Since the beginning in 1973, Oshima Shipyard, located in the very southwest corner of Japan, has produced close to 500 bulk carriers. In 1989 the yard decided to concentrate on bulk carriers only. This has paid off in terms of efficient production and innovation.

The yard produces some 30 vessels per year with a total workforce of only 1,000 permanent employees and some 700 subcontractors – making Oshima the most efficient yard in Japan in terms of tonnage produced annually per employee. The order book is comprised of 150 vessels, and contracts are now negotiated for 2012 and beyond. DNV has a long-standing excellent relation to Oshima, and 77 of the delivered vessels are to DNV class with 21 on order by the end of September 2007. We are very well received and taken care of by Mr Tatsuaki Hori, Senior Executive Managing Director, Dr Shinji Nonaka, Director, Vice Yard General Manager, General Manager of Design Department, as well as Mr Shigehiro Mori, Acting General Manager of Design Department.
Innovation in bulk carrier design is a key element to Oshima operations. The number of repeat customers among international shipowners and operators is proof that the specialisation of the yard on bulk is most successful. As we arrived by passenger high-speed ferry to the yard from the nearby town of Sasebo in pouring rain, we could see the close-to-delivery bulk carriers with an innovative bow design. Oshima has no less than three major bulk carrier design elements that were described to improve performance, reduce fuel consumption and consequently have an overall positive environmental impact. The three design elements – Seaworthy Bow, High-Lift Rudder, and Flipper Fins – are described in the following.

Seaworthy Bow
The new bow design gives the vessel on the average five per cent less fuel consumption in North Atlantic trade. The speed loss when heading into the waves is reduced. “I believe this bow will soon be the standard on all Oshima built vessels,” says Hori.

High-Lift Rudder
The new rudder design (see illustration below) improves bulk carrier manoeuvrability compared to a conventional rudder. There is higher lift coefficient and higher drag coefficient when steering. The maximum helm angle can be taken up to 45 degrees.

Flipper Fins
The bilge fin (see illustrations below) deflects bilge vortex to get wake gain and accelerate the flow near the top of propeller to reduce propeller-hull interaction. The aft-end fin is added for rectifying the flow around the centre of propeller to reduce resistance. The effect of the flipper fins is some four per cent less fuel consumed.
When discussing the overall future trends in bulk carrier demand, Hori says, “I think handymaxes will split into the segments between length overall less than 190 metres and those between 190 and 200 metres. The overall ship economy and life-cycle-costs together with the upsizing of ships would be key factors of optimum choice to maintain a competitive edge. One of our best solutions for that trend is ‘OS Max 60’ with 200m L over all. Its dwt exceeds 60,000 mt at shallow draft of 12.8m complying with Common Structural Rule. Its fuel oil consumption is lower than that of current 55,000 dwt type design.
“Currently new building business are talked for delivery four or five years ahead and shipowners are beginning to show an interest in new ship designs with the completion of the new Panama Canal some eight years from now. In addition, when it comes to coal carriers, I am confident that Oshima is the most experienced shipyard in this field through the construction of many carriers ranging from 80,000 dwt to 105,000 dwt with shallow draft. In the case of bulk carriers, because of a gap between the dwt with maximum canal dimensions and the freight lots to pass the Panama Canal, the ship type is not likely to be integrated into one type just like the current Panamax bulk carrier. I think we will be able to come up with solutions considering all factors, including port constraints such as ship length, width, draft, cargo handling shore equipment and operation for non-Panama Canal routes,” says Hori.
“We have prepared the line-up not only for coal carriers but also Post Panamax standard bulk carriers (so called ‘Baby Cape BC’) designed with Ore Alternate hold Loading modified from above mentioned coal carriers and a new design of 120,000 dwt type OS Max-120. We will make flexible response considering market needs.
“Increasing demand for half products trade such as the forest products besides bulk cargoes is our primary concern. This will lead to increased demand for box type hold bulk carriers with widened hatches and gantry or jib cranes as well as bulk carriers with TST and Hoppers. Oshima has come out ahead in the world in this field in terms of performance, experience and technology, and we have developed the design for the world’s largest 71k-dwt open-hatch bulk carrier,” says Hori.
We ask him about challenges and trends in cargo handling gear and equipment. “Our most concern is paid to manufacturers to keep stable and sufficient supply to meet with recent rapidly increased demand of bulk carriers. From this standpoint, I think we need to strengthen our ties with manufacturers,” he says.
”Oshima is now enhancing to operate factories at higher speed than ever,” says Hori, noting that Oshima is making a 49,000 square metres landfill at the centre of the shipyard using soil from an adjacent mountain. The landfill will become a new site for block storage and a new grand assembly and the third mooring berth will be constructed here. A 1200t Goliath crane will be installed by next June, in addition to the existing two sets of 300t cranes, to enlarge the extent of grand assemble blocks and to improve dock performance. “We will strive to focus on our challenges, to prepare for shipbuilding demand increase and attain the ultimate possibility of shipbuilding capacity in Oshima,” says Hori.

Date: 04 February 2008