The new super long-stroke MAN B&W S90ME-C9 engine to be built in China
Seaspan Corporation has placed an order for 7 + 18 newbuildings of 10,000 teu container ships at Jiangsu YangZiJiang Shipbuilding. These will be powered by the new super long-stroke engine type MAN B&W 10S90ME-C9, which will be built by the Chinese engine builder CMD. Traditionally, MAN Diesel & Turbo K98-type engines have been used as prime movers by 8,000-10,000 teu capacity container vessels. Following efficiency optimisation trends in the market, where container ships have increasingly adopted lower ship speeds, the engine designer evaluated the possibility of using even larger propellers with a view to using engines with even lower speeds for propulsion.
Investigations revealed that container ships are indeed compatible with propellers with larger propeller diameters than current designs, and the high efficiencies that follow an adaptation of the aft-hull design to accommodate the larger propeller. The new, higher-powered, super long-stroke S90ME-C9 engine type meets this trend in the market. MAN Diesel & Turbo investigations indicate an overall efficiency increase of about 7% when using the S90ME-C9, compared with existing main engines, depending on the propeller diameter used.
Choice of engine
Canada based Seaspan Shipmanagement Ltd. entered a close dialogue with MAN Diesel & Turbo to decide upon main engines for its expanding fleet of newbuilding container ships. The owner initially considered the MAN B&W K98ME-C engine, but ultimately settled for the super long-stroke 10S90ME-C9 type on account of its superior fuel savings, a choice that required a redesign of the newbuildings’ aft-ship to accommodate the lower engine rpm and larger propeller diameter. The yard and its design partner changed the design accordingly.
Seaspan has previously built ships at YangZiJiang Shipbuilding with 6K80MC-C engines built by CMD in China.