IEC 61892-5:2010
(Main)Mobile and fixed offshore units - Electrical installations - Part 5: Mobile units
Mobile and fixed offshore units - Electrical installations - Part 5: Mobile units
IEC 61892-5:2010(E) specifies the characteristics for electrical installations in mobile units, for use during transfer from one location to another and for use during the exploration and exploitation of petroleum resources. It applies to all installations, whether permanent, temporary, transportable or hand-held, to a.c. installations up to and including 35 000 V and d.c. installations up to and including 1500 V.(a.c. and d.c. voltages are nominal values). This edition cancels and replaces the first edition published in 2000. This edition includes the following significant technical changes with respect to the previous edition:
a) the requirement to d.c. generators has been deleted;
b) the requirement to EMC has been rewritten;
c) the requirement to power management system has been added;
d) an informative annex regarding testing of DP systems has been added.
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Standards Content (Sample)
IEC 61892-5 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
Mobile and fixed offshore units – Electrical installations –
Part 5: Mobile units
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IEC 61892-5 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
Mobile and fixed offshore units – Electrical installations –
Part 5: Mobile units
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
W
ICS 47.020.60 ISBN 978-2-88912-153-3
– 2 – 61892-5 © IEC:2010(E)
CONTENTS
FOREWORD.5
INTRODUCTION.7
1 Scope.8
2 Normative references .8
3 Terms and definitions .9
4 General requirements .10
4.1 Protection against flooding .10
4.2 Rotating machines.10
4.3 Conductors, equipment and apparatus .10
4.4 Main switchboards.10
4.5 Precautions against vibration and mechanical shock .11
4.6 Axes of rotation .11
5 Limits of inclination of the unit .11
5.1 Authority requirement .11
5.2 Machines, equipment and apparatus – General .11
5.3 Propulsion machinery .11
5.4 Emergency machinery .11
5.5 Dynamic condition .11
6 Bilge pumps .12
6.1 Power supply.12
6.2 Cables and cable connections .12
6.3 Location of starting arrangement .12
7 Navigation lights.12
7.1 General .12
7.2 Navigation lights when in operation .12
7.3 Steaming lights .12
7.4 Collision regulations .12
7.5 Power supply and monitoring systems.13
7.6 Special requirements for lights using LEDs.13
8 Steering gear.13
8.1 Power operated steering gear.13
8.2 Motors.14
8.3 Motor starters.14
8.4 Power circuits supply.14
8.5 Supply of control circuits and control systems .14
8.6 Circuit protection .15
8.7 Starting and stopping of motors for steering gear power units .15
8.8 Steering gear control systems .15
8.9 Alarms and indications .15
8.10 Rudder angle indication.16
8.11 Separation of circuits.16
8.12 Communication between navigating bridge and steering gear compartment .16
9 Electric propulsion.16
9.1 General .16
9.2 General requirements.17
9.2.1 Torque and critical speeds.17
61892-5 © IEC:2010(E) – 3 –
9.2.2 Lubrication .18
9.2.3 Prime movers .18
9.3 Electromagnetic compatibility (EMC) and harmonic distortion .19
9.3.1 General .19
9.3.2 Total harmonic distortion, THD .19
9.3.3 Radio frequency interference.19
9.4 Harmonic filtering .19
9.5 Generators, motors, semiconductor convertors and electric slip-couplings .20
9.5.1 Machine and equipment temperature and ventilation .20
9.5.2 Accessibility and facilities for repair in situ.20
9.5.3 Protection against moisture and condensate.21
9.5.4 Sudden short circuits .21
9.5.5 Overspeed of propulsion motors .21
9.5.6 Exciter sets .21
9.5.7 Semiconductor convertor design data .21
9.6 Protection against moisture and condensation.22
9.7 Controlgear .22
9.7.1 Location of manoeuvring controls .22
9.7.2 Engine order systems .22
9.7.3 Operation of manoeuvring controls .22
9.7.4 Interlocking of the means of control .23
9.8 Cables and wiring.23
9.8.1 Conductors.23
9.8.2 Internal wiring.23
9.8.3 Bus-bars.23
9.9 Main and control circuits.23
9.9.1 Control .23
9.9.2 Power management system.24
9.9.3 Circuitry and components .26
9.10 Protection of the system .26
9.10.1 Protection.26
9.10.2 Instrumentation.27
9.11 Propulsion transformers .28
9.12 Testing .28
10 Dynamic positioning .28
11 Ballast systems .28
11.1 General .28
11.2 Ballast pumps.29
11.3 Control and indicating systems.29
11.4 Internal communication .30
11.5 Protection against flooding .30
12 Jacking systems .30
12.1 General .30
12.2 Design.30
12.3 Holding capacity.31
12.4 Electric motor capacity .31
12.5 Control and monitoring .31
12.6 Jacking gear motors and motor controller .31
12.6.1 General .31
– 4 – 61892-5 © IEC:2010(E)
12.6.2 Group installation .31
12.6.3 Overcurrent protection.32
12.6.4 Running protection .32
12.6.5 Metering .32
12.7 Testing onboard .32
13 Anchoring systems .32
13.1 General .32
13.2 Anchoring arrangements .32
13.3 Control systems .32
13.4 Thruster-assisted anchoring systems (TA).33
Annex A (informative) Enhanced system verification test (HIL test).34
Bibliography.36
Figure 1 – Typical equipment (configuration) for unit with one or two propellers.17
Figure 2 – Typical control configuration .25
61892-5 © IEC:2010(E) – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MOBILE AND FIXED OFFSHORE UNITS –
ELECTRICAL INSTALLATIONS –
Part 5: Mobile units
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61892-5 has been prepared by IEC technical committee 18:
Electrical installations of ships and of mobile and fixed offshore units.
This second edition cancels and replaces the first edition published in 2000. This edition
constitutes a technical revision.
This second edition includes the following significant technical changes with respect to the
previous edition:
a) the requirement to d.c. generators has been deleted;
b) the requirement to EMC has been rewritten;
c) the requirement to power management system has been added;
d) an informative annex regarding testing of DP systems has been added.
– 6 – 61892-5 © IEC:2010(E)
The text of this standard is based on the following documents:
FDIS Report on voting
18/1167/FDIS 18/1177/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The requirements specified in this International Standard are based on the Code for the
Construction and Equipment of Mobile Offshore Drilling Units (1989 MODU CODE) published
by the International Maritime Organization (IMO), and might include additional provisions.
A list of all the parts in the IEC 61892 series, under the general title Mobile and fixed offshore
units – Electrical installations, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under “http://webstore.iec.ch” in the data
related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this standard may be issued at a later date.
61892-5 © IEC:2010(E) – 7 –
INTRODUCTION
IEC 61892 forms a series of International Standards intended to ensure safety in the design,
selection, installation, maintenance and use of electrical equipment for the generation,
storage, distribution and utilization of electrical energy for all purposes in offshore units used
for exploration or exploitation of petroleum resources.
This standard is based on equipment and practices which are in current use, but it is not
intended in any way to impede development of new or improved techniques.
The ultimate aim has been to produce a set of International Standards exclusively for the
offshore petroleum industry.
– 8 – 61892-5 © IEC:2010(E)
MOBILE AND FIXED OFFSHORE UNITS –
ELECTRICAL INSTALLATIONS –
Part 5: Mobile units
1 Scope
This part of IEC 61892 specifies the characteristics for electrical installations in mobile units,
for use during transfer from one location to another and for use during the exploration and
exploitation of petroleum resources.
It applies to all installations, whether permanent, temporary, transportable or hand-held, to
a.c. installations up to and including 35 000 V and d.c. installations up to and including
1500 V.(a.c. and d.c. voltages are nominal values).
NOTE Attention is drawn to further requirements concerning electrical installations on such mobile offshore units
contained in the MODU CODE of the International Maritime Organization (IMO).
2 Normative references
The following referenced documents are indispensable for the application 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 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60034-6, Rotating electrical machines – Part 6: Methods of cooling (IC Code)
IEC 60076 (all parts), Power transformers
IEC 60092-501:2007, Electrical installations in ships – Part 501 Special features – Electric
propulsion plant
IEC 60092-504, Electrical installations in ships – Part 504 Special features – Control and
instrumentation
IEC 60332-1-2, Tests on electric and optical fibre cables under fire conditions – Part 1-2: Test
for vertical flame propagation for a single insulated wire or cable – Procedure for 1 kW pre-
mixed flame
IEC 60332-3-22, Tests on electric cables under fire conditions – Part 3-22: Test for vertical
flame spread of vertically-mounted bunched wires or cables – Category A
IEC 61000-6-2:2005, Electromagnetic compatibility (EMC) – Part 6-2: Generic standards –
Immunity for industrial environments
IEC 61378-1, Convertor transformers – Part 1: Transformers for industrial applications
IEC 61892-1, Mobile and fixed offshore units – Electrical installations – Part 1: General
requirements and conditions
IEC 61892-2, Mobile and fixed offshore units – Electrical installations – Part 2: System design
61892-5 © IEC:2010(E) – 9 –
IEC 61892-3, Mobile and fixed offshore units – Electrical installations – Part 3: Equipment
IEC 61892-6, Mobile and fixed offshore units – Electrical installations – Part 6: Installation
IMO-110E, IMO-111F and IMO-113S, International Convention for the Safety of Life at Sea
(SOLAS)
IMO Guidelines for vessels with dynamic positioning systems – see IMO/MSC/Circ. 645,
Annex, International Maritime Organization
IMO 904E, Convention on the International Regulations for Preventing Collisions at Sea,
International Maritime Organization (COLREG)
3 Terms and definitions
For the purposes of this document the terms and definitions given in IEC 61892-1,
IEC 61892-2, IEC 61892-3, IEC 61892-6 and the following apply.
3.1
auxiliary steering gear
equipment, other than any part of the main steering gear, necessary to steer the unit in the
event of failure of the main steering gear but not including the tiller, quadrant or components
serving the same purpose
3.2
dynamic positioning (DP) system
equipment necessary to provide means of controlling the position and heading of a mobile
unit within predetermined limits by means of resultant vectored thrust
3.3
electric steering gear
power operated steering gear where an electric motor applies torque to the rudder stock
through mechanical means only
3.4
electrohydraulic steering gear
power operated steering gear where a hydraulic pump, driven by an electric motor, applies
torque to the rudder stock through hydraulic and mechanical means
3.5
main steering gear
machinery, rudder actuators, steering gear power units and ancillary equipment and the
means of applying torque to the rudder stock (for example tiller or quadrant) necessary for
effecting movement of the rudder for the purpose of steering the unit under normal service
conditions
3.6
petroleum
complex mixture of hydrocarbons that occurs in the earth in liquid or gaseous forms
3.7
propulsion machine (electric)
rotating machine normally intended to provide propulsive power
– 10 – 61892-5 © IEC:2010(E)
3.8
redundancy
in an item, the existence of more than one means for performing a required function
[IEC 60050-191:1990, 191-15-01]
3.9
semiconductor convertor
an electronic power converter with semiconductor valve devices
[IEC 60050-551:1998, 551-12-42]
3.10
steering gear control system
equipment by which orders are transmitted from the navigating bridge to the steering gear
power units
NOTE Steering gear control systems comprise transmitters, receivers, hydraulic control pumps and their
associated motors, motor controllers, piping and cables, etc.
3.11
steering gear power unit (electric steering gear)
electric motor and its associated electrical equipment used to operate the steering gear
3.12
steering gear power unit (electrohydraulic steering gear)
electric motor and its associated electrical equipment and connected pump used to operate
the steering gear
4 General requirements
4.1 Protection against flooding
In every mobile unit in which electric power is used for the services necessary for the safety
of the unit, the generators, switchgear, motors and associated controlgear for such services,
with the exception of machinery in the platform of semi-submersibles, shall be so situated or
arranged that they continue to operate satisfactorily in the event of partial flooding by bilge
water above the tank top in the space in which they are situated.
4.2 Rotating machines
Rotating machines shall be installed to minimise the effects of motion. The design of bearings
of all machines and the arrangement for their lubrication shall be adequate to withstand the
motions encountered in heavy weather and operation for prolonged periods at the list and trim
specified in Clause 5 without the spillage of oil.
4.3 Conductors, equipment and apparatus
Conductors, equipment and apparatus shall be placed at such a distance from each magnetic
compass or shall be so disposed that the interfering external magnetic field is negligible; that
is, the total singular deviation shall not exceed 30 min when any combination of circuits is
switched on and off.
4.4 Main switchboards
The main switchboard shall be subdivided into at least two parts. The subdivision may be
effected by removable links, circuit-breakers or other suitable means so that the main
generators and any supplies to duplicated services which are directly connected to the
busbars are, as far as is practicable, equally divided between the sections.
61892-5 © IEC:2010(E) – 11 –
4.5 Precautions against vibration and mechanical shock
Machines, equipment and apparatus shall be unaffected by vibration and shock likely to arise
under normal service. Screws and nuts securing current-carrying parts shall be effectively
locked so that they cannot work loose by vibration. The locking of screws and nuts securing
noncurrent-carrying parts is recommended where necessary.
4.6 Axes of rotation
For units where the requirements to dynamic conditions, as specified in 5.5 apply, horizontal
rotation machines shall to the extent possible be installed preferably with the shaft in the fore-
and-aft direction. Where a machine is installed athwartship, it shall be ensured that the design
of the bearings and the arrangements for lubrication are satisfactory to withstand the rolling
specified in Clause 5. The manufacturer shall be informed when a machine for installation
athwartship is ordered.
5 Limits of inclination of the unit
5.1 Authority requirement
Dependent upon the outcome of all studies relevant to the intact and damaged stability of the
unit, the appropriate authority may require or permit deviations from the angles stated in 5.2,
5.3 and 5.4.
5.2 Machines, equipment and apparatus – General
All machines, equipment and apparatus shall operate satisfactorily under all conditions with
the unit upright and when inclined up to the following angles from the normal:
− for column stabilized units, 15° in any direction;
− for self-elevating units, 10° in any direction;
− for surface units, 15° either way in list and simultaneously trimmed 5° by the bow or stern.
5.3 Propulsion machinery
Main propulsion machinery and all auxiliary machinery essential to the propulsion and safety
of the mobile unit shall be capable of operating under the static conditions specified in 5.2 and
the following dynamic conditions:
– for column stabilized units, 22° 30′ in any direction;
– for self-elevating units, 15° in any direction;
– for surface units, 22° 30′ rolling and simultaneously pitching 7° 30′ by the bow or stern.
5.4 Emergency machinery
Emergency machines, equipment and apparatus fitted in accordance with requirements from
the appropriate authority for emergency plant shall operate satisfactorily under all conditions
with the unit upright and when inclined up to the following maximum angles from the normal:
– for column stabilized units, 25° in any direction;
– for self-elevating units, 15° in any direction;
– for surface units, 22° 30′ about the longitudinal axis and/or when inclined 10° about the
transverse axis.
5.5 Dynamic condition
Where required by the appropriate authority, dynamic condition limits shall apply as follows:
– 12 – 61892-5 © IEC:2010(E)
– rotation about fore-and-aft axis (rolling), ±22° 30′ ;
– rotation about athwartship (pitching), ±7° 30′ .
NOTE These motions may occur simultaneously.
6 Bilge pumps
6.1 Power supply
Motors of permanently installed emergency bilge pumps, if any, shall be connected to an
emergency switchboard.
6.2 Cables and cable connections
Cables and their connections to submersible pumps shall be capable of operating under a
head of water equal to their distance below the worst damaged condition waterline. The
cables shall either be armoured or mechanically protected by other means and shall not be
installed within the assumed extent of damage. They shall be installed in continuous lengths
from above the worst damaged condition waterline to the motor terminals, entering the air-bell
from its underside.
6.3 Location of starting arrangement
Under all circumstances it shall be possible to start the motor of a permanently installed bilge
pump from a convenient point above the worst damaged condition waterline and in a space
not within the assumed extent of damage.
NOTE Information regarding the worst damaged condition waterline and the spaces within the assumed extent of
damage is given in IMO requirements.
7 Navigation lights
7.1 General
Except when a unit is stationary and engaged in operations, attention is drawn to IMO 904E.
7.2 Navigation lights when in operation
When a unit is stationary and engaged in operations, attention is drawn to the requirements
for the safety of navigation of the coastal state in whose territorial sea or on whose
continental shelf the unit is operating.
NOTE Unless otherwise required for the obstruction lighting by national authorities, the lighting is to be in
accordance with the requirements of IALA.
7.3 Steaming lights
All units shall be provided with "steaming lights" which comprise masthead, side, stern,
anchor, not-under-command and, if applicable, special-purpose lights. The construction and
installation of navigation lights shall be to the satisfaction of the appropriate authority.
7.4 Collision regulations
Attention is drawn to the Collision Regulations in relation to the provision of primary and
alternative lanterns for each of the navigation lights.
61892-5 © IEC:2010(E) – 13 –
7.5 Power supply and monitoring systems
The following electrical arrangements relate only to the navigation lights referred to in 7.3 and
7.4.
– Each light shall be connected by a separate cable to a distribution board reserved solely
for navigation lights, fitted in an accessible place under the control of watchkeeping
personnel.
– There shall be two separate power supply systems to the distribution board, one being
from the main switchboard and one from the emergency switchboard. Where a transitional
source of emergency power is required by the Safety of Life at Sea (SOLAS) Convention,
the arrangements shall enable the lights to be supplied from this source in addition to the
emergency switchboard. An alarm shall be activated in the event of failure of a power
supply to the distribution board.
– As far as practicable, the arrangements should be such that a fire, a fault or mechanical
damage at any one point will not render both systems inoperative. It is, however, accepted
that the systems must come together at some point where the changeover can be
performed. This should, preferably, be at or near to the distribution board.
– Each light shall be controlled and protected in each insulated pole by a switch and fuse or
by a circuit-breaker mounted in the distribution board.
– Each light shall be provided with an automatic indicator to give an acoustic and/or optical
alarm in the event of complete extinction of the light. If an optical signal is used, which is
connected in series with the steaming light, means to prevent failure of the indicator
extinguishing the steaming light shall be provided. If an acoustic device alone is used it
shall be connected to an independent source of supply, for example a battery, and
provision shall be made for testing this supply.
NOTE The use of junction boxes in navigation light circuits, other than those provided for connecting the lanterns
to the fixed wiring of the electrical installation, should be avoided. Cables for different circuits should not use the
same junction box.
7.6 Special requirements for lights using LEDs
The luminous intensity of LEDs gradually decreases while the electricity consumption remains
unchanged. The rate of decrease of luminous intensity depends on the output of LEDs and
temperatures of LEDs. To prevent shortage of luminous intensity of LEDs one of the following
solutions shall be used:
• An alarm function shall be activated to notify the Officer of the Watch that the luminous
intensity of the light reduces below the level required by COLREGs; or
• LEDs shall only be used within the lifespan (practical term of validity) specified by the
manufacturer to maintain the necessary luminous intensity of LEDs. The lifespan of LEDs
should be determined and clearly notified by the manufacturer based on the appropriate
test results on the decrease of luminous intensity of the LEDs under various temperature
conditions and on the temperature condition of LEDs in the light during operation, taking
the appropriate margin into account.
NOTE The manufacturer of the navigation light should give information regarding detection of low illumination
intensity.
8 Steering gear
8.1 Power operated steering gear
8.1.1 Electric and/or electrohydraulic steering gear shall be used for the power-operated
main and auxiliary steering gear required by the appropriate authorities.
8.1.2 The electrical systems of the main steering gear and auxiliary steering gear shall be so
arranged that any failure in one of the steering gears will not render inoperative the electrical
systems of the other steering gear.
– 14 – 61892-5 © IEC:2010(E)
When an auxiliary steering gear is not required by the appropriate authorities and the main
steering gear comprises two or more power units, the electrical system for each power unit
shall be so arranged that the failure of one of them will not render the other units inoperative.
8.2 Motors
8.2.1 To determine the required characteristics of the electric motors for power units, the
breakaway torque and maximum working torque of the steering gear under all operating
conditions shall be used. The ratio of pull-out torque to rated torque shall be at least 1,6.
8.2.2 The rating shall be determined on the basis of the steering gear characteristics of the
subject unit as specified in 8.2.2.1 and 8.2.2.2.
NOTE Motors for steering gear power units may be rated for intermittent power demand.
8.2.2.1 For motors of electric steering gear power units the rating shall be as follows:
S3 – 40 % in accordance with lEC 60034-1.
8.2.2.2 For motors of electrohydraulic steering gear power units and for convertors, the
rating shall be as follows:
S6 – 25 % in accordance with IEC 60034-1.
8.3 Motor starters
Each electric motor of a main or auxiliary steering gear power unit shall be provided with its
own separate motor starter gear, either located within the steering gear compartment or in the
supply switchboard rooms (see 8.1.2).
8.4 Power circuits supply
8.4.1 Each electric or electrohydraulic steering gear comprising one or more power units
should, except as otherwise permitted by the appropriate authorities, be served by at least
two exclusive circuits, one fed directly from the main switchboard and one of the circuits shall
be supplied through the emergency switchboard.
NOTE 1 An auxiliary electric or electrohydraulic steering gear associated with a main electric or electrohydraulic
steering gear may be connected to one of the circuits supplying the main steering gear.
NOTE 2 The power supply system should be an IT system. For further information regarding IT systems, see
61892-2.
8.4.2 The circuits supplying an electric or electrohydraulic steering gear shall have a
continuous rating for supplying all electric motors and devices which can be simultaneously
connected to them and may be required to operate simultaneously.
8.4.3 For certain units specified by the appropriate authorities, an alternative power supply
from the emergency source of electrical power or from an independent source of power
located within the steering gear compartment, is required.
This power supply shall be activated automatically, within 45 s, in the event of power failure of
the main source(s) of electrical power and shall meet the requirements of the appropriate
authorities.
8.5 Supply of control circuits and control systems
8.5.1 Each control for starting and stopping of motors for power units shall be served by its
own control circuit supplied from its respective power circuit.
61892-5 © IEC:2010(E) – 15 –
8.5.2 Any electrical main and auxiliary steering gear control system shall be served by its
own separate circuit supplied from a steering gear power circuit from a point within the
steering gear compartment, or directly from switchboard busbars supplying that steering gear
power circuit at a point on the switchboard adjacent to the supply to the steering gear power
circuit.
8.6 Circuit protection
8.6.1 Short-circuit protection shall be provided for each control circuit and each power circuit
of electric or electrohydraulic main and auxiliary steering gear.
8.6.2 No protection other than short-circuit protection shall be provided for steering gear
control system supply circuits.
8.6.3 Protection against excess current, if provided for power circuits, shall be for not less
than twice the full load current of the motor or circuit so protected, and shall be arranged to
permit the passage of the appropriate starting currents.
8.7 Starting and stopping of motors for steering gear power units
8.7.1 Motors for power units shall be capable of being started and stopped from a position
on the navigating bridge and from a point within the steering gear compartment.
Means shall be provided at the position of the motor starters for isolating any remote
controlled starting and stopping devices.
8.7.2 Main and auxiliary steering gear power units shall be arranged to restart automatically
when power is restored after a power failure.
8.8 Steering gear control systems
8.8.1 For the main steering gear, control for the steering gear shall be provided both on the
navigating bridge and in the steering gear compartment.
8.8.2 For the power operated auxiliary steering gear, control for steering gear shall be
provided in the steering gear compartment and it shall also be operable from the navigating
bridge and shall be independent of the control system for the main steering gear.
8.8.3 When, in accordance with the appropriate authorities, an auxiliary steering gear is not
installed and the main steering gear comprises two or more identical power units, two
independent control systems shall be provided, both operable from the navigating bridge and
the steering gear compartment.
NOTE This does not require duplication of the steering wheel or steering lever.
Where the control system includes a hydraulic telemotor, a second independent control
system need not be fitted, except where specified by the appropriate authorities.
8.8.4 The steering gear control system provided in accordance with 8.8.1, 8.8.2 and 8.8.3
shall be capable of being brought into operation from a position on the navigating bridge.
8.8.5 Means shall be provided in the steering gear compartment for isolating any steering
gear control system operable from the navigating bridge from the steering gear it serves.
8.9 Alarms and indications
8.9.1 Means for indicating that the motors of electric and electrohydraulic steering gear are
running shall be installed on the navigating bridge and at a suitable main machinery control
position.
– 16 – 61892-5 © IEC:2010(E)
8.9.2 Overload alarms shall be provided for motors of power units for all main and auxiliary
steering gear.
8.9.3 Where a three-phase power supply is used, an alarm shall be provided that will
indicate failure of any one of the supply phases.
8.9.4 In the event of a power failure to any one of the steering gear power units, an alarm
shall be given.
8.9.5 In the event of a power failure of electrical power supply to the control system, an
alarm shall be given.
8.9.6 A low level alarm for each hydraulic fluid reservoir shall be provided to give the earliest
practicable indication of hydraulic fluid leakage.
8.9.7 The alarms specified in 8.9.2 to 8.9.6 shall
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