A./Res.224(VII)
Performance standards for echo-sounding equipment
The Assembly,
Noting Article 16(i) of the Convention on the Inter-Governmental Maritime
Consultative Organization concerning the functions of the Assembly,
Bea
ring in mind Recommendation 36 relating to depth-sounding apparatus and
Recommendation 44, relating to electronic aids to navigation, adopted by the
International Conference on Safety of Life at Sea, 1960,
Having considered the Report of the Maritime Safety Committee on its
twenty-fourth session,
Endorses the Committee's Recommendation on performance standards for
echo-sounding equipment which will be required in accordance with the amended
Regulation 12 of Chapter V of the International Convention for the Safety of Life at
Sea, 1960,
Recommends Administrations to ensure that shipborne echo-sounding equipment
conforms to performance standards not inferior to those shown at Annex to this
Resolution.
01 Introduction
1.1 The echo-sounding equipment required by Regulation. 12
of Chapter V, as amended, should provide reliable information on the depth of water
under a ship to aid navigation.
1.2 The
equipment should comply with the following minimum performance requirements.
02 Range of depths
Under normal propagation conditions the equipment should be
capable of measuring any clearance under the transducer between 2 metres and 400
metres.
03 Range scales
3.1 The equipment should provide a minimum of two range
scales one of which, the deep range, should cover the whole range of depth, and the
other, the shallow range, one tenth thereof.
3.2 The scale of display should not be smaller than 2.5 mm per metre depth on
the shallow range scale and 0.25 mm per metre depth on the deep range scale.
04 Method of presentation
4.1 The primary presentation should be a graphical display
which provides the immediate depth and a visible record of soundings. Other forms of
display may be added but these should not affect the normal operation of the main
display.
4.2 The record should, on the deep
range scale, show at least 15 minutes of soundings.
4.3 Either by marks on the recording paper, or by other means, there should
be a clear indication when the paper remaining is approximately 10 percent of the length
of the roll.
05 Illumination
Fully adequate illumination should be provided to enable
identification of controls and facilitate reading of record and scales at all times.
Facilities for dimming should be provided.
06 Pulse repetition rate
The pulse repetition rate should be not slower than 12 pulses per
minute.
07 Accuracy of measurement
Based on a sound speed in water of 1500 metres per second, the
allowable tolerance on the indicated depth should be:
either
± 1 metre on the shallow range
scale
± 5 metres on the deep range scale
or
± 5 per cent of the indicated
depth, whichever is the greater.
08 Roll and pitch
The performance of the equipment should be such that it will meet
the requirements of the Recommendation when the ship is rolling ± 10°C and/or pitching ±
5°C.
09 Power supply
9.1 The equipment should be capable of operating in
accordance with the requirements of this Recommendation in the presence of such
variations of the power supply as are normally expected in a vessel.
9.2 Means should be incorporated for the protection of the
equipment from excessive currents and voltages, transients and accidental reversal of
power supply polarity.
9.3 If provision is
made for operating the equipment from more than one source of electrical energy,
arrangements for rapidly changing from one source of supply to the other should be
incorporated.
10 Interference
10.1 All reasonable and practicable steps should be taken
to eliminate the causes of, and to suppress, radio interference to other equipment on
board.
10.2 Mechanical noise from all units
should be so limited as not to prejudice the hearing of sound on which the safety of the
ship might depend.
10.3 Each unit of the
equipment should be marked with the minimum safe distances at which it may be mounted
from a standard or a steering magnetic compass.
11 Durability and resistance to effects of climate
The equipment should be capable of continuous operation under the
conditions of sea states, vibration, humidity and change of temperature likely to be
experienced in the vessel in which it is installed.
12 Miscellaneous
12.1
The equipment should be provided with an indication of manufacturer, type and/or
number.
12.2
- The equipment should be so constructed that it is readily accessible for
maintenance purposes.
- Information should be provided to enable competent members of a ship's staff to
operate and maintain the equipment efficiently.