Circular Letter
MSC/Circ.1071
GUIDELINES FOR BULK CARRIER HATCH COVER SURVEYS AND OWNER'S INSPECTIONS AND
MAINTENANCE
(adopted
on 5 June 2003)
1.
The Maritime Safety Committee, at its seventy-sixth session (2 to 13 December
2002), considered recommendations for decision-making emanating from several
formal safety assessment (FSA) studies on bulk carrier safety covering all
aspects of design, equipment and operation of these ships. In particular, while
recognizing that replacing hatch covers in existing bulk carriers would not be
cost-effective, the Committee agreed that more attention should be paid to
hatch cover securing mechanisms and the issue of horizontal loads, especially
with regard to maintenance and frequency of inspection.
2.
The Committee, at its seventy-seventh session (28 May to 6 June 2003), having
considered a recommendation made by the Sub-Committee on Ship Design and
Equipment at its forty-sixth session, approved the Guidelines for bulk carrier
hatch cover maintenance and surveys set out in the Annex to this circular.
3.
Member Governments are invited to ensure that Companies, as defined in the ISM
Code, that operate bulk carriers flying their flag are made aware of the need
to implement regular maintenance and inspection procedures for hatch cover
closing mechanisms in existing bulk carriers in order to ensure proper
operation and efficiency at all times, as provided in the annexed Guidelines.
4.
Member Governments are further invited to ensure that classification societies
acting on their behalf that are involved in the survey of bulk carrier hatch
covers are also made aware of, and observe, the survey procedures outlined in
the Guidelines.
ANNEX.
GUIDELINES FOR BULK CARRIER HATCH COVER SURVEYS AND OWNER'S INSPECTIONS AND
MAINTENANCE
These
Guidelines are intended primarily for large steel hatch covers on bulk carriers
to which SOLAS chapter XII applies. However they may also be relevant to other
minimum freeboard ship types having steel covers in exposed positions.
2.1
Recent research has quantified the magnitude of sea load pressures acting on
the side and end faces of hatch covers and on hatch coamings. This has revealed
substantial green sea loading pressures which may generate lateral forces well
in excess of the capability of some hatch cover securing devices. These forces
cause significant loading on hatch cover travel stops and securing devices, and
are only partially resisted by frictional and clearing forces.
2.2
The strength of securing devices of hatch covers on all ships should therefore
be reviewed by the Administration. The review should ensure that the
weathertightness of each cover is not likely to be impaired having regard to
the service in which the ship is engaged and the location of the hatchway.
Where hatch covers or coamings undergo substantial repair, the strength of
securing devices should be brought up to the relevant standard for new
construction.
2.3
Hydraulic cleating systems are generally preferable to manual cleats from the
operability standpoint on large hatch covers. Where hydraulic cleating is used,
the system should be protected against release by incorporating mechanical
securing devices. IACS Recommendation 14 contains such guidance.
2.4
The cleating and securing devices should be designed or otherwise arranged to
be readily visible, so as to facilitate checking proper and complete securing
of hatch covers during a voyage.
2.5
Manufacturers should provide recommendations on the safe operation, inspection,
maintenance and repair of each type of hatch cover fitted, with a recommended
list of spare parts to be carried aboard. This guidance should include
recommendations for the periodic renewal of components subject to wear or
ageing. A maintenance record sheet should also be provided to document owner's
inspections and maintenance planning in accordance with the International
Safety Management Code (ISM Code).
3. Maintenance of hatch covers and hatch
opening, closing, securing and sealing systems
3.1
Lack of weathertightness may be attributed to:
.1 normal use of the hatch
cover system, such as deformation of the hatch coaming or cover due to impact,
wear of the friction pads where fitted, or wear and tear of the cleating
arrangement which may be corrected by a rebuild to restore the original
specification; or
.2 lack of maintenance such
as corrosion of plating and stiffeners due to breakdown of coatings, lack of
lubrication of moving parts; cleats, joint gaskets and rubber pads in need of
replacement, or replaced with incorrect specification parts.
3.2
Insecure hatch covers may be particularly attributed to damage or wear of
securing devices, and incorrect adjustment, hence incorrect pretension and load
sharing, of clearing systems.
3.3
Shipowners and operators should institute a programme of maintenance. This
maintenance should be directed to:
.1 protecting exposed
surfaces of plating and stiffeners of hatch covers and coamings in order to
preserve overall structural strength;
.2 preserving the surface of
trackways of rolling covers, and of compression bars and other steel work
bearing on seals or friction pads, noting that surface smoothness and correct
profile are important for reducing wear rates on these components;
.3 maintaining hydraulic or
mechanically powered opening, closing securing or cleating systems in
accordance with manufacturers recommendations;
.4 maintaining manual cleats
in adjustment, with replacement on significant wastage, wear or loss of
adjustment capability;
.5 replacing seals and other
wear components in accordance with manufacturers recommendations, noting the
need to carry aboard or obtain such spares of correct specification, and that
seals are designed for a particular degree of compression, hardness, chemical
and wear resistance; and
.6 keeping peripheral and
cross joint drains, where fitted, in working order, noting that any drains
fitted to the inboard side of seal lines will have non return valves for
prevention of water ingress to holds in the event of boarding seas.
3.4
It is recommended that renewal of components such as seals, rubber washers,
peripheral and cross joint cleats are made at least as a panel set, to
facilitate equalisation of securing loads.
3.5
Shipowners and operators are recommended to maintain a record of maintenance,
and component replacement, to facilitate statutory surveys by the
Administration. All major repairs should be undertaken only after consultation
with the hatch cover manufacturer and with the approval of the Administration.
Hatch cover maintenance plans should form part of a ship's safety management
system as referred to in the ISM Code.
3.6
Where a range of cargoes carried requires different gasket materials, a
selection of gasket materials of the correct specification should be carried
aboard, in addition to other spares.
3.7
At each operation of a hatch cover, the cover, and in particular bearing
surfaces and drainage channels, should be free of debris and as clean as
practicable.
3.8
Attention is drawn to the dangers of proceeding to sea without fully secured
hatch covers. Securing of all covers should always be completed before the
commencement of a sea passage. During voyages, especially on loaded passages,
cover securing devices and tightness of cleating and securing arrangements
should be checked, especially in anticipation of and following periods of
severe weather.
3.9
Containers and other cargoes should not be stowed on hatch covers unless the
covers are designed and approved for such carriage. Lashings should not be
secured to the covers or coamings unless these are designed to withstand the
lashing forces. It is therefore particularly important to consult the cargo
securing manual when loading on deck.
4. Survey of hatch covers and hatch opening,
closing, securing and sealing systems
4.1
Statutory surveys of hatchcovers and their coamings are to be carried out by
the Administration as part of the annual survey required by Article 14 of the
International Convention on Load Lines, as modified by the 1988 Protocol
relating thereto. On ships subject to the Guidelines on the enhanced programme
of inspections during surveys of bulk carriers and oil tankers (resolution
A.744(18), as amended) these should be surveyed taking into account the
guidance in paragraph 3.3 of Annex A to the said Guidelines.