Section
14 Water ingress detection arrangements
14.1 General requirements
14.1.6
Pt 6, Ch 1, 1.4 Control, alarm and safety equipment 1.4.1 details applicable
requirements for Survey at the manufacturer’s works. At the
initial installation and during each subsequent Complete Survey of
Machinery alarm systems or Special Survey, the operation of the ingress
detection arrangements is to be demonstrated to the satisfaction of
the LR Surveyor.
14.1.7 Where
alternative arrangements to those required by Pt 5, Ch 13, 14.1 General requirements 14.1.2 to Pt 5, Ch 13, 14.1 General requirements 14.1.4 are proposed, evidence
is to be submitted for consideration by LR that demonstrates:
- water ingress will be detected in all areas considered necessary
to reliably detect flooding of watertight spaces;
- responsible personnel will be effectively notified in the event
of water ingress to allow for planned response; and
- acceptance by the National Administration with which the ship
is registered.
14.2 Water ingress detection arrangements in bulk carriers
14.2.1 Bulk
carriers are to be fitted with water level detectors:
-
in each cargo
hold, giving audible and visual alarms, one when the water level above
the inner bottom in any hold reaches a height of 0,5 m and another
at a height not less than 15 per cent of the depth of the cargo hold
but not more than 2 m. The water level detectors are to be fitted
in the aft end of each cargo hold. For cargo holds which are used
for water ballast, an alarm overriding device may be installed. The
visual alarms are to clearly discriminate between the two different
water levels detected in each hold;
-
in any ballast
tank forward of the collision bulkhead required by Pt 3, Ch 3, 4 Bulkhead requirements, giving an audible and
visual alarm when the liquid in the tank reaches a level not exceeding
10 per cent of the tank capacity. An alarm overriding device may be
installed to be activated when the tank is in use; and
-
in any dry or
void space other than a chain cable locker, any part of which extends
forward of the foremost cargo hold, giving an audible and visual alarm
at a water level of 0,1 m above the deck. Such alarms need not be
provided in enclosed spaces the volume of which does not exceed 0,1
per cent of the ship's maximum displacement volume.
14.3 Water ingress detection arrangements in single hold cargo ships
14.3.1 Ships
having a length, L, of less than 80 m and a single cargo
hold below the freeboard deck or cargo holds below the freeboard deck
which are not separated by at least one bulkhead made watertight up
to that deck, are to be fitted in such space or spaces with water
level detectors.
14.3.2 The
water level detectors required by Pt 5, Ch 13, 14.3 Water ingress detection arrangements in single hold cargo ships 14.3.1 are to:
-
give an audible
and visual alarm when the water level above the inner bottom in the
cargo hold reaches a height of not less than 0,3 m, and another when
such level reaches not more than 15 per cent of the mean depth of
the cargo hold; and
-
be fitted at
the aft end of the hold, or above its lowest part where the inner
bottom is not parallel to the designed waterline. Where webs or partial
watertight bulkheads are fitted above the inner bottom, the installation
of additional detectors is to be considered.
14.4 Flooding detection systems in passenger ships
14.4.1 Passenger
ships for 36 persons or more are to be provided with a flooding detection
system for watertight spaces below the bulkhead deck.
14.4.2 The
flooding detection system required by Pt 5, Ch 13, 14.4 Flooding detection systems in passenger ships 14.4.1 is to be fitted in all watertight spaces below the bulkhead
deck that:
-
have a volume,
in cubic metres, that is more than the ship’s moulded displacement
per centimetre immersion at deepest subdivision draught; or
-
have a volume
more than 30 cubic metres, whichever is the greater.
14.4.3 Any
watertight spaces that are individually equipped with a liquid level
monitoring system (such as fresh water, ballast water, fuel, etc.),
including an indicator panel or other means of monitoring at the navigation
bridge, and the safety centre if located in a separate space from
the navigation bridge, are excluded from the requirements of this
sub-Section.
14.4.4 The
number and location of flooding detection sensors is to be sufficient
to ensure that any substantial water ingress into a watertight space
requiring a flooding detection system is detected under reasonable
angles of trim and heel. To accomplish this, flooding detection sensors
are to be installed as indicated below:
-
Vertical
location – sensors are to be installed as low as practical
in the watertight space;
-
Longitudinal
location – in watertight spaces located forward of the
mid-length sensors are generally to be installed at the forward end
of the space; and in watertight spaces located aft of the mid-length,
sensors are generally to be installed at the aft end of the space.
For watertight spaces located in the vicinity of the midlength, consideration
is to be given to the appropriate longitudinal location of the sensor.
In addition, any watertight space of length more than 20 per cent
of the ship’s subdivision length or with arrangements that would
seriously restrict the longitudinal flow of water is to be provided
with sensors at both the forward and aft ends; and
-
Transverse
location – sensors are generally to be installed at the
centreline of the space (or alternatively at both the port and starboard
sides). In addition, any watertight space that extends the full breadth
of the ship or with arrangements that would seriously restrict the
transverse flow of water is to be provided with sensors at both the
port and starboard sides.
14.4.5 Where
a watertight space extends in height over more than one deck, there
is to be at least one flooding detection sensor at each deck level.
This provision is not applicable in cases where a continuous flood
level monitoring system is installed.
14.4.6 Consideration
may be given to the number and location of flooding detection sensors
in watertight spaces with unusual arrangements or in other cases where
these requirements would not achieve the intended purpose, see
Pt 5, Ch 13, 14.1 General requirements 14.1.7.
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