8.1.2 Centralised
automated manual control of the thrusters is to be provided to supplement
the position mooring system. The manual control system is to provide
output signals to the thrusters, via the manual controller, to change
the speed, pitch and azimuth angle, as applicable, thereby optimising
line tension, as indicated at the central control station, see
Pt 7, Ch 8, 6.2 Control stations 6.2.4.
8.1.3 For assignment of notation (T2), the applicable requirements of Pt 7, Ch 8, 6 Electrical and control equipment and Pt 7, Ch 8, 7 Thruster-assisted positional mooring, together with Pt 7, Ch 8, 8.1 Notations 8.1.4 to Pt 7, Ch 8, 8.1 Notations 8.1.7 are to be complied with.
8.1.4 Automatic and manual control systems are to be provided to supplement the
positional mooring systems and arranged to operate independently, so that failure in one
system will not render the other system inoperative. See also
Pt 7, Ch 8, 8.1 Notations 8.1.2 for manual control.
8.1.5 The automatic control system is to utilise automatic input(s) from the
position reference system, the environmental sensors and line tensions, and
automatically provide output signals to the thrusters to change the speed, pitch and
azimuth angle, as applicable, thereby optimising line tension.
8.1.6 In the event of line failure or failure of the most effective thruster, the
ship is to be capable of maintaining its predetermined area of operation and desired
heading in the environmental conditions for which the ship is designed and/or
classed.
8.1.7 Control, alarm and safety systems are to incorporate a computer-based
consequence analysis, which may be continuous or at predetermined intervals, and is to
analyse the consequence of predetermined failures to verify that the anchor line
tensions and position/heading deviations remain within acceptable limits. In the event
of a possible hazardous condition arising as a result of the consequence analysis, an
alarm is to be initiated at the central control station.
8.1.8 For assignment of notation (T3), the applicable requirements of Pt 7, Ch 8, 6 Electrical and control equipment and Pt 7, Ch 8, 7 Thruster-assisted positional mooring, together with Pt 7, Ch 8, 8.1 Notations 8.1.5 to Pt 7, Ch 8, 8.1 Notations 8.1.7 and Pt 7, Ch 8, 8.1 Notations 8.1.9 to Pt 7, Ch 8, 8.1 Notations 8.1.12, are to be complied with.
8.1.9 Two automatic control systems are to be provided and arranged to operate
independently, so that failure in one system will not render the other system
inoperative.
8.1.10 In the event of failure of the working system, the standby automatic control
system is to be arranged to changeover automatically without manual intervention and
without any adverse effect on the ship's station keeping capability. The automatic
changeover is to initiate an alarm.