2.3) is interpreted as follows.
When the HCS performs the heading changing according to the preset heading, a turn rate (constant) control
for performing turns can be provided by setting either the maximum desired preset turn rate or the maximum
desired preset turning radius. (See IMO Resolution MSC.64(67), Annex 3, para 3.2).
[IMO Resolution MSC.64(67), Annex 3, para 3.1] 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.
A heading control system (HCS) shall be composed, as a minimum, of the following components (see
Figure 2).
a
— 4 components of HCS, in addition to an external heading monitor ( in Figure 2):
preset heading control, adjustment controls, serial/DIO interface ports, heading control unit.
— The heading control unit includes the following functions:
adjustment of control parameters (automatic/manual), heading keeping, display and indication of
mandatory/relevant information, alert management. If possible, heading changing with preset turn
rate or with preset turning radius. If applicable, automatic adaption control to ship speed (change)
b
and/or disturbances, an internal heading monitor ( in Figure 2).
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ISO 11674:2019(E)

— The alert management includes the following functions:
alert activation, alert presentation, alert handling, alert communication with CAM system, self-
diagnostic function to notify OOW.
Key
δo rudder order
δ actual rudder angle
a
In case the heading monitor is (a function of) an external device. (e.g. heading information system composed
of multiple heading sensors and heading distribution unit).
b
In case the heading monitor is an internal function of the heading control unit.
c
Manual devices for example include a steering wheel and steering UIDs installed on the bridge.
d
Plural SG control units are usually installed to drive hydraulic power units of steering gear.
e
Steering gear usually includes the plural hydraulic power units.
f
When the HCS utilizes speed information for automatic heading control adaptation.
For example: an autopilot adaptive to speed; a HCS with turning-radius control.
g
When a ship simulator is used for test, the part surrounded by a dash-dotted line is replaced by
IEC 62065:2014 ship motion simulator.
NOTE 1 During the tests, the CAM system can be replaced by a CAM simulator.
NOTE 2 During the tests, the BNWAS can be replaced by a simulator.
NOTE 3 Dotted line: equipment/function is optional.
NOTE 4 Dashed line: not part of the system to be tested in this document.
Figure 2 — Typical block diagram for a heading control system installed on the bridge
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ISO 11674:2019(E)

4.2 Operational requirements
4.2.1 Change-over from automatic to manual steering and vice versa
[IMO Resolution MSC.64(67), Annex 3, para 4.1] Change-over from automatic to manual steering and vice
versa shall be possible at any position of the rudder and s
...