Japan studies ways to prevent tanker spills

July 16, 1997 The Japanese Ministry of Transport has called on domestic shipowners to study and report on wide-ranging safety measures to prevent oil spill by tankers, including promoting double-hull structures for carriers. The Japanese Shipowners' Association agreed to tackle the topic and has organised a top-level conference on July 23 to kick off the project. This comes on the heels of a 1,500-ton crude oil spill into the Tokyo Bay from the carrier Diamond Grace.
The Marine Accidents Inquiry Agency has yet to complete their final analysis of the accident, but it is possible if the Nippon Yusen KK owned ship had been fitted with double sides and double bottom, the spill may have been prevented. The tanker most probably hit the rocky sea floor, and a double-hull is designed to reduce the impact of ruptures by spacing the inner and outer hulls 3 meters apart.
The International Maritime Organisation, under the International Convention for the Prevention of Pollution from Ships (MARPOL), requires that crude tankers delivered in July 1996 and after be refitted with double sides and double bottoms. The organisation has also proposed that single-hull carriers older than 25 years be taken out of service. But this still leaves a big gap, as evidenced by the Diamond Grace, a single-hull carrier with less than 25 years of service.
There is another issue which must be addressed. Even if Japan adopts stricter regulations, enforcement will be difficult since the legal web surrounding ownership, operator, leasing contract and registration span different countries. Of some 2,000 carriers counted among the domestic commercial fleet, only 191 operate under the Japanese flag.