The main engine of one of Seaspan’s 8,500-TEU ships under construction by Samsung Heavy Industries in South Korea. The MAN B&W 12-cylinder engine will generate 93,120 hp.
The orders for these giants come on top of an already ambitious building program that has vaulted Seaspan into the major leagues of containership owners.
The company, based in North Vancouver, British Columbia, has ordered eight 9,600-TEU ships for delivery in 2006 and 2007. It also has on order five 4,250-TEU ships for delivery in 2005 and five 8,500-TEU ships for delivery in 2004. The ships are being built at Samsung Heavy Industries in Korea for Seaspan and its partners China Shipping Container Lines and Danaos Shipping of Greece.
The vessels will join five 4,250-TEU ships that Seaspan took in 2002. All of these ships will go under charter to China Shipping Container Lines.
Seaspan also has on order nine 4,250-TEU ships for delivery in 2006 and 2007 with charter arrangements in place for CP Ships.
The magnitude of this building program puts Seaspan in a unique position to assess just how large containerships may get.
“One of the main limiting factors in building containerships over 10,000 TEUs is in the thickness of the steel plate and the existing welding techniques,” said Graham Porter, Seaspan’s director.
“We have great confidence in the people at Samsung Heavy Industries in Korea. Of their approximately 10,000 employees, something like 2,000 are engineers or naval architects. Their engineering and design capabilities are superb,” Porter said.
Recognized as world leaders in the building of containerships, there is little doubt that when ships with larger than 10,000-TEU capacities are built, they will be built in Korea. But as Porter explained, they will be built with significantly different technologies. The 9,600-TEU ships currently on order have grown within the same technological envelope as that developed for the 8,500-TEU ships.
“With some more tweaking of the design, we could take it to 10,000, but that will be the limit of the current 90-mm hull plating and engine sizes,” he said. “To go larger than that would require heavier framing and plate, which by weight alone, would cancel out the increased cargo capacity.”
| Image Credit: Photos courtesy Seaspan Ship Management Ltd.  The same engine will be used in Seaspan’s 9,600-TEU vessels. A section of an 8,500-class vessel is lowered into place. |
Porter sees a continuing role for the 4,250-TEU ships in dedicated runs between smaller ports such as Pusan, South Korea, to Vancouver, British Columbia. They can also transit the Panama Canal to take cargo from Asia by the all-water route to the U.S. East Coast. He calls these the 737s of the shipping industry, in reference to that workhorse of the airline feeder routes.
For a lot of shipping lines that took delivery of larger panamax 5,500-TEU ships in the late 1990s, the problem will be that these ships have large capital costs that will continue to bear on unit shipping costs.
Seaspan expects the new ships to deliver significant economies of scale that will enhance their efficiency and profitability.
“The capital cost of our 8,500-TEUs are about $80 million each, whereas a 5,500 ordered in the late 1990s would have a similar cost of about $70 million. That means that the larger vessels can take on a short cargo for a back haul across the Pacific to Asia and transport it with no loss. They are then in position to take full loads from Asia to America at competitive prices while maintaining profitability.
With most major ports installing container cranes that will reach to 20 or even 22 containers stowed across a ship, the beam stacking of containers is not an issue. A 4,200-TEU ship has a length of 852 feet and a beam of 106 feet with 14 rows of containers across. The 8,500-TEU ships have a length of 1,095.5 feet and a beam of 140 feet, supporting 17 rows of containers across. The 9,600-TEU ships will be just slightly longer at 1,105 feet, but their beam will be increased to 195.5 feet, permitting them to take 18 rows of containers across.
Porter understands that the design of the big ships will allow them to be lengthened by 80 feet, while still accommodating the resulting torsional forces. These longer ships will be able to take two more container bays, bringing their total capacity to about 10,200 TEUs.
These ships are the 747-400s of the marine world, taking on huge cargoes between ports such as Shanghai and Long Beach, Calif., or East Asia and northern Europe. The efficiencies of the larger ships will allow them to compete effectively on the heavier-volume cargo routes.
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Both the 8,500- and 9,600-TEU ships will use the same MAN B&W 12-cylinder 93,120-hp main engines, but the extra beam will cost the larger ship about 1 knot of the 25.2-knot speed of the 8,500-TEU ships. Both the larger vessels will have single 3,000-kw bow thrusters. The 4,250-TEU ships use MAN B&W 8-cylinder 49,680-hp engines and single 1,600-kw bow thrusters.
Porter says that the growth in ship size involves two related factors — the hull form and the propulsion package. Some authorities predict that twin-engine configurations will be required to drive containerships larger than 10,000 TEUs. It is such thinking that holds Seaspan back from committing to those ships.
“We felt safe with the hull designs at 9,600 TEUs, and we could use the same proven engine, but going up in engine size from that brings on some less proven technology and greater potential problems,” Porter said.
Alan Haig-Brown
