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      News & EventsRegulatory Information International Regulatory News Updates • MSC 70 Session
Maritime Safety Committee's 70th Session
January 1999

Bulk Carrier Safety

Interpretations of SOLAS Chapter XII

Pursuant to several tasks contained in the 1997 SOLAS Conference resolutions, the MSC issued resolution MSC.79(70) which urges Member States to apply the following clarifications concerning the application of SOLAS Chapter XII to bulk carriers. 4.18

Length limit - the lower length limit of 150m, to which SOLAS Chapter XII applies, should not be lowered unless indicated otherwise by a formal safety assessment scheduled to be carried out in the next 18 months. The MSC noted IACS position that bulk carriers less than 150m would meet the strength requirements, but that considerable difficulty can be expected in complying with flooding stability requirements.

Bulk carrier definition - The resolution reiterates the definition of bulk carrier as per SOLAS Conference Resolution 6 and thus removes ambiguities in the SOLAS Chapter XII definition of bulk carrier, which is the same as the ISM Code definition as per SOLAS regulation IX/1.6. To determine if a ship is a bulk carrier under the ISM Code and the safety requirements for bulk carriers under SOLAS Chapter XII, a "bulk carrier" means a ship constructed with a single deck, top side tanks and hopper side tanks in cargo spaces and intended to primarily carry dry cargo in bulk; an ore carrier; or a combination carrier. Also, recognizing that the accepted legal format of most SOLAS certificates do not indicate the specific type of ship, the resolution indicates that the certificated identification of ship type is as it appears on the ISM Code Safety Management Certificate.

Double sides - Recognizing the reduced probability of water ingress due to shell cracks, corrosion and low energy impact damage when cargo holds are protected from the sea by double sides, the MSC is endeavoring to set a minimum distance in order for a double sided bulk carrier to be exempt from the single side skin requirements of SOLAS Chapter XII. However, this session of MSC could not agree on the minimum distance separating the cargo hold from the side shell. One proposal that was discussed proposed a distance of 760mm for existing bulk carriers built before 1 July 1999 and 1.0m for bulk carriers built after that date. This matter is scheduled to be finalized at MSC 71 in May 1999. In order to preserve the reduced risk of flooding afforded by double sides, the minimum distance should allow for effective access and inspection of the side structure.

Exemptions - Bulk carriers, arranged with an insufficient number of` bulkheads necessary to meet the stability and structural survivability requirements under the provisions of regulations XII/4 and 6, may be exempted from those requirements. However, the resolution clarifies that eligibility for this exemption becomes void if the ship has been modified thereby reducing the number of transverse watertight bulkheads.

Cargo density - It was agreed that on/after 1 July 1999, the declaration of solid bulk cargo density, when between 1250 to 1780 kg/m3, must be verified by an accredited testing organization. This would apply to such cargoes being carried by existing bulk carriers built before 1 July 1999, unless the ship fully complies with SOLAS Chapter XII for bulk carriers carrying cargoes with densities of 1780 kg/m3 and above. Also, it was agreed in principle - subject to discussion at MSC 71 in May 1999 - that bulk carriers, carrying break bulk cargoes with stowage factors of 0.56 m3/ton or less, should be subject to the provisions of SOLAS Chapter XII.


Seakeeping Assessment

The United Kingdom and Greece presented the results of their qualitative and quantitative analyses and computer simulations carried out to determine the sensitivity of the seakeeping performance of bulk carriers in extreme seastates. The U.K. research presents relationships between the susceptibility of deck wetness and deck loads for varying physical aspects, focsle configuration and magnitude of bow height, shape and flare for the 160,000 dwt OBO "Derbyshire".

Although having a different objective than the U.K. research, the Greek research focused on the effects of operational measures such as speed, heading and weather routeing. The research aimed to establish optimal weather routeing (speed and heading) by identifying minimum possible wave induced motions, loads and deck wetness.

By carrying out a parametric analysis for varying headings, speed and wave period and spectral distributions, predictions and trends similar to the U.K.'s work were concluded for 4 different sizes of typical bulk carriers, albeit for a different purpose.

Recognizing the areas where there were corroborating results and considering the impact of operational parameters on seakeeping performance, the MSC agreed that further work in evaluating risks associated with bulk carriers should be performed and that the physical aspects (bow height) and operational aspects (speed and heading) should be jointly considered.

IACS presented the results of its analysis which was used to develop an IACS Unified Requirement on the design loads for the fore end hatch covers. The IACS design loads, applicable to ships built after 1 July 1998, are significantly larger than the loads required by the 1966 Load Line Convention as illustrated below.


After reviewing and discussing the above analyses, the MSC instructed its SLF Sub-Committee to further consider the adequacy of the current regulations relative to:
      - hatch cover/coaming strength;
      - bow height; - reserve buoyancy;
      - mitigation of forward structural loads; and
      - protection of crew access to the bow.

Future sessions of the MSC will consider for new and existing bulk carriers, after completion of the Formal Safety Assessment (FSA) and the IACS hazard identification study (see below), the following issues:
      - loss of steering and the degree of redundancy considering casualty statistics;
      - tank sounding/bilge alarms and emergency pumping;
      - additional training measures, particularly for operation in extreme weather conditions; and
      - free-fall life boat capabilities;

 

 

FSA and HAZID Studies

The MSC endorsed the U.K.'s proposal for a collaborative formal safety assessment study of bulk carriers by Administrations and industry organizations outside the confines of IMO. In light of concerns expressed relative to the broad scope, manner of conduct and prioritization of safety issues of the proposed study, the MSC recommended that the FSA study consider human element aspects as per IMO's draft guidelines and be conducted in accordance with IMO's FSA Interim Guidelines.

IACS is undertaking a hazard identification study on the watertight integrity of the fore end structure of bulk carriers. Scheduled to be completed by May 1999 for MSC 71, the study will evaluate the potential hazards, their causes and consequences. Aspects to be addressed will be the design and operation of closures and systems serving cargo holds and tanks in the fore end of bulk carriers including hatchcovers, airpipes, ventilation trunks, bilge alarms and sounding and emergency pumping systems. Influence of the human element on the effectiveness of the above systems and closures will also be considered.


( + Note: All "ships" are all self propelled vessels)

For further information concerning the above information, please contact ABS Regulatory Affairs Department at telephone (212) 839 5059, by fax (212) 839 5214, or by email Regulatoryaffairs@eagle.org.

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