Double sides and raised bow in ?07

Just occasionally a meeting takes place where coincidental events that are making news headlines elsewhere focus the minds of the delegates more strongly on the agenda than they ordinarily would be, resulting in the passing of tough resolutions.

The recent meeting of the IMO?s Maritime Safety Committee (MSC) was one such meeting. It took place in early December 2002 at a time when newspapers were full of stories on Prestige and the aftermath of the ship?s troubles and ultimate sinking off northwest Spain. Prestige, of course, was a tanker and the MSC?s agenda for its 76th session did not include tanker safety. However it did include bulk carrier safety.

“Prestige changed the mood in the committee,” says Hans Viig, senior vice president responsible for bulk carrier corporate marketing in DNV and a delegate at the two-week MSC meeting. “There was a willingness to make decisions and to finalise matters that have been up for discussion for some time. Delegations understood that they must be seen to act now to prevent the IMO from being sidelined [by the EU, for example].”

The result was a session during which a number of far-reaching measures were introduced to prevent and mitigate against water ingress into cargo holds, the major cause of bulk carrier casualties:

l it was agreed in principle that all bulk carriers built after 2007 will require double ship sides

l amendments were made to Solas Chapter XII requiring double sided bulk carriers to withstand flooding of any single cargo hold

l new requirements were set for bow height and forward buoyancy of new bulk carriers through a modification to the Load Line Convention, and significant increases of the design load on hatches and deck fittings

l it was agreed that all new and existing bulk carriers should be fitted with water ingress alarms in each cargo hold and all forward spaces (except the chain locker), within one year of July 1, 2004

Recognising that accidents can still happen (and that when they do on bulk carriers they frequently result in the ship sinking very quickly), the MSC also agreed that a freefall lifeboat with freefloat mode should be fitted to new bulk carriers post-2007 to enable rapid evacuation.

The MSC has tasked its various sub-committees to undertake the practical preparatory work needed to implement the measures in a way that results in improved safety. These include establishing standards for corrosion protection within the double side space and, as a matter of urgency, for the performance standards of water ingress alarms.

It also tasked the sub-committees to examine measures to further reduce the sinking risk of existing single-hull bulk carriers unable to withstand flooding of one cargo hold. The IMO decided in principle that loading cargo in alternate holds on such ships should be outlawed after they reach a certain age and that homogenous loading of cargo holds was required. It is now looking at whether it should enforce rules which would prevent such ships from carrying the densest/heaviest cargoes, or which would increase the minimum freeboard of these vessels from B-60 to B.

Many of the measures agreed upon stem from bulk carrier loss statistics, which show a combination of age and side shell damage are the major causes of bulk carrier casualties. Side shell damage accounts for 50% of bulk carrier casualties, whereas water ingress through the hatches accounts for 20%. Most casualties are on ships over 15 years old.

A double ship side will increase structural redundancy as, for example, the failure of just one main frame won?t result in the collapse of the side shell, as it is likely to on a single side bulk carrier, says Viig. It will also protect stiffeners, frames and brackets from damage during cargo handling operations (by bulldozers, for example) and provide an easy means of access for close-up inspections, as is now required.

Viig argues that significant experience of double sides has been accumulated on container ships and tankers and that the absence of any cargo heating on bulk carriers (with the exception of OBOs) in combination with coating procedures, should prevent hyper-accelerated corrosion in the double side space.

The cost of building a bulk carrier will inevitably increase through the implementation of the new measures. “But absolute price is not important,” argues Viig. “It is the relative price paid compared to a competitor.” As to whether a two-tier charter market might develop, he argues that it might work both ways with there being a possibility that charterers may look upon double sides as a required standard, making single side ships less attractive.

Based on past experience, when a number of open hatch bulk carrier operators switched the class notation of their vessels from bulk carrier to general cargo ship (apparently to sidestep ISM Code requirements), IMO decided to review the definition of a bulk carrier possibly by removing the references to top wing tanks and hopper tanks. This leaves the definition of a bulk carrier simply as: “A ship designed to carry dry bulk cargoes”.

The issue of phasing out existing single side bulk carriers was not on the MSC?s agenda. However it was noted that IACS had introduced tougher standards relating to corrosion. These now require that frames are protected (coated) on single-side bulk carriers and that a 25% corrosion margin is applied to the replacement of frames from the next intermediate or special survey.

Fit-for-purpose bulk carriers

IACS has developed its new Unified Requirement S25 (Harmonised Notations and Corresponding Design Loading Conditions for Bulk Carriers) having resolved the ambiguities, particularly in relation to ballast conditions, that existed in the initial version.

UR S25 was drawn up in response to calls from owners for more robust, fit-for-purpose bulk carriers. These owners felt bulk carriers had become “too optimised”, explains Hans Viig.

Many owners buy bulk carriers on a speculative basis, treating them as a commodity for onward trading, he explains, resulting in shipyards supplying ?commodity? bulk carriers to the minimum required standards in order to meet basic class notation. Under this old system, the awarding of additional notations as standards increase makes it very confusing for brokers and charterers when establishing whether a ship is fit-for-purpose, says Viig.

Under UR S25, the basic class notation has been turned on its head. It will be issued to a bulk carrier built to do everything. Additional notations are awarded as a vessel?s build standard drops from this maximum.

“This is to make it very transparent that there are limitations to these vessels,” explains Viig.

UR S25 will apply to all bulk carriers contracted on or after July 1, 2003.