| April 30, 2007
(Houston, TX) Regulations governing the carriage of specified liquid chemicals by offshore support vessels (OSV) changed with the introduction of amendments to MARPOL Annex II and the IBC Code that took effect 1 January 2007, yet designers and operators are still struggling to clarify the impact the changes will have on their activities.
ABS, as the leading classification society providing services to the offshore sector, has been asked by the U.S. Coast Guard to provide input on the manner in which previously recommendatory provisions have been implemented as the agency develops specific requirements that will govern the application of the new regulations. “We are also responding to many requests from our clients, both the shipyards and the operators, for clarification of what the new regulations mean and how compliance can be established,” says Philip G Rynn, ABS Senior Staff Consultant with responsibility for this area of activity.
IMO’s Marine Safety Committee (MSC) has established two sets of guidelines (MSC.236(82) and MSC.235(82) ) governing the carriage of chemicals. One addresses the operational aspects of transporting and handling the designated liquids and the other covers design and construction elements. And a working group within IMO has prepared a set of amendments to the Liquid Substances in Bulk on Offshore Support Vessels (LHNS Guidelines, resolution A.673 (16)). And there has been a further revision of A.673 based on the IMO’s MEPC.158(55).
“All OSVs will be required to comply with the operational and handling requirements,” says Rynn. “That element is relatively straightforward, although the number of products that are now covered has been increased from 11 to 31” including such frequently handled liquids as methyl alcohol (methanol). Other elements addressed include handling residues either through load-on-top procedures or discharge to shore reception facilities.
The greater concern, and confusion, surrounds the new design requirements, Rynn points out. “In future, these products must be carried in protectively located tanks,” he says. “Essentially, the new regulations demand that OSVs be double hulled with a minimum 760mm gap between the outer shell plating and the tanks that will be used to carry the designated products. That means cost increases for new vessels due to the additional steel, increased production time, more complex piping arrangements and also enhanced fire fighting capability.”
What is not yet clear, with the industry awaiting a final ruling from the U.S. Coast Guard, is the definition of an ‘existing vessel’. This definition may also differ between different coastal and flag states introducing further confusion. “The problem is that these have been recommendatory IMO procedures since 1990,” Rynn explains. “At ABS, we adopted the standards into our Rules for these vessels in 1997. The Coast Guard has been warning industry of the pending adoption of the new regulations since 2004. Additionally, in some areas, the proposed USCG requirements are even stricter than the international standards established by IMO.
“Now, with the 1 January 2007 effective date for the MARPOL amendments, it is not clear which vessels will be grandfathered and which vessels will need to be modified if they are to be permitted to continue carrying these products. And it appears likely that the requirements will vary depending upon where in the world the vessels are operating.”
Whatever the outcome Rynn says it is likely that a large number of OSVs will need to be modified, if they are to continue to have the operational flexibility to carry all 31 of the designated products.
Rynn admits that the subject is complex. “The one advantage we have at ABS is that we have been involved in this process for a long time, at IMO and in discussions with the U.S. Coast Guard, so we do have a deep understanding of the issues and of the technical requirements,” he explains. “We are able to draw on that experience in providing guidance to the designers, builders and owners of these industry workhorses.
“As soon as the Coast Guard issues the necessary definitions and clarifications, we will be in a position to assist our industry partners to quickly develop technical and operational strategies to bring them into compliance.”
ABS currently classes approximately 800, or one third of the world’s fleet of offshore supply and support vessels. An additional 350 such vessels are currently on order or under construction to ABS class.
Founded in 1862, ABS is a leading international classification society devoted to promoting the security of life, property and the marine environment through the development and verification of standards for the design, construction and operational maintenance of marine-related facilities.
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