Circular
Letter
MSC/Circ.1117
GUIDANCE FOR CHECKING THE STRUCTURE OF BULK CARRIERS
(24 June 2004)
1.
The Maritime Safety Committee, at its seventy-eighth session (12 to 21 May
2004), following its decision that port States and the various port State control
regimes worldwide should be strongly recommended to develop specialized
training, pinpointing the vulnerable areas within the structure, in particular
of older ships, and having considered the recommendation made by the
Sub-Committee on Flag State Implementation at its twelfth session, approved the
Guidance for checking the structure of bulk carriers, as set out in the annex.
2.
Member Governments are invited to bring the annexed Guidance to the attention
of all parties concerned.
ANNEX.
GUIDANCE FOR CHECKING THE STRUCTURE OF BULK CARRIERS
1.
This guidance is to assist port State control officers (PSCOs) in checking the
structure as well as the operational aspects of bulk carriers during port State
control inspections.
2.
In addition to this guidance, PSCOs should refer to the following documents:
.1 SOLAS chapter
XII - Additional safety measures for bulk carriers;
.2 resolution
A.862(20) - Code of Practice for the Safe Loading and Unloading of Bulk
Carriers;
.3 resolution
A.866(20) - Guidance to ships crews and terminal personnel for bulk carrier
inspections; and
.4 resolution
A.744(18) as amended Guidelines on the enhanced programme of inspections during
surveys of bulk carriers and oil tankers.
3.
PSCOs are further invited to consult the following IACS publications, if
available:
.1 Bulk
Carriers: Guidelines for Surveys, Assessment and Repair of Hull Structure;
.2 Bulk
Carriers: Guidance and Information on Bulk Cargo Loading and Discharging to
Reduce the Likelihood of Over-Stressing the Hull Structure; and
.3 Bulk Carriers
Handle With Care.
4.
While checking the ship s documentation, PSCOs should pay particular attention
to the loading plan, cargo distribution and loading/unloading sequences to
ascertain that the ship is loaded in accordance with the approved loading
manual.
5.
PSCOs should pay particular attention to the tank top limitation, the bending
moments and shearing forces as well as the cargo distribution. Past experience
shows that ships often load in patterns not approved in the stability manual.
For example, on board a nine-hold bulk carrier, the approved stability manual
often has an annotation stating that holds 2, 4, 6 and 8 may be empty. This
implies that all even number holds must be empty at the same time. In many
cases, ship officers believe that such an annotation allows for any combination
of these holds to be empty, which is not the case.
6.
PSCOs should remember that loading patterns not included in the approved
stability manual should not be accepted since this might create excessive local
stress to the ship s structure regardless of the fact that the bending moments
and shearing forces are within the permissible values.
7.
When it is established during a PSC inspection that a ship loading pattern is
not per the approved stability manuals, the PSCO should request confirmation in
the first instance by the ship s officers, by the flag State administration, or
the recognized organization working on behalf of the flag State, that the
proposed loading plan/distribution is acceptable. In the event that a ship is
found non-compliant with the approved stability manuals during unloading
operations, the PSCO should inform the master and chief officer that future
loading should be within the limitation of the approved stability manual.
8.
Initially, a check of the survey report file may identify possible suspect
areas requiring inspection. The provisions contained in resolution A.744(18) as
amended, require a specific survey programme which includes access arrangements
and, when necessary, the requirements for a close-up survey and thickness
measurements. A survey report file is required to be held on board consisting
of:
.1 reports of
structural surveys;
.2 condition
evaluation reports;
.3 thickness
measurement reports; and
.4 survey
planning document (or equivalent) containing the following information:
.4.1 main
particulars;
.4.2 plan of
tanks and holds;
.4.3 list of
tanks and holds and usage, corrosion protection and condition of coating;
.4.4 corrosion
risk in tanks; and
.4.5 design risk
of structures.
9.
Ideally, inspections should be carried out by a team of at least two PSCOs and
include, at least, one person with an in-depth knowledge of ship structures. In
a loading port they should be ready to board the ship on arrival. In a
discharge port, information on the likely discharge sequences should be
obtained, where possible, so that the inspection can be carried out when holds
become available.
10.
Access to the upper parts of holds is problematic. Ladders may help and
experience has shown that using binoculars along with high-powered torches can
assist in making an initial assessment of the condition of inaccessible parts.
If the condition of other parts of the hold and the hull structure in general
give rise to concern, the flag State/recognized organization should be
consulted to consider the need for a more detailed survey.
11.
The impression of hull maintenance and general state on deck, the condition of
items such as ladders, hatches, air pipes, guardrails, visible evidence of
previously effected repairs, and the condition of deck machinery should
influence the PSCO s decision on whether to make the fullest possible
examination of the hull.
12.
Special attention should be given to areas of high stress and bending moments,
such as: .1 immediately forward of the engine-room bulkhead; .2 over the
midships half-length; and .3 no.1 hold side shell framing and top and bottom
connections (panting region).
13.
Particular attention should be given to areas where fracturing, cracks,
distortion or excessive wastage can occur. These areas are illustrated in the
diagrams in appendices 1 and 2*. The weather tight integrity of hatches and
closures is particularly important on ore carriers with minimal reserve
buoyancy.
______________
* Diagrams in the appendices
are reproduced with the kind permission of IACS, Lloyd s Register and Nippon
Kaiji Kyokai.
14.
Common defects are:
.1 cracking at
hatch corners;
.2 plate panel
buckling of cross deck strips and stiffening structure;
.3 cracking of
hatch coamings;
.4 cracking at
intersection of the inner bottom plating and the hopper plating;
.5 grab and
bulldozer damage to the side shell frames lower brackets;
.6 grab damage
to the inner bottom plating, hopper and lower stool plating;
.7 cracking at
side shell frame bracket toes;
.8 both general
and localized corrosion of side shell frames and brackets;
.9 cracking at
fore and aft extremities of topside tank structures;
.10 corrosion
within topside tanks; and
.11 general
corrosion and cracking of transverse bulkheads.
15.
If tanks or holds are to be inspected, the PSCO should ensure it is safe to
enter. The requirements of the Code of Safe Practice for Solid Bulk Cargoes,
Appendix F, apply. Additional safeguards could include carrying personal
devices capable of determining the safety of tank atmospheres or employing the
services of a chemist to check the atmosphere.
16.
Permanent seawater ballast tanks represent one of the most likely problem areas
and, if inspected, the following aspects