1 INTRODUCTIONThe ship earth station installation capable of
telephony and data communications should comply with the general requirements set out
in resolution A.694(17) and with the following minimum requirements.
2 TECHNICAL REQUIREMENTSThe equipment should be type approved by Inmarsat
and should comply with the environmental conditions specified in its technical
requirements for Inmarsat ship earth stations capable of two-way communications.
3 OPERATION3.1 No control external to the equipment
should be available for alteration of the ship station identity.
3.2 It should be possible to initiate and make distress calls
by telephony or data communications from the position at which the ship is normally
navigated and from any other position designated for distress alerting. In addition,
where a room is provided for radiocommunications, means to initiate distress calls
should also be fitted in that room.
3.3
Where no other means of receiving distress, urgency and safety broadcasts or an
addressed distress alert relay are provided and existing levels of aural signals
produced by the telephone or printer are considered to be inadequate, the ship earth
station equipment should provide an aural/visual alarm of appropriate level.
3.4 It should be possible to interrupt or
initiate distress calls at any time.
3.5 A
distress call should be activated only by means of a dedicated distress button. This
button should not be any key of an ITU-T digital input panel or an ISO keyboard
provided on the equipment.
3.6 The
dedicated distress button should*:
- .1 be clearly identified; and
- .2 be protected against inadvertent operation. 3.7 The distress call initiation should
require at least two independent actions. 3.8 Paragraphs 3.5, 3.6 and 3.7 do not apply to Inmarsat-A ship earth
stations. 4 RADIO FREQUENCY HAZARDS In
order to permit warning of potential radiation hazards to be displayed in
appropriate places, a label should be attached to the radome indicating the
distance at which radiation levels of 100 W/m2, 25 W/m2 and 10 W/m2 exist. 5 POWER SUPPLY5.1 The ship earth station should
normally be powered from the ship’s main source of electrical energy. In addition,
it should be possible to operate the ship earth station and all equipment
necessary for its normal functioning, including the antenna tracking system, from
an alternative source of energy. 5.2
Changing from one source of supply to another or any interruption up to 60 s of
the supply of electrical energy should not render the equipment inoperative or
require the equipment to be re-initialized. 6 ANTENNA SITING6.1 It is desirable that the antenna be
sited in such a position that no obstacles likely significantly to degrade the
performance of the equipment appear in any azimuth down to an angle of elevation
of -5º. 6.2 The sitting of the antenna
needs careful consideration, taking into account the adverse effect of high levels
of vibration which might be introduced by the use of a tall mast and the need to
minimize shadow sectors. Objects, especially those within 10 m of the radome which
cause a shadow sector of greater than 6º, are likely significantly to degrade the
performance of the equipment. 6.3 The
above-deck equipment should be separated, as far as is practicable, from the
antennae of other communication and navigation equipment. * MSC/Circ.862 . Clarifications of certain requirements in
IMO performance standards for GMDSS equipment.