Feature - 6 April 2008 (SPG OffshoreTech)


Slip-Sliding Away Can we grapple with the problem of tanker disasters as the world hopes for a more efficient oil and gas industry? Fleur Doidge reports.

Russia-flagged oil tanker, the Volganeft-139, split apart in November when struck by a 67mph (108km/h) storm with 16ft (5m) waves while at anchor between the Azov and Black Seas, releasing 2,000t of fuel oil into the Kerch Strait and risking the lives of its 13 crewmembers. "The Russia-flagged oil tanker, the Volganeft-139, split apart in November when struck by a 67mph storm." The Soviet-era tanker was reportedly not designed to transport oil anywhere but by river – let alone to withstand violent storms. Accidents, however, aren't restricted to 'outsider' players. A month later, the Hong Kong-registered 146,000t tanker Hebei Spirit collided with a barge-mounted crane near South Korea, leaking 10,000t of crude into the sea. The International Tanker Owners' Pollution Federation (ITOPF) says about 10,000 accidental oil tanker, combined carrier or barge spills have occurred since 1970, and 84% were spills of less than 7t. The average number of large spills (more than 700t) a year in the 1990s was less than a third of that in the 1970s. In 2006, just four spills of more than 700t were recorded – down from 29 in 1970. The few very large spills represent a high percentage of the total oil spilt. For example, 1990 to 1999 saw 358 spills over 7t, totalling 1,138 million tons, but 73% of that was spilt in 3% of incidents. Accidents will happen. But what can be done to reduce their likelihood? And how might their severity be lessened? TANKER TECHNOLOGY Dr David Santillo, a University of Exeter Greenpeace Labs marine biologist, said the Volganeft-139 was, like many ships that have caused devastating spills in the past, a single-hulled tanker. "The Erika spill off France in 1999, the Prestige spill off Spain in 2002 and even the [2007] spill in Korean waters may have been avoided had the tankers been double-hulled," he said. The International Maritime Organisation (IMO), which oversees shipping safety and environmental performance, has mandated that new tankers over 5,000 deadweight-tons (dwt) be double-hulled from July 1993. "About 10,000 accidental oil tanker, combined carrier or barge spills have occurred since 1970." "Single-hulled tankers are being phased out," Santillo said, according to the International Convention for the Prevention of Pollution from Ships (MARPOL) Annex I. The EU also recently banned all single-hulled tankers carrying heavy grades of oil from entering European ports. "Phase-out dates range from 2005 to 2010. By 2010, therefore, . . .

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