1 The number of openings in watertight bulkheads
shall be reduced to the minimum compatible with the design and proper
working of the ship, satisfactory means shall be provided for closing
these openings.
2.1 Where pipes, scuppers, electric cables, etc.,
are carried through watertight bulkheads, arrangements shall be made
to ensure the watertight integrity of the bulkheads.
2.2 Valves not forming part of a piping system
shall not be permitted in watertight bulkheads.
2.3 Lead or other heat sensitive materials shall
not be used in systems which penetrate watertight bulkheads, where
deterioration of such systems in the event of fire would impair the
watertight integrity of the bulkheads.
3 No doors, manholes, or access openings are permitted
in watertight transverse bulkheads dividing a cargo space from an
adjoining cargo space, except as provided in paragraph 9.1 and in regulation 14.
4 Subject to paragraph 10, not more than one door,
apart from the doors to shaft tunnels, may be fitted in each watertight
bulkhead within spaces containing the main and auxiliary propulsion
machinery including boilers serving the needs of propulsion. Where
two or more shafts are fitted, the tunnels shall be connected by an
intercommunicating passage. There shall be only one door between the
machinery space and the tunnel spaces where two shafts are fitted
and only two doors where there are more than two shafts. All these
doors shall be of the sliding type and shall be so located as to have
their sills as high as practicable. The hand gear for operating these
doors from above the bulkhead deck shall be situated outside the spaces
containing the machinery.
5.1 Watertight doors, except as provided in paragraph
9.1 or regulation 14, shall
be power-operated sliding doors complying with the requirements of
paragraph 7 capable of being closed simultaneously from the central
operating console at the navigation bridge in not more than 60 s with
the ship in the upright position.
5.2 The means of operation whether by power or
by hand of any power-operated sliding watertight door shall be capable
of closing the door with the ship listed to 15° either way. Consideration
shall also be given to the forces which may act on either side of
the door as may be experienced when water is flowing through the opening,
applying a static head equivalent to a water height of at least 1
m above the sill on the centreline of the door.
5.3 Watertight door controls, including hydraulic
piping and electric cables, shall be kept as close as practicable
to the bulkhead in which the doors are fitted, in order to minimize
the likelihood of them being involved in any damage which the ship
may sustain. The positioning of watertight doors and their controls
shall be such that if the ship sustains damage within one fifth of
the breadth of the ship, as defined in regulation
2, such distance being measured at right angles to the centreline
at the level of the deepest subdivision draught, the operation of
the watertight doors clear of the damaged portion of the ship is not
impaired.
6 All power-operated sliding watertight doors
shall be provided with means of indication which will show at all
remote operating positions whether the doors are open or closed. Remote
operating positions shall only be at the navigation bridge as required
by paragraph 7.1.5 and at the location where hand operation above
the bulkhead deck is required by paragraph 7.1.4.
7.1 Each power-operated sliding watertight door:
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.1 shall have a vertical or horizontal motion;
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.2 shall, subject to paragraph 10, be normally
limited to a maximum clear opening width of 1.2 m. The Administration
may permit larger doors only to the extent considered necessary for
the effective operation of the ship provided that other safety measures,
including the following, are taken into consideration:
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.3 shall be fitted with the necessary equipment
to open and close the door using electric power, hydraulic power,
or any other form of power that is acceptable to the Administration;
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.4 shall be provided with an individual hand-operated
mechanism. It shall be possible to open and close the door by hand
at the door itself from either side, and in addition, close the door
from an accessible position above the bulkhead deck with an all round
crank motion or some other movement providing the same degree of safety
acceptable to the Administration. Direction of rotation or other movement
is to be clearly indicated at all operating positions. The time necessary
for the complete closure of the door, when operating by hand gear,
shall not exceed 90 s with the ship in the upright position;
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.5 shall be provided with controls for opening
and closing the door by power from both sides of the door and also
for closing the door by power from the central operating console at
the navigation bridge;
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.6 shall be provided with an audible alarm, distinct
from any other alarm in the area, which will sound whenever the door
is closed remotely by power and which shall sound for at least 5 s
but no more than 10 s before the door begins to move and shall continue
sounding until the door is completely closed. In the case of remote
hand operation it is sufficient for the audible alarm to sound only
when the door is moving. Additionally, in passenger areas and areas
of high ambient noise the Administration may require the audible alarm
to be supplemented by an intermittent visual signal at the door; and
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.7 shall have an approximately uniform rate of
closure under power. The closure time, from the time the door begins
to move to the time it reaches the completely closed position, shall
in no case be less than 20 s or more than 40 s with the ship in the
upright position.
7.2 The electrical power required for power-operated
sliding watertight doors shall be supplied from the emergency switchboard
either directly or by a dedicated distribution board situated above
the bulkhead deck. The associated control, indication and alarm circuits
shall be supplied from the emergency switchboard either directly or
by a dedicated distribution board situated above the bulkhead deck
and be capable of being automatically supplied by the transitional
source of emergency electrical power required by regulation 42.3.1.3 in the event of
failure of either the main or emergency source of electrical power.
7.3 Power-operated sliding watertight doors shall
have either:
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.1 a centralized hydraulic system with two independent
power sources each consisting of a motor and pump capable of simultaneously
closing all doors. In addition, there shall be for the whole installation
hydraulic accumulators of sufficient capacity to operate all the doors
at least three times, i.e. closed-open-closed, against an adverse
list of 15º. This operating cycle shall be capable of being carried
out when the accumulator is at the pump cut-in pressure. The fluid
used shall be chosen considering the temperatures liable to be encountered
by the installation during its service. The power operating system
shall be designed to minimize the possibility of having a single failure
in the hydraulic piping adversely affect the operation of more than
one door. The hydraulic system shall be provided with a low-level
alarm for hydraulic fluid reservoirs serving the power-operated system
and a low gas pressure alarm or other effective means of monitoring
loss of stored energy in hydraulic accumulators. These alarms are
to be audible and visual and shall be situated on the central operating
console at the navigation bridge; or
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.2 an independent hydraulic system for each door
with each power source consisting of a motor and pump capable of opening
and closing the door. In addition, there shall be a hydraulic accumulator
of sufficient capacity to operate the door at least three times, i.e.
closed-open-closed, against an adverse list of 15º. This operating
cycle shall be capable of being carried out when the accumulator is
at the pump cut-in pressure. The fluid used shall be chosen considering
the temperatures liable to be encountered by the installation during
its service. A low gas pressure group alarm or other effective means
of monitoring loss of stored energy in hydraulic accumulators shall
be provided at the central operating console on the navigation bridge.
Loss of stored energy indication at each local operating position
shall also be provided; or
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.3 an independent electrical system and motor
for each door with each power source consisting of a motor capable
of opening and closing the door. The power source shall be capable
of being automatically supplied by the transitional source of emergency
electrical power as required by regulation
42.4.2 – in the event of failure of either the main or
emergency source of electrical power and with sufficient capacity
to operate the door at least three times, i.e. closed-open-closed,
against an adverse list of 15º.
For the systems specified in paragraphs 7.3.1, 7.3.2 and 7.3.3,
provision should be made as follows: Power systems for power-operated
watertight sliding doors shall be separate from any other power system.
A single failure in the electric or hydraulic power-operated systems
excluding the hydraulic actuator shall not prevent the hand operation
of any door.
7.4 Control handles shall be provided at each
side of the bulkhead at a minimum height of 1.6 m above the floor
and shall be so arranged as to enable persons passing through the
doorway to hold both handles in the open position without being able
to set the power closing mechanism in operation accidentally. The
direction of movement of the handles in opening and closing the door
shall be in the direction of door movement and shall be clearly indicated.
7.5 As far as practicable, electrical equipment
and components for watertight doors shall be situated above the bulkhead
deck and outside hazardous areas and spaces.
7.6 The enclosures of electrical components necessarily
situated below the bulkhead deck shall provide suitable protection
against the ingress of water.footnote
7.7 Electric power, control, indication and alarm
circuits shall 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 shall not result in a loss of power operation of that door.
Arrangements shall be such that leakage of water into the electrical
equipment located below the bulkhead deck will not cause the door
to open.
7.8 A single electrical failure in the power operating
or control system of a power-operated sliding watertight door shall
not result in a closed door opening. Availability of the power supply
should be continuously monitored at a point in the electrical circuit
as near as practicable to each of the motors required by paragraph
7.3. Loss of any such power supply should activate an audible and
visual alarm at the central operating console at the navigation bridge.
8.1 The central operating console at the navigation
bridge shall have a "master mode" switch with two modes of control:
a "local control" mode which shall allow any door to be locally opened
and locally closed after use without automatic closure, and a "doors
closed" mode which shall automatically close any door that is open.
The "doors closed" mode shall automatically close any door that is
open. The "doors closed" mode shall permit doors to be opened locally
and shall automatically re-close the doors upon release of the local
control mechanism. The "master mode" switch shall normally be in the
"local control" mode. The "doors closed" mode shall only be used in
an emergency or for testing purposes. Special consideration shall
be given to the reliability of the "master mode" switch.
8.2 The central operating console at the navigation
bridge shall 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 shall indicate a door is fully open and a green
light shall indicate a door is fully closed. When the door is closed
remotely the red light shall indicate the intermediate position by
flashing. The indicating circuit shall be independent of the control
circuit for each door.
8.3 It shall not be possible to remotely open
any door from the central operating console.
9.1 If the Administration is satisfied that such
doors are essential, watertight doors of satisfactory construction
may be fitted in watertight bulkheads dividing cargo between deck
spaces. Such doors may be hinged, rolling or sliding doors but shall
not be remotely controlled. They shall be fitted at the highest level
and as far from the shell plating as practicable, but in no case shall
the outboard vertical edges be situated at a distance from the shell
plating which is less than one fifth of the breadth of the ship, as
defined in regulation 2, such
distance being measured at right angles to the centreline at the level
of the deepest subdivision draught.
9.2 Should any such doors be accessible during
the voyage, they shall be fitted with a device which prevents unauthorized
opening. When it is proposed to fit such doors, the number and arrangements
shall receive the special consideration of the Administration.
10 Portable plates on bulkheads shall not be permitted
except in machinery spaces. The Administration may permit not more
than one power-operated sliding watertight door in each watertight
bulkhead larger than those specified in paragraph 7.1.2 to be substituted
for these portable plates, provided these doors are intended to remain
closed during navigation except in case of urgent necessity at the
discretion of the master. These doors need not meet the requirements
of paragraph 7.1.4 regarding complete closure by hand-operated gear
in 90 s.
11.1 Where trunkways or tunnels for access from crew
accommodation to the machinery spaces, for piping, or for any other purpose are carried
through watertight bulkheads, they shall be watertight and in accordance with the
requirements of regulation 16-1. The access to at least one end of each such tunnel or
trunkway, if used as a passage at sea, shall be through a trunk extending watertight to
a height sufficient to permit access above the bulkhead deck. The access to the other
end of the trunkway or tunnel may be through a watertight door of the type required by
its location in the ship. Such trunkways or tunnels shall not extend through the first
subdivision bulkhead abaft the collision bulkhead.
11.2 Where it is proposed to fit tunnels piercing
watertight bulkheads, these shall receive the special consideration
of the Administration.
11.3 Where trunkways in connection with refrigerated
cargo and ventilation or forced draught trunks are carried through
more than one watertight bulkhead, the means of closure at such openings
shall be operated by power and be capable of being closed from a central
position situated above the bulkhead deck.