Onderwerp: Bezoek-historie

524(13) Performance standards for VHF multiple watch facilities
Geldigheid:17-11-1983 t/m 31-12-2023Status: Was geldig

Dit onderwerp bevat de volgende rubrieken.


RECALLING Article 16(j) of the Convention on the International Maritime Organization concerning the functions of the Assembly in relation to regulations concerning maritime safety,

BEARING IN MIND the provisions of regulation 3, chapter IV of the International Convention for the Safety of Life at Sea, 1974, as amended in 1981,

HAVING CONSIDERED the recommendation made by the Maritime Safety Committee at its forty-eighth session,

1. ADOPTS the Recommendation on Performance Standards for VHS Multiple Watch Facilities set out in the Annex to the present resolution;

2. RECOMMENDS Governments to ensure that shipborne equipment fitted with VHF multiple watch facilities conforms to performance standards not inferior to those specified in the Annex to the present resolution.*
* Some Administrations do not consider that the scanning facility will satisfy their national VHF watch requirements when a ship is participating in a system operating pursuant to regulation 18 of chapter V of the 1974 SOLAS Convention.

Annex Performance standards for VHF multiple watch facilities


VHF radiotelephone equipment having multiple watch facilities should, in addition to meeting the applicable operational standards for VHF radiotelephone installations, comply with the following performance standards.


2.1 The equipment should include a provision for the automatic scanning of a priority channel and one additional channel only.

2.2 The priority channel is that channel which will be sampled even if there is a signal on the additional channel and on which the receiver will lock during the time a signal is detected.

2.3 The additional channel is that channel which will be monitored during the periods the equipment is not sampling or receiving signals on the priority channel.

2.4 Provision should be included to switch the scanning facility on and off by means of a manually operated control. In addition it should be ensured that the receiver remains on the same channel as the transmitter for the entire duration of any communication with the ship, e.g. the scanning facility could be switched off automatically when the handset is off its hook.

2.5 Selection of the additional channel and, if provided, of the priority channel should be possible at the operating position of the receiver or transceiver. If selection of the priority channel is not provided, the priority channel should be channel 16 unless an Administration considers that an alternative channel should be watched in a particular area.

2.6 When the scanning facility is in operation, the channel number of both channels on which the equipment is operating should be clearly indicated simultaneously.

2.7 In a transceiver, transmission should not be possible when the scanning facility is operating. When the scanning facility is switched off, both transmitter and receiver should be tuned automatically to the selected additional channel.

2.8 A transceiver should be provided with a single manual control (e.g. push-button) in order to switch the equipment quickly for operation on the priority channel.

2.9 At the operating position of a transceiver the selected additional channel should be clearly indicated as being the operational channel of this receiver.


3.1 When the scanning facility is switched on, the priority channel should be sampled with a sampling frequency of not less than once per 2 seconds. If a signal is detected on the priority channel the receiver should remain on this channel for the duration of that signal.

3.2 If a signal is detected on the additional channel the sampling of the priority channel should continue, thus interrupting the reception on the additional channel for periods as short as possible and not greater than 150 milliseconds. The design of the receiver should provide for its proper functioning during the period the priority channel is sampled since the receiving conditions on the priority channel may differ from those on the additional channel.

3.3 In the absence of a signal on the priority channel and during reception of a signal on the additional channel, the duration of each listening period on this channel should be at least 850 milliseconds.

3.4 Means should be provided to indicate the channel on which a signal is being received.
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