MHI delivers “super eco ship”

The 5,681 tonne vessel, which measures 118m and has a service speed of 19 knots per hour, features a high efficiency propulsion system, which MHI says enables it to achieve substantial energy savings, environmental load reduction and enhanced passenger comfort and safety.

It employs a tandem-hybrid contra-rotating propeller (CRP) propulsion system developed by MHI. It comprises single-shaft propulsion propellers that enable the direction of propulsion power to be freely changed.

In comparison to conventional twin-shaft systems, MHI says the new system enables less appendages for propulsion systems such as skegs, shaft brackets, and rudders and reduces water resistance, and improves energy-saving efficiency by allowing the use of only fuel-efficient low-speed diesel power in bays and channels where slower navigation speeds are required.

Thanks to this, the Tachibana-Maru can achieve 15.6% higher fuel efficiency than the Salvia-Maru, a cargo passenger ship built by MHI and currently in service at Tokai Kisen.

In addition, the use of an electronically-controlled fuel injection system enables the main low-speed marine diesel engine to achieve higher combustion efficiency, thereby ensuring that the Tachibana-Maru emits less CO2 and NOx.

The vessel will be put into service on the route between Tokyo and the Izu Islands later this month.