12.4.1 This sub-Section is applicable to mooring systems
incorporating winches, windlasses, etc., which are used to actively control and
adjust anchor line tensions in-service, or to release anchor lines in an
emergency.
12.4.2 Adequate controls are to be provided at the local control station for
satisfactory operation of the winch(es).
12.4.3 The braking system is to be arranged so that the brakes, when applied,
are not released in the event of a failure of the normal power supply.
12.4.4 Standby power is to be provided to enable winch brakes to be released
within 15 seconds in an emergency. The release arrangements are to be operable
locally at each winch and from the central control position, and are to be such that
the entire anchor line can be lowered in a controlled manner.
12.4.5 The standby power is to be such that during lowering of the anchor line it
is possible to apply the brakes once and then release them again in a controlled
manner.
12.4.6 Standby power is to be provided so that any anchor line
stoppers or pawl mechanisms may be released from either the local or central control
stations up to a line tension equal to the minimum rated break strength of the
anchor line. These mechanisms are to be capable of release at the maximum angles of
heel and trim under the damage stability and flooding conditions for which the unit
is designed.
12.4.7 At least one position reference system and one gyrocompass or equivalent
is to be provided, when applicable, to ensure the specified area of operation and
heading deviation can be effectively monitored.
12.4.8 Position reference systems are to incorporate suitable position
measurement techniques which may be by means of acoustic devices, radio, radar, taut
wire, riser angle, gangway extension and angle or other acceptable means, depending
on the service conditions for which the unit is intended.
12.4.9 A vertical reference sensor is to be provided, if applicable, to measure
the pitch and roll of the unit.
12.4.10 Means are to be provided to ascertain the wind speed and direction acting
on the unit.
12.4.11 The operation of winches, windlasses and associated brakes,
chain stoppers and pawls is to be controlled locally from weather protected control
stations which provide good visibility of the equipment and associated anchor
handling operations.
12.4.12 A central control station, which may be located on the
bridge or a separate manned control room, is to be provided from which brakes, chain
stoppers and pawls can be remotely released.
12.4.13 For each anchor winch the respective local control station is to be
provided with a means of indicating the following:
- Line tension.
- Length of line paid out.
- Line speed.
12.4.14 The indication required by 12.4.13(a), and (b), is to be repeated to the
central control station and in addition a means of indicating the following is to be
provided at this position:
- Mooring patterns and anchor line catenaries.
- Status of winch operation.
- ition and heading, see also 12.4.7.
- Gangway angle and extension, when applicable.
- Riser angle, when applicable.
- Wind speed and direction, see also 12.4.10.
12.4.15 Means of voice communication are to be provided between the central
control station, each local control station and anchor handling vessels, when
applicable.
12.4.16 Alarms are to be provided at the local and central control
stations for the following fault conditions:
- Excessive line tension.
- Loss of line tension.
- Excessive gangway angle and extension, when applicable.
- Excessive riser angle, when applicable.
12.4.17 Alarms are to be provided adjacent to the winches and windlasses to warn
personnel prior to and during any remote operation.
12.4.18 Alarms are to be provided at the central control station for the
following fault conditions:
- When the unit deviates from its predetermined area of
operation.
- When the unit deviates from its predetermined heading
limits.
These alarms are to be adjustable but should not exceed specified
limits. Arrangements are to be provided to fix and identify their set points.