Mitsubishi Heavy Industries Ltd. (MHI) has received an order for two next-generation LNG carriers from Mitsui & Co. Ltd. The carriers on order feature a design that achieves improvements in both LNG carrying capacity and fuel performance through the adoption of a more efficient hull structure and a hybrid propulsion system, according to a press release.

The vessels are scheduled for completion and delivery in 2018 and 2019, respectively. They will be put into service for the Cameron LNG Project underway in the U.S., an initiative in which Mitsui is participating. The event marks the first order placed to MHI for LNG carriers to transport shale gas.

The order for the two LNG carriers was received through MI LNG Co. Ltd., a joint venture between MHI and Imabari Shipbuilding Co. Ltd. The vessels will be constructed at MHI's Nagasaki Shipyard & Machinery Works. Specifications will be a length overall of 297.5 m (976 ft), width of 48.94 m (160.6 ft), depth of 27 m (88.6 ft) and draft of 11.5 m (37.7 ft). The carriers will have four apple-shaped tanks, an improved version of high-reliability Moss-type tanks designed with a bulging upper half. Total holding capacity of the tanks will be 177 Mcm (6.3 MMcf). LNG carrying efficiency has been increased as the vessel width has been kept to a size enabling its passage through the newly expanding Panama Canal expected to go into service early in 2016.

The LNG carriers on order feature a hybrid propulsion system dubbed STaGE (Steam Turbine and Gas Engines), which combines a steam turbine and engines that can be fired by gas. STaGE's components consist of the Ultra Steam Turbine plant (UST), a reheating steam-type marine turbine developed independently by MHI, a dual-fuel diesel engine capable of operating on both gas and oil, and an electric propulsion motor. Plant efficiency has been improved through the UST's effective use of the engine's waste heat, resulting in a propulsion system enabling high-efficiency navigation throughout a full range of speeds.