Box ship operator decides to derate

SEPTEMBER 3, 2014 — Operators of large container vessels continue to turn to slow steaming to gain fuel saving. In line with this trend, Mitsui Engineering & Shipbuilding Co., Ltd. and its 100% owned subsidiary MES Technoservice Co., Ltd have received an order from a Taiwan shipowner to make fuel-efficiency modifications to the Mitsui-MAN B&W 12K98MC/M6 main engines of three large containerships.

The modifications to be carried out — or “derating” — involves reducing the MCO output by modifying the main engine and turbocharger. The modification will increase the cylinder P.max as well as the mean effective pressure, thereby increasing combustion efficiency. This results in a significant reduction in fuel consumption that is even greater than that gained from the turbo-charger cut out that has been applied to several large type container vessels in recent years.

Depending on the vessel operation patterns, the expected payback period for the modification work is one-two year.

The modification work is to be carried out later this year.