19.1.2 A single
failure in the power operating or control system of power-operated
sliding watertight doors is not to result in a closed door opening
or prevent the hand operation of any door.
19.1.3 Availability
of the power supply is to be continuously monitored at a point in
the electrical circuit adjacent to the door operating equipment. Loss
of any such power supply is to activate an audible and visual alarm
at the central operating console at the navigating bridge.
19.1.4 Electrical
power, control, indication and alarm circuits are to be protected
against fault in such a way that a failure in one door circuit will
not cause a failure in any other door circuit. Short circuits or other
faults in the alarm or indicator circuits of a door are not to result
in a loss of power operation of the door. Arrangements are to be such
that leakage of water into the electrical equipment located below
the bulkhead deck will not cause the door to open.
19.1.5 The
enclosures of electrical components necessarily situated below the
waterline in the final condition of damage or below the bulkhead deck
as applicable are to provide suitable protection against the ingress
of water with ratings as defined in IEC 60529: Degrees of protection
provided by enclosures (IP Code) or an acceptable and relevant
National Standard, as follows:
-
Electrical motors,
associated circuits and control components, protected to IPX7 Standard.
-
Door position indicators
and associated circuit components protected to IPX8 Standard, where
the water pressure testing of the enclosures is to be based on the
pressure that may occur at the location of the component during flooding
for a period of 36 hours.
-
Door movement warning
signals, protected to IPX6 Standard.
19.1.6 Watertight
door electrical controls including their electric cables are to be
kept as close as is practicable to the bulkhead in which the doors
are fitted and so arranged that the likelihood of them being involved
in any damage which the craft may sustain is minimised.
19.1.7 An audible
alarm, distinct from any other alarm in the area, is to sound whenever
the door is closed remotely by power and sound for at least five seconds
but no more than ten seconds before the door begins to move and is
to continue sounding until the door is completely closed. The audible
alarm is to be supplemented by an intermittent visual signal at the
door in passenger areas and areas where the noise level exceeds 85
dB(A).
19.1.8 A central
operating console is to be fitted on the navigating bridge and is
to be provided with a `master-mode' switch having:
-
a `local control'
mode for normal use which is to allow any door to be locally opened
and locally closed after use without automatic closure, and;
-
a `doors closed'
mode for emergency use which is to allow any door that is opened to
be automatically closed whilst still permitting any doors to be locally
opened but with automatic reclosure upon release of the local control
mechanism.
19.1.9 The
`master mode' switch is to be arranged to be normally in the `local
control' mode position; be clearly marked as to its emergency function
and be Type Approved in accordance with LR's Procedure for Type Approved
Products.
19.1.10 The
central operating console at the navigating bridge is to be provided
with a diagram showing the location of each door, with visual indicators
to show whether each door is open or closed. A red light is to indicate
a door is fully open and a green light, a door fully closed. When
the door is closed remotely a red light is to indicate the intermediate
position by flashing. The indicating circuit is to be independent
of the control circuit for each door.
19.1.11 The
arrangements are to be such that it is not possible to remotely open
any door from the central operating console.