NOVEMBER 11, 2011 — The two 3,600 TEU Jones Act containerships ordered by Matson at Aker Philadelphia Shipyard will have the largest dual-fuel engines ever ordered in terms of power output. Each ship's MAN B&W 7S90ME-GI engines will develop a massive 42,700 kW.
The engines and related systems will be manufactured by MAN Diesel Turbo's licensee, Hyundai, and will be able to use HFO, MDO or LNG as fuel.
MAN Diesel & Turbo says that the 7S90ME-GI uses the Diesel cycle to maintain high efficiency, with no need for any derating. The use of the Diesel operating principle means there will be negligible methane slip and no need for restrictive load ramps or other knock-preventing measures. MAN Diesel and Turbo view the order as yet another significant step in the adoption of its dual-fuel technology by the marine market.
"The ME-GI has a number of inherent characteristics that we feel give it a decided advantage in the market," says Ole Grøne, Senior Vice President Low-Speed Sales and Promotions, MAN Diesel & Turbo. "Primarily, it is a Diesel engine in contrast to the other dual- or triple-fuel engines on the market, which are Otto engines. Simply put, engines that operate according to the Diesel principle have a higher efficiency and power concentration than those following the Otto principle. Furthermore, in the light of after-treatment, a Diesel engine's performance can benefit from NOx control, both in regard to fuel and gas, and within both Tier II and Tier III areas."
Mr. Grøne notes that a high focus has been put on the safeness of MAN Diesel & Turbo's dual-fuel gas technology and says: "Due to compact, double-wall, gas-fuel pipes in the engine room and on the engine, the gas volume at any point in time within the engine is kept to a minimum, ensuring complete safety."
The ME-GI engine
The ME-GI engine is the culmination of many years' work. Depending on relative price and availability, as well as environmental considerations, the ME-GI engine gives shipowners and operators the option of using either HFO or gas – predominantly natural gas. An ME-LGI counterpart is being developed to use LPG and methanol.
Mitsui became the second MAN Diesel & Turbo two-stroke licensee to demonstrate the ME-GI concept after Hyundai did so in Korea in November 2012. Shortly afterwards, TOTE – another American shipping company – ordered two 8L70ME-GI engines to power two 3,100 TEU newbuilding container ships, with an option for three additional vessels. That announcement represented the first commercial order for the engine type, officially designated as ME-C-GI (M-type, Electronically Controlled, GI for Gas Injection) in the MAN Diesel & Turbo low-speed portfolio.
The following month, MAN Diesel & Turbo was able to confirm the successful introduction of the ME-GI to the market with the announcement of another order when Teekay LNG Partners L.P. (Teekay LNG) placed an order for two LNG carriers powered by 2 × 2 5G70ME-GI engines, including an option for three further ships. This order has now been increased to 4 vessels with 5 options.
MAN Diesel & Turbo sees significant opportunities arising for gas-fuelled tonnage as fuel prices rise and modern exhaust-emission limits tighten. Research indicates that the ME-GI engine delivers significant reductions in CO2, NOx and SOx emissions. As the ME-GI engine has no methane slip it is, says MAN Diesel & Turbo, "therefore the most environmentally friendly technology available."