Section
1 Ship Arrangements
1.1 Segregation of the cargo area and cargo
tank holds
1.1.1 In addition to the requirements outlined in this Section, the
requirements of Pt 3, Ch 2 Drilling Units are to be complied with.
1.1.2 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 17, after further
consideration of involved risks, including that of cargo release and the means of
mitigation.
1.1.3 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 Pt 11, Ch 3, 1.1 Segregation of the cargo area and cargo tank holds 1.1.2
or spaces either below or outboard of the hold spaces may be effected by cofferdams,
fuel oil 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.
1.1.4 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
Pt 11, Ch 3, 1.1 Segregation of the cargo area and cargo tank holds 1.1.2,
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 fuel oil tanks. A
gastight A-0 class division is acceptable if there is no source of ignition or fire
hazard in the adjoining spaces.
1.1.5 Segregation of turret compartments from spaces referred to in Pt 11, Ch 3, 1.1 Segregation of the cargo area and cargo tank holds 1.1.2,
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.
1.1.7 When cargo is carried in a cargo containment system requiring a complete
or partial secondary barrier:
- at temperatures below –10°C, hold spaces shall be segregated
from the sea by a double bottom; and
- at temperatures below –55°C, the ship unit shall also have a
longitudinal bulkhead forming side tanks.
1.1.8 Arrangements shall be made for sealing the weather decks in way of
openings for cargo containment systems.
1.1.9 Cargo tank holds are to be separated from each other by single bulkheads
of all welded construction. Where, however, the cargo design temperature as defined
in Pt 11, Ch 4, 1.1 Definitions is below –55°C,
cofferdams are to be adopted unless the cargo is carried in independent tanks and
alternative arrangements are made to ensure the bulkhead cannot be cooled to below
–55°C. Cofferdams may be used as ballast tanks, subject to approval by Lloyd’s
Register (LR).
1.2 Accommodation, service and machinery
spaces and control stations
1.2.1 No accommodation space, service space (except cargo service spaces,
see
Pt 11, Ch 3, 1.2 Accommodation, service and machinery spaces and control stations 1.2.2
or topsides service spaces) or control station shall be located within the cargo
area. The bulkhead of accommodation spaces, service spaces (except cargo and
topsides 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 unit having a containment system
requiring a secondary barrier. Cargo, topsides and turret service spaces (i.e.
workshops, store rooms, etc.) and machinery spaces located above the cargo storage
areas, which are impacted by hazardous areas, are to be in accordance with the
requirements of Pt 7, Ch 2, 4 Enclosed and semi-enclosed spaces with access to a hazardous area.
1.2.2 Cargo service spaces as defined in Pt 11, Ch 1, 1.3 Definitions may be situated within cargo areas, provided all other relevant
requirements of these Rules are complied with.
1.2.3 In order to guard against the danger of hazardous vapours, due
consideration should 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. See
Pt 7, Ch 2 Hazardous Areas and Ventilation, regarding the air intakes/outlets and openings to
enclosed non hazardous areas.
1.2.4 As far as practicable, access doors or other openings should not be
provided between a non-hazardous space and a hazardous area or space, or between
Zone 2 and a Zone 1 space, as defined in Pt 11, Ch 10 Electrical Installations. Where such openings are necessary, access from the
accommodation, service spaces, machinery spaces or any other defined non hazardous
enclosed areas on topsides, deck, turret or within the hull are to be in compliance
with Pt 7, Ch 2, 4 Enclosed and semi-enclosed spaces with access to a hazardous area.
1.2.5 Entrances, air inlets and openings to accommodation spaces and hull
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 per cent of the
load line length, L, as defined in Pt 11, Ch 1, 1.3 Definitions of the ship unit 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.
- 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 for
navigational purposes may be non-fixed and wheelhouse doors may be located
within the above limits so long as they are designed in a manner such that a
rapid and efficient gas and vapour tightening of the wheelhouse can be
ensured.
- Access to forecastle spaces containing sources of ignition may
be permitted through door access facing the cargo area, provided the doors
are either located a suitable distance outside hazardous areas as defined in
Pt 11, Ch 10 Electrical Installations or are in accordance
with the requirements of Pt 7, Ch 2, 4 Enclosed and semi-enclosed spaces with access to a hazardous area.
1.2.6 Windows and sidescuttles facing the cargo area and on the sides of the
superstructures and deckhouses within the limits specified in Pt 11, Ch 3, 1.2 Accommodation, service and machinery spaces and control stations 1.2.5,
except wheelhouse windows for navigational purposes where applicable, shall be
constructed to at least A-60 class. Wheelhouse windows for navigational purposes
shall be constructed to at least A-0 class (for external fire load). 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. It should be noted
that the above minimum class of windows should be confirmed for their suitability
within the installation Fire and Explosion Evaluation (FEE). If necessary, higher
rated windows or alternative designs without windows may be required dependent upon
the findings of the FEE.
1.2.7 All air intakes, outlets and other openings into the accommodation
spaces, service spaces and control stations shall be fitted with closing devices.
For toxic gases, they shall be operated from inside the space. Air intakes and
outlets and the protection against gas ingress into all accommodation spaces,
service spaces and control stations are to be in accordance with the requirements of
Pt 7, Ch 1, 5 Protection against gas ingress into safe areas and Pt 7, Ch 2, 6.1 General requirements.
1.2.8 Control rooms and machinery spaces of turret systems may be located in
the cargo area forward or aft of cargo tanks in ship units 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 in accordance with the requirements of Pt 7, Ch 2, 4 Enclosed and semi-enclosed spaces with access to a hazardous area.
1.2.9 Any topsides or turret service spaces or machinery spaces shall
generally be treated for the purpose of fire containment according to SOLAS
Regulation
2.4 Tankers. However, alternative fire
protection and fire mitigating measures may be considered to be appropriate
following assessment via the installation Fire and Explosion Evaluation (FEE),
dependent upon the installation’s fire-fighting and safety philosophy.
1.2.10 Arrangements of any topsides or turret service spaces or machinery
spaces should 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 each service space, except that a single escape route may be accepted
where the maximum travel distance to the door is 5 m or less.
1.3 Cargo machinery spaces and turret
compartments
1.3.1 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
2.4 Tankers, and for the purpose of
prevention of potential explosion according to SOLAS
5.10 Protection of
cargo pump-rooms.
1.3.2 When cargo machinery spaces are located at the after end of the aftermost
hold space or at the forward end of the forwardmost hold space, the limits of the
cargo area, as defined in Pt 11, Ch 1, 1.3 Definitions, shall be extended to include the cargo machinery spaces for the
full breadth and depth of the ship unit and the deck areas above those spaces.
1.3.3 Where the limits of the cargo area are extended by Pt 11, Ch 3, 1.3 Cargo machinery spaces and turret compartments 1.3.2,
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.
1.3.4 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 gas-tight segregation of the two spaces.
Where these cargo compressors and cargo pumps are located in hazardous areas, they
are to comply with Pt 7, Ch 2, 5.1 General 5.1.2. Alternatively the use
of motor compressor and motor pump sets with the complete package certified for use
in hazardous areas is acceptable.
1.3.5 Arrangements of cargo machinery spaces and turret compartments should
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.
1.3.6 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.
1.3.7 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. See also
Pt 10, Ch 2, 5.2 Blast condition.
1.4 Cargo control rooms
1.4.1 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:
- the cargo control room is a non-hazardous area;
- if the entrance complies with Pt 11, Ch 3, 1.2 Accommodation, service and machinery spaces and control stations 1.2.5,
the control room may have access to the spaces described above;
- if the entrance does not comply with Pt 11, Ch 3, 1.2 Accommodation, service and machinery spaces and control stations 1.2.5
the cargo control room shall have no access to the spaces described
above and the boundaries for such spaces shall be insulated to at
least A-60 class or higher. It should be noted that the minimum fire
class of a cargo control room’s boundaries should be confirmed for
their suitability within the installation Fire and Explosion
Evaluation (FEE). If necessary, higher rated fire boundaries may be
required, dependent upon the findings of the FEE.
1.4.2 If the cargo control room is designed to be a non-hazardous area,
instrumentation should, 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
Pt 11, Ch 13, 1.6 Gas detection 1.6.10.
1.5 Access to spaces in the cargo area
1.5.1 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 or not combined with those inspections required in Pt 11, Ch 3, 1.5 Access to spaces in the cargo area 1.5.2 or
Pt 11, Ch 4 Cargo Containment, is only possible at
the outer face of the inner hull, the inner hull shall not be a fuel oil tank
boundary wall.
1.5.2 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.
1.5.3 Arrangements for hold spaces, void spaces, cargo tanks and other spaces
defined as hazardous areas in Pt 11, Ch 10 Electrical Installations and Pt 7, Ch 2, 2 Classification of 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:
- Access shall be provided:
- To all cargo tanks, access shall be direct from the
weather deck.
- Access through horizontal openingş
hatches or manholes, the dimensions shall be sufficient to allow a
person wearing a breathing apparatus to ascend or descend any ladder
without obstruction and also to provide a clear opening to
facilitate the hoisting of an injured person from the bottom of the
space the minimum clear opening shall be not less than 600 mm × 600
mm; and
- Access through vertical openings or
manholes providing passage through the length and breadth of the
space, the minimum clear opening shall be not less than 600 mm x 800
mm at a height of not more than 600 mm from the bottom plating
unless gratings or other footholds are provided.
- Circular access openings to Type C tanks shall have a
diameter of not less than 600 mm.
- The dimensions referred to in (a)(ii) and (a)(iii) may be
decreased if the requirements of Pt 11, Ch 3, 1.5 Access to spaces in the cargo area 1.5.3
can be met to the satisfaction of the Administration.
- Where cargo is carried in a containment system requiring a
secondary barrier the requirements of (a)(ii) and (a)(iii) 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.
- Access required for inspection shall be provided as follows:
- Designated access through structures below and above
cargo tanks shall have at least the cross sections as required by
(a)(iii)
- For the purpose of Pt 11, Ch 3, 1.5 Access to spaces in the cargo area 1.5.1
or Pt 11, Ch 3, 1.5 Access to spaces in the cargo area 1.5.2
the following shall apply:
- 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 3.1.1 Minimum
passage clearance for tank inspection in way of ship
structural members).
Figure 3.1.1 Minimum
passage clearance for tank inspection in way of ship
structural members
- 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 face plate of the structure, whichever is the larger.
See
Figure 3.1.2 Minimum
visibility clearance for tank inspection in way of ship
structural members.
Figure 3.1.2 Minimum
visibility clearance for tank inspection in way of ship
structural members
- 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 3.1.3 Minimum
passage clearance for tank inspection between
surfaces.
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.
Figure 3.1.3 Minimum
passage clearance for tank inspection between
surfaces
- 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 3.1.4 Minimum
access clearance in way of fixed access ladders.
Figure 3.1.4 Minimum
access clearance in way of fixed access ladders
- 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 3.1.5 Minimum distances between cargo tank sump and adjacent
double bottom structure in way of a section well. If
there is no suction well the distance between the cargo tank sump
and the inner bottom shall not be less than 50 mm.
NOTE
- The distance between a cargo tank dome and deck
structures shall not be less than 150 mm. See
Figure 3.1.6 Minimum
distance between cargo tank dome and deck structure.
Figure 3.1.6 Minimum
distance between cargo tank dome and deck structure
- 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 (i) to (v) .
- If fixed or portable ventilation ducting is to be
fitted in compliance with Pt 11, Ch 12, 1.2 Spaces not normally entered (i) to (v), such ducting shall not impair the
distances required under (i) to (iv) .
1.5.4 In general, the requirements for minimum clear opening given in Pt 11, Ch 3, 1.5 Access to spaces in the cargo area 1.5.3.(a).(ii)
and Pt 11, Ch 3, 1.5 Access to spaces in the cargo area 1.5.3.(a).(iii)
are also to be adhered to for spaces separated by a single gastight steel boundary
from a hold space where cargo is carried in a cargo containment system requiring a
secondary barrier. Reference is made to IACS Interpretations of the IMO Code for
the Construction and Equipment of Ships carrying Liquefied Gases in Bulk No.
GC6.
For ship units complying with the requirements for Type A independent
tanks, manholes will not be permitted through the secondary barrier, except through
the upper deck in regions which are above the predicted surface of the cargo
assuming total failure of the cargo tank and the ship unit at 30 degrees heel port
or starboard. Alternative structural arrangement will be specially considered.
1.5.6 Turret compartments shall be arranged with two independent means of
access/egress. The access/egress routes are to 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. A single escape route may be
accepted for turret compartments where the maximum travel distance to the door is 5
m or less.
1.6 Airlocks
1.6.1 Access between hazardous areas 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 over pressure, 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.
1.6.3 The relative air pressure within the non hazardous enclosure is to be
continuously monitored and so arranged that, in the event of loss of overpressure,
an alarm is given at a manned control station.
1.6.4 For electrical equipment that is located in enclosed non hazardous
spaces, is not certified for operation in a Zone 1 hazardous area and does not have
to remain operational during catastrophic conditions (i.e. major hydrocarbon release
scenarios), consideration shall be given to de-energising this equipment in case of
confirmed loss of overpressure in the space. If the flammable gas is subsequently
detected within the area all non emergency electrical items of equipment are to be
de-energised immediately.
1.6.5 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.
1.6.7 Subject to the requirements of the International Convention on Load
Lines as amended, the door sill shall not be less than 300 mm in height.
1.6.8 Air locks are to 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.
1.7 Bilge, ballast and fuel oil
arrangements
1.7.1 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.
1.7.2 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.
1.7.3 The hold or interbarrier spaces of Type A independent tank ship units
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.
1.7.5 Ballast spaces, including wet duct keels used as ballast piping, fuel
oil 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.
1.8 Tandem and side-by-side loading and
unloading arrangements
1.8.2 Portable arrangements shall not be permitted.
1.8.3 Entrances, air inlets and openings to accommodation spaces, service
spaces, machinery spaces and controls stations shall not face the cargo connection
location of the unloading arrangements. They shall be located on the outboard side
of the superstructure or deckhouse at a distance of at least 4 per cent of the
length of the ship unit, but not less than 3 m from the end of the superstructure or
deckhouse facing the cargo connection location of the unloading arrangements. This
distance need not exceed 5 m.
- Windows and sidescuttles facing the connection location of the
shuttle tanker and on the sides of the superstructure or deckhouse within
the distance mentioned above shall be of the fixed (non-opening) type.
- In addition, during the use of the unloading arrangements, all
doors, ports and other openings on the corresponding superstructure or
deckhouse side should be kept closed.
1.8.4 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
the unloading arrangements.
1.8.6 Means of communication between the cargo control station and the
connection location of the shuttle tanker shall be provided and where applicable
certified for use in hazardous areas.
1.8.7 Hull, hull weather deck and liquefied gas offloading arrangements shall
generally be treated for the purpose of fire containment according to SOLAS
Regulation
2.4 Tankers and for fire mitigation
according to Pt 11, Ch 11 Fire Prevention and Extinction . However, alternative fire protection and fire
mitigating measures may be considered to be appropriate following assessment via the
installation Fire and Explosion Evaluation (FEE), dependent upon the installation’s
fire-fighting and safety philosophy.
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