1
Introduction
1.1 In addition to the general requirements contained in resolution
A.694(17), automatic steering aids (automatic pilots) installed in craft operating under
the following conditions:
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.1 speed exceeding 30 knots and up to 70 knots;
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.2 maximum rate of turn 20°/s; and
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.3 normal range of operation between 70°N and 70°S
should, as required by chapter 13 of the HSC Code, comply with the minimum performance
requirements specified in these standards.
1.2 The automatic steering aid (automatic pilot) should, within a
speed range of up to 30 knots, comply with resolution A.342(IX), and within a speed
range of 30 knots to 70 knots should comply with the requirements of this
resolution.
2
General
2.1 Within limits related to the craft’s manoeuvrability, the
automatic steering aid, in conjunction with its source of heading information, should
enable a craft to keep within ±2.0° of a preset course.
2.2 The automatic steering aid equipment should be capable of manual
or automatic adjustment to different steering characteristics of the craft under various
weather and loading conditions.
2.3 The automatic steering aid should be connected to the
gyro-compass if a gyro-compass is provided. Otherwise it should be electronically
connected to the magnetic compass.
2.4 A qualitative description of the effects of the automatic
steering aid errors due to high speed, accelerations, course changes, sea state, etc.,
and a qualitative description of corresponding errors in other navigational aids, should
be provided to the user.
3
Change-Over from Automatic to Manual Steering and Vice Versa
3.1 Change-over from automatic to manual steering and vice versa
should be possible at any rudder position by means of a bumpless transfer.
3.2 Change-over from automatic to manual steering should be possible under any
conditions, including any failure in the automatic control system.
3.3 When changing over from manual to automatic steering, the automatic steering
aid (automatic pilot) should take over the actual heading as the preset course. Any
alteration of the preset course should not be possible without action by the craft’s
personnel.
3.4 Change-over controls should be located close to each other in the immediate
vicinity of the main steering or conning position.
3.5 Adequate indication should be provided to show which method of steering is in
operation at a particular moment.
3.6 The installation should include manual steering with an override
function.
4
Alarm Signalling Facilities
4.1 Alarm signals, both audible and visual to the navigator on watch,
should be provided in order to indicate failure or a reduction in the power supply to
the automatic steering aid, which would affect the safe operation of the equipment.
4.2 A course monitor should be provided which operates a clearly
audible ‘‘off-course’’ alarm signal after a course deviation of a preset amount from the
ordered course.
4.3 The information required to actuate the course monitor should be
provided from an independent source.
4.4 The automatic steering aid should provide an indication when any
input from an external sensor is absent. The automatic steering aid should also repeat
any alarm or status warnings concerning the quality of the input data from its external
sensors which may influence its operation.
4.5 The alarm signal facilities should be fitted near the steering or
conning position.
5
Controls
5.1 The automatic steering aid should be provided with automatic and
manually operated controls for operational use to adjust the craft’s steering
performance to take account of the effects of weather.
5.2 The sense of the control of the automatic steering aid should be
such as to ensure altering course to starboard by turning the course setting control
clockwise. If the control is digital then provision should also be made for keying in
the required turn sense. Normal alterations of course should be possible by one
adjustment only of the course setting control.
5.3 Except for the course setting control, the actuation of any other
control should not significantly affect the course of the craft.
5.4 Additional controls at remote positions should comply with the
provisions of these performance standards.
5.5 The automatic steering aid should be able to perform turns within
the turning capability of the craft based either on a preset turning radius or a preset
rate of turn.
6
Rudder Angle Limitation
Means should be incorporated in the equipment to enable rudder angle
limitation in the automatic mode of operation. Means should also be available to
indicate when the angle of limitation has been reached.
7
Permitted Yaw
Means should be incorporated to prevent unnecessary activation of the
rudder due to normal yaw motion.
8
Interface
The automatic steering aid should provide interface facilities conforming to relevant
international marine interface standards.footnote