Hitachi Zosen-MAN B&W 12L50MC Mk6
In December 2000, Hitachi Zosen Diesel & Engineering Co., Ltd. completed the Hitachi Zosen-MAN B&W 12L50MC Mk6 diesel engine which was installed on the Ro / Ro vessel operating between Hokkaido and Yokohama. This engine contributes to keeping the cargo space of he ship flat to obtain the optimal height for engines in this class of low-speed engines although the engine length was increased because of the twelve cylinders.
To obtain more power, the mean effective pressure was increased by 1.80 MPa based on the results of the world's newly developed L50MC Mark 6 engine.
For maintaining reliability, he updated design developed for MC-C, i.e. High Topland Piston Crown, Constant Pressure Relief piston ring with additional height, shorter height piston skirt with copper band, calliper type thrust bearing, etc., were applied.
As special application for this project , Auxiliary Blowers were arranged to he improved type as applied for MC-C engine, and as countermeasure for low-load opera ion, the exhaust gas by-pass system was applied, which are effective in the opera ion of he low load, i.e. lower than 60%, to keep the combustion chamber in excellent condition by applying higher scavenging pressure at low load, but the high pressure was compensated by opening the by-pass valve automatically at the high load i.e. higher than 60%.
The Main engine was arranged by non-reversible type because of the Constant Pitch Propeller application and the MEP dependent system was applied to he cylinder lubricator o keep the appropriate level of lubrication in the case of constant engine speed.
PRINCIPAL PARTICULARS
Cylinder bore ... 500 mm
Piston stroke ... 1,620 mm
Cylinder pitch ... 890 mm
M.E.P. ... 1.80 MPa
Output at MCR ... 16,920 kW
Speed at MCR ... 148 min-1
