Super-rust" threat

Citation

(2001), "Super-rust" threat", Disaster Prevention and Management, Vol. 10 No. 5. https://doi.org/10.1108/dpm.2001.07310eab.006

"Super-rust" threat

"Super-rust" threat

A potent new form of corrosion, dubbed "super-rust", could threaten a whole generation of ageing product tankers, and possibly also newer double-hulled vessels.

Evidence of the threat comes from a probe into one of the recent spate of product tanker casualties which have pushed safety concerns to the forefront of industry debate.

Although many tanker owners may flinch at the prospect of new regulations and more stringent surveys, leading classification societies are already forming the view that more has to be done. American Bureau of Shipping chairman Frank Iarossi, scheduled to speak at a conference in London, was expected to drop a bombshell when he reveals that "super-rust" lay behind the potentially catastrophic crack which opened on the deck of the product tanker Castor on 31 December.

Lloyd's List understands that the investigation ABS launched jointly with Cyprus' Department of Merchant Shipping has uncovered rates of corrosion on the ship's deck that staggered experienced surveyors.

ABS is likely to push for more regulation to counter the problem. Commenting on today's expected announcement, Stewart Wade, vice-president marketing development and communications at ABS, said: "It will include some stuff which surprised us [and] information which we think that the industry in general will find of interest." He declined to add further details.

Lloyd's List understands that one of the most shocking facts turned up by the ongoing Castor investigation is that even new steel, added to the tanker's deck at her fourth special survey three years ago, was badly wasted.

ABS and Cypriot officials apparently believe that the fact that the new steel was not coated helped corrosion take hold and weaken the deck structure.

As a result, ABS is likely to lobby for adopting specific requirements for coatings as part of IACS' unified class requirements, as well as for beefing up survey requirements so that hidden corrosion is more likely to be detected in the future.

Today's expected announcement from ABS will echo earlier concerns expressed by Italian classification society Rina following the break-up of the 1974-built Kristal.

At the time, Rina's chief executive, Nicola Squassafichi, said: "Following the recent incidents, where similar-aged product tankers in class suffered severe heavy weather structural damage, we are concerned that there may be an industry-wide problem with applicable standards."

Rina yesterday stressed the need to learn from recent casualties such as the Erika, Castor and Kristal. The Italian society highlighted IACS measures, which are aimed at strengthening intermediate survey regimes for tankers and bulk carriers over 15 years.

The beefed-up measures will also include annual inspections of ballast tanks adjacent to heated cargo tanks, amid concern that the atmosphere in the former could be highly corrosive.

"All over the industry there is this concern and it is time to start taking proactive actions in order to avoid further incidents of this kind", said Roberto Cazzulo, head of the technical section of Rina's engineering department.

Much of the previous debate has focused squarely on elderly product tankers such as the Castor, Kristal and Erika which have been at the centre of recent incidents. In the Castor's case, investigators believe that the corrosion was hastened by the vessel's trading pattern and the fact she was mainly employed in transporting gasoline.

A new worry, however, is that ABS and Cypriot officials appear to feel that the problem may not be solely confined to elderly ships, but could potentially afflict ballast spaces in relatively new double-hulled tankers.

(Lloyd's Casualty Week, Vol. 324 No. 3, 13 April 2001)