Monohakobi Technology Institute (MTI; head office: Chiyoda-ku, Tokyo; president: Yutaka Yasunaga) and Nabtesco Corporation (headquarters: Minato-ku, Tokyo; President & CEO: Kazuyuki Matsumoto), have developed a new control device, called a governor*, that is expected to be effective in fuel savings and in reducing the burden on the main engine.

Development Background

Conventional governors frequently adjust the fuel injection volume to maintain consistency in the number of rotations of the main engine. They do this by detecting differences in the actual number of rotations of the engine from the number set up initially. They thus stabilize the speed of the vessel in constantly changing seas. During fuel injection adjustments, however, propeller rotations also change. Consequently, excessive amounts of fuel are supplied and used. In other words, conventional governors cause an effect similar to stepping too hard on the gas pedal of an automobile.

Features of New Governor Control Method

By slowing down the movements when they adjust fuel injection, the new governors control excessive fuel consumption, compared with conventional governors. Over the course of a year, fuel savings are 0.5% to 2%, compared with conventional governors. Moreover, the more rough the seas, the greater the fuel savings.

For the Future

The patent application has been filed, and the new governor control method will be implemented in NYK's seven 6,500-TEU container vessels and in two automobile carriers. NYK will further enhance the usability of the new governor control method by comparing the fuel savings among those nine ships, and by other means. From spring 2008, NYK will expand the number of vessels utilizing the new method.

*Governor A device that adjusts the fuel injection volume in the main engine's cylinder. When there is fluctuation in the number of rotations of the main engine's propeller, due to ocean wave disturbance, for example, the device adjusts the volume of fuel injected to maintain consistent rotation of the propeller and therefore the ship's speed.