Goal
To ensure that the cargo containment and handling system are located such that
the consequences of any release of cargo will be minimized, and to provide safe
access for operation and inspection.
3.1
Segregation of the cargo area
3.1.1 Hold spaces shall be segregated from machinery
and boiler spaces, accommodation spaces, service spaces, control stations, chain
lockers, domestic water tanks and from stores. Hold spaces shall be located forward
of machinery spaces of category A. Alternative arrangements, including locating
machinery spaces of category A forward, may be accepted, based on SOLAS regulation
II-2/17, after further consideration of involved risks, including that of cargo
release and the means of mitigation.
3.1.2 Where cargo is carried in a cargo containment
system not requiring a complete or partial secondary barrier, segregation of hold
spaces from spaces referred to in 3.1.1 or spaces either below or outboard of the
hold spaces may be effected by cofferdams, oil fuel tanks or a single gastight
bulkhead of all-welded construction forming an "A-60" class division. A gastight
"A-0" class division is acceptable if there is no source of ignition or fire hazard
in the adjoining spaces.
3.1.3 Where cargo is carried in a cargo containment
system requiring a complete or partial secondary barrier, segregation of hold spaces
from spaces referred to in 3.1.1, or spaces either below or outboard of the hold
spaces that contain a source of ignition or fire hazard, shall be effected by
cofferdams or oil fuel tanks. A gastight "A-0" class division is acceptable if there
is no source of ignition or fire hazard in the adjoining spaces.
3.1.4 Turret compartments segregation from spaces
referred to in 3.1.1, or spaces either below or outboard of the turret compartment
that contain a source of ignition or fire hazard, shall be effected by cofferdams or
an A-60 class division. A gastight "A-0" class division is acceptable if there is no
source of ignition or fire hazard in the adjoining spaces.
3.1.5 In addition, the risk of fire propagation from
turret compartments to adjacent spaces shall be evaluated by a risk analysis (see
1.1.11) and further preventive measures, such as the arrangement of a cofferdam
around the turret compartment, shall be provided if needed.
3.1.6 When cargo is carried in a cargo containment
system requiring a complete or partial secondary barrier:
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.1 at temperatures below -10°C, hold spaces
shall be segregated from the sea by a double bottom; and
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.2 at temperatures below -55°C, the ship shall
also have a longitudinal bulkhead forming side tanks.
3.1.7 Arrangements shall be made for sealing the
weather decks in way of openings for cargo containment systems.
3.2
Accommodation, service and machinery spaces and control stations
3.2.1 No accommodation space, service space or control
station shall be located within the cargo area. The bulkhead of accommodation
spaces, service spaces or control stations that face the cargo area shall be so
located as to avoid the entry of gas from the hold space to such spaces through a
single failure of a deck or bulkhead on a ship having a containment system requiring
a secondary barrier.
3.2.2 To guard against the danger of hazardous vapours,
due consideration shall be given to the location of air intakes/outlets and openings
into accommodation, service and machinery spaces and control stations in relation to
cargo piping, cargo vent systems and machinery space exhausts from gas burning
arrangements.
3.2.3 Access through doors, gastight or otherwise,
shall not be permitted from a non-hazardous area to a hazardous area except for
access to service spaces forward of the cargo area through airlocks, as permitted by
3.6.1, when accommodation spaces are aft.
3.2.4.1 Entrances, air inlets and openings to
accommodation spaces, service spaces, machinery spaces and control stations shall
not face the cargo area. They shall be located on the end bulkhead not facing the
cargo area or on the outboard side of the superstructure or deckhouse or on both at
a distance of at least 4% of the length (L) of the ship but not less than 3 m
from the end of the superstructure or deckhouse facing the cargo area. This
distance, however, need not exceed 5 m.
3.2.4.2 Windows and sidescuttles facing the cargo area
and on the sides of the superstructures or deckhouses within the distance mentioned
above shall be of the fixed (non-opening) type. Wheelhouse windows may be non-fixed
and wheelhouse doors may be located within the above limits so long as they are
designed in a manner that a rapid and efficient gas and vapour tightening of the
wheelhouse can be ensured.
3.2.4.3 For ships dedicated to the carriage of cargoes
that have neither flammable nor toxic hazards, the Administration may approve
relaxations from the above requirements.
3.2.4.4 Accesses to forecastle spaces containing
sources of ignition may be permitted through a single door facing the cargo area,
provided the doors are located outside hazardous areas as defined in chapter 10.
3.2.5 Windows and sidescuttles facing the cargo area
and on the sides of the superstructures and deckhouses within the limits specified
in 3.2.4, except wheelhouse windows, shall be constructed to "A-60" class.
Sidescuttles in the shell below the uppermost continuous deck and in the first tier
of the superstructure or deckhouse shall be of fixed (non-opening) type.
3.2.6 All air intakes, outlets and other openings into
the accommodation spaces, service spaces and control stations shall be fitted with
closing devices. When carrying toxic products, they shall be capable of being
operated from inside the space. The requirement for fitting air intakes and openings
with closing devices operated from inside the space for toxic products need not
apply to spaces not normally manned, such as deck stores, forecastle stores,
workshops. In addition, the requirement does not apply to cargo control rooms
located within the cargo area.
3.2.7 Control rooms and machinery spaces of turret
systems may be located in the cargo area forward or aft of cargo tanks in ships with
such installations. Access to such spaces containing sources of ignition may be
permitted through doors facing the cargo area, provided the doors are located
outside hazardous areas or access is through airlocks.
3.3 Cargo machinery spaces and turret
compartments
3.3.1 Cargo machinery spaces shall be situated above
the weather deck and located within the cargo area. Cargo machinery spaces and
turret compartments shall be treated as cargo pump-rooms for the purpose of fire
protection according to SOLAS regulation II-2/9.2.4, and for the purpose of prevention of potential
explosion according to SOLAS regulation ll-2/4.5.10.
3.3.2 When cargo machinery spaces are located at the
after end of the aftermost hold space or at the forward end of the foremost hold
space, the limits of the cargo area, as defined in 1.2.7, shall be extended to
include the cargo machinery spaces for the full breadth and depth of the ship and
the deck areas above those spaces.
3.3.3 Where the limits of the cargo area are extended
by 3.3.2, the bulkhead that separates the cargo machinery spaces from accommodation
and service spaces, control stations and machinery spaces of category A shall be
located so as to avoid the entry of gas to these spaces through a single failure of
a deck or bulkhead.
3.3.4 Cargo compressors and cargo pumps may be driven
by electric motors in an adjacent non-hazardous space separated by a bulkhead or
deck, if the seal around the bulkhead penetration ensures effective gastight
segregation of the two spaces. Alternatively, such equipment may be driven by
certified safe electric motors adjacent to them if the electrical installation
complies with the requirements of chapter 10.
3.3.5 Arrangements of cargo machinery spaces and turret
compartments shall ensure safe unrestricted access for personnel wearing protective
clothing and breathing apparatus, and in the event of injury to allow unconscious
personnel to be removed. At least two widely separated escape routes and doors shall
be provided in cargo machinery spaces, except that a single escape route may be
accepted where the maximum travel distance to the door is 5 m or less.
3.3.6 All valves necessary for cargo handling shall be
readily accessible to personnel wearing protective clothing. Suitable arrangements
shall be made to deal with drainage of pump and compressor rooms.
3.3.7 Turret compartments shall be designed to retain
their structural integrity in case of explosion or uncontrolled high-pressure gas
release (overpressure and/or brittle fracture), the characteristics of which shall
be substantiated on the basis of a risk analysis with due consideration of the
capabilities of the pressure relieving devices.
3.4 Cargo control rooms
3.4.1 Any cargo control room shall be above the weather
deck and may be located in the cargo area. The cargo control room may be located
within the accommodation spaces, service spaces or control stations, provided the
following conditions are complied with:
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.1 the cargo control room is a non-hazardous
area;
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.2 if the entrance complies with 3.2.4.1, the
control room may have access to the spaces described above; and
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.3 if the entrance does not comply with
3.2.4.1, the cargo control room shall have no access to the spaces described
above and the boundaries for such spaces shall be insulated to "A-60"
class.
3.4.2 If the cargo control room is designed to be a
non-hazardous area, instrumentation shall, as far as possible, be by indirect
reading systems and shall, in any case, be designed to prevent any escape of gas
into the atmosphere of that space. Location of the gas detection system within the
cargo control room will not cause the room to be classified as a hazardous area, if
installed in accordance with 13.6.11.
3.4.3 If the cargo control room for ships carrying
flammable cargoes is classified as a hazardous area, sources of ignition shall be
excluded and any electrical equipment shall be installed in accordance with chapter
10.
3.5
Access to spaces in the cargo area
3.5.1 Visual inspection of at least one side of the
inner hull structure shall be possible without the removal of any fixed structure or
fitting. If such a visual inspection, whether combined with those inspections
required in 3.5.2, 4.6.2.4 or 4.20.3.7 or not, is only possible at the outer face of
the inner hull, the inner hull shall not be a fuel-oil tank boundary wall.
3.5.2 Inspection of one side of any insulation in hold
spaces shall be possible. If the integrity of the insulation system can be verified
by inspection of the outside of the hold space boundary when tanks are at service
temperature, inspection of one side of the insulation in the hold space need not be
required.
3.5.3 Arrangements for hold spaces, void spaces, cargo
tanks and other spaces classified as hazardous areas, shall be such as to allow
entry and inspection of any such space by personnel wearing protective clothing and
breathing apparatus and shall also allow for the evacuation of injured and/or
unconscious personnel. Such arrangements shall comply with the following:
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.2 The dimensions referred to in 3.5.3.1.2 and
3.5.3.1.3 may be decreased, if the requirements of 3.5.3 can be met to the
satisfaction of the Administration.
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.3 Where cargo is carried in a containment
system requiring a secondary barrier, the requirements of 3.5.3.1.2 and
3.5.3.1.3 do not apply to spaces separated from a hold space by a single
gastight steel boundary. Such spaces shall be provided only with direct or
indirect access from the weather deck, not including any enclosed
non-hazardous area.
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.4 Access required for inspection shall be a
designated access through structures below and above cargo tanks, which
shall have at least the cross-sections as required by 3.5.3.1.3.
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.5 For the purpose of 3.5.1 or 3.5.2, the
following shall apply:
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.1 where it is required to pass between
the surface to be inspected, flat or curved, and structures such as
deck beams, stiffeners, frames, girders, etc., the distance between
that surface and the free edge of the structural elements shall be
at least 380 mm. The distance between the surface to be inspected
and the surface to which the above structural elements are fitted,
e.g. deck, bulkhead or shell, shall be at least 450 mm for a curved
tank surface (e.g. for a type C tank), or 600 mm for a flat tank
surface (e.g. for a type A tank) (see figure 3.1);
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.2 where it is not required to pass
between the surface to be inspected and any part of the structure,
for visibility reasons the distance between the free edge of that
structural element and the surface to be inspected shall be at least
50 mm or half the breadth of the structure's face plate, whichever
is the larger (see figure 3.2);
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.3 if for inspection of a curved
surface where it is required to pass between that surface and
another surface, flat or curved, to which no structural elements are
fitted, the distance between both surfaces shall be at least 380 mm
(see figure 3.3). Where it is not required to pass between that
curved surface and another surface, a smaller distance than 380 mm
may be accepted taking into account the shape of the curved
surface;
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.4 if for inspection of an
approximately flat surface where it is required to pass between two
approximately flat and approximately parallel surfaces, to which no
structural elements are fitted, the distance between those surfaces
shall be at least 600 mm. Where fixed access ladders are fitted, a
clearance of at least 450 mm shall be provided for access (see
figure 3.4);
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.5 the minimum distances between a
cargo tank sump and adjacent double bottom structure in way of a
suction well shall not be less than those shown in figure 3.5
(figure 3.5 shows that the distance between the plane surfaces of
the sump and the well is a minimum of 150 mm and that the clearance
between the edge between the inner bottom plate, and the vertical
side of the well and the knuckle point between the spherical or
circular surface and sump of the tank is at least 380 mm). If there
is no suction well, the distance between the cargo tank sump and the
inner bottom shall not be less than 50 mm;
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.6 the distance between a cargo tank
dome and deck structures shall not be less than 150 mm (see figure
3.6);
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.7 fixed or portable staging shall be
installed as necessary for inspection of cargo tanks, cargo tank
supports and restraints (e.g. anti-pitching, anti-rolling and
anti-flotation chocks), cargo tank insulation etc. This staging
shall not impair the clearances specified in 3.5.3.5.1 to 3.5.3.5.4;
and
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.8 if fixed or portable ventilation
ducting shall be fitted in compliance with 12.1.2, such ducting
shall not impair the distances required under 3.5.3.5.1 to
3.5.3.5.4.
3.5.4 Access from the open weather deck to
non-hazardous areas shall be located outside the hazardous areas as defined in
chapter 10, unless the access is by means of an airlock in accordance with 3.6.
3.5.5 Turret compartments shall be arranged with two
independent means of access/egress.
3.5.6 Access from a hazardous area below the weather
deck to a non-hazardous area is not permitted.
3.6 Airlocks
3.6.1 Access between hazardous area on the open weather
deck and non-hazardous spaces shall be by means of an airlock. This shall consist of
two self-closing, substantially gastight, steel doors without any holding back
arrangements, capable of maintaining the overpressure, at least 1.5 m but no more
than 2.5 m apart. The airlock space shall be artificially ventilated from a
non-hazardous area and maintained at an overpressure to the hazardous area on the
weather deck.
3.6.2 Where spaces are protected by pressurization, the
ventilation shall be designed and installed in accordance with recognized
standardsfootnote.
3.6.3 An audible and visible alarm system to give a
warning on both sides of the airlock shall be provided. The visible alarm shall
indicate if one door is open. The audible alarm shall sound if doors on both sides
of the air lock are moved from the closed positions.
3.6.4 In ships carrying flammable products, electrical
equipment that is located in spaces protected by airlocks and not of the certified
safe type, shall be de-energized in case of loss of overpressure in the space.
3.6.5 Electrical equipment for manoeuvring, anchoring
and mooring, as well as emergency fire pumps that are located in spaces protected by
airlocks, shall be of a certified safe type.
3.6.6 The airlock space shall be monitored for cargo
vapours (see 13.6.2).
3.6.7 Subject to the requirements of the International
Convention on Load Lines in force, the door sill shall not be less than 300 mm in
height.
3.7 Bilge, ballast and oil fuel arrangements
3.7.1 Where cargo is carried in a cargo containment
system not requiring a secondary barrier, suitable drainage arrangements for the
hold spaces that are not connected with the machinery space shall be provided. Means
of detecting any leakage shall be provided.
3.7.2 Where there is a secondary barrier, suitable
drainage arrangements for dealing with any leakage into the hold or insulation
spaces through the adjacent ship structure shall be provided. The suction shall not
lead to pumps inside the machinery space. Means of detecting such leakage shall be
provided.
3.7.3 The hold or interbarrier spaces of type A
independent tank ships shall be provided with a drainage system suitable for
handling liquid cargo in the event of cargo tank leakage or rupture. Such
arrangements shall provide for the return of any cargo leakage to the liquid cargo
piping.
3.7.4 Arrangements referred to in 3.7.3 shall be
provided with a removable spool piece.
3.7.5 Ballast spaces, including wet duct keels used as
ballast piping, oil fuel tanks and non-hazardous spaces, may be connected to pumps
in the machinery spaces. Dry duct keels with ballast piping passing through may be
connected to pumps in the machinery spaces, provided the connections are led
directly to the pumps, and the discharge from the pumps is led directly overboard
with no valves or manifolds in either line that could connect the line from the duct
keel to lines serving non-hazardous spaces. Pump vents shall not be open to
machinery spaces.
3.8
Bow and stern loading and unloading arrangements
3.8.1 Subject to the requirements of this section and
chapter 5, cargo piping may be arranged to permit bow or stern loading and
unloading.
3.8.2 Bow or stern loading and unloading lines that are
led past accommodation spaces, service spaces or control stations shall not be used
for the transfer of products requiring a type 1G ship. Bow or stern loading and
unloading lines shall not be used for the transfer of toxic products as specified in
1.2.53, where the design pressure is above 2.5 MPa.
3.8.3 Portable arrangements shall not be permitted.
3.8.4.1 Entrances, air inlets and openings to
accommodation spaces, service spaces, machinery spaces and controls stations, shall
not face the cargo shore connection location of bow or stern loading and unloading
arrangements. They shall be located on the outboard side of the superstructure or
deckhouse at a distance of at least 4% of the length of the ship, but not less than
3 m from the end of the superstructure or deckhouse facing the cargo shore
connection location of the bow or stern loading and unloading arrangements. This
distance need not exceed 5 m.
3.8.4.2 Windows and sidescuttles facing the shore
connection location and on the sides of the superstructure or deckhouse within the
distance mentioned above shall be of the fixed (non-opening) type.
3.8.4.3 In addition, during the use of the bow or stern
loading and unloading arrangements, all doors, ports and other openings on the
corresponding superstructure or deckhouse side shall be kept closed.
3.8.4.4 Where, in the case of small ships, compliance
with 3.2.4.1 to 3.2.4.4 and 3.8.4.1 to 3.8.4.3 is not possible, the Administration
may approve relaxations from the above requirements.
3.8.5 Deck openings and air inlets and outlets to
spaces within distances of 10 m from the cargo shore connection location shall be
kept closed during the use of bow or stern loading or unloading arrangements.
3.8.6 Firefighting arrangements for the bow or stern
loading and unloading areas shall be in accordance with 11.3.1.4 and 11.4.6.
3.8.7 Means of communication between the cargo control
station and the shore connection location shall be provided and, where applicable,
certified for use in hazardous areas.