The three new ships are part of a Qatargas package of 45 LNG carriers with MAN B&W two-stroke prime movers
Three of the world’s largest LNG-carriers successfully tested their propulsion packages at the end of last month. Each vessel is powered by two 6S70ME-C electronically controlled, two-stroke, lowspeed diesel engines, and this event marks a first for MAN Diesel in the LNG sector. The engines will operate on HFO. The vessels are part of a Qatargas project that comprises an impressive 45 vessels, each fitted with two MAN B&W low-speed prime movers, making for a grand total of 90 electronically controlled two-stroke engines. Of these, 31 QFlex carriers will receive two MAN B&W 6S70ME-C engines, each developing 18,660 kW, while the 14 larger QMax carriers will employ two MAN B&W 7S70ME-C engines, each rated at 21,770 kW at 91 rpm.
The three ships in question have been delivered from three different shipyards. The “Al Ruwais
” comes from Daewoo Shipbuilding and Marine Engineering and is owned by German PRONAV. The “Ternbek” is from Samsung Heavy Industries and is owned by the U.S. Overseas Shipholding Group
. The third, the “Al Gattara”, is also owned by the Overseas Shipholding Group and built by Hyundai Heavy Industries
. Doosan Engine Co. Ltd built the engines for the Daewoo and Samsung-built vessels, while HHI-EMD built the engines for the Hyundai-built vessel.
The vessels have also been fitted with four MAN Diesel 9L32/40 gensets each. STX Corporation built those for the DSME and Samsung vessels, while those on the Hyundai vessel were built by Hyundai itself.
The HFO-fuelled, ME-C engines chosen to propel the 45 ships comprise a part of the MAN B&W two-stroke engine programme that also includes a range of dual-fuel ME-GI engines. The GI-system, comprising a high-pressure injection system of natural gas, has proved commercially viable since 1994 when a 12K80MC-GI engine was employed by a Japanese power plant. Conversion to dualfuel operation, in the form of ME-GI, is an option currently being discussed for both the Qatargas and other LNGcarrier projects.
The ME-GI system is offered in a package based on Burckhardt compressors with a fully integrated tankpressure and gas-flow control system. The ME-GI range of low-speed, dual-fuel engines complements MAN Diesel’s engine programme that also includes the 51/60DF dualfuel, medium-speed engine, which is targeted at smaller LNG carriers in an electric-propulsion configuration.