JAPAN – Since 2006 the diesel electric contra rotating system produced by IHI Marine United of Tokyo have powered six marine vessels and the company have eight more on the order book. The considerable reductions these units achieve in fuel consumption and noxious carbon dioxide and nitrous oxide emissions are not the ultimate goal for the company, which has shipyards in Yokohama and Kure.
As detailed in our article earlier this month IHIMU have aspirations to construct a concept ferry using only electricity as a power source. Their system, known as a zero emission electric propulsion ship, or ZEEPS, will be an inland passenger ferry of around 250 tonnes. The proposed dimensions are length overall 30 metres, beam 12 metres and hull depth 3.6 metres. She will be powered by the familiar contra rotating propellers driven by 2 x 400kW motors. The power will come from banks of lithium-ion batteries which IMI are currently optimising to be suitable for the stressful task of powering a ship as opposed to a car.
An IMI spokesman said in a statement,
“Vessels need higher power and enormous capacity for propulsion compared to automobiles, and we have carried out parametric studies among wide range of existing vessels enabling us to develop the design concept IHIMU-ZEEPS applicable for plug-in operation.
“Efforts are being continued to investigate application of a huge capacity battery system for marine use and practicable control method for the ZEEPS, in close coordination with our government, relevant authorities and societies, in order to establish safety rules and regulations.”
The concept will also rely on the application of a safe and easy to operate shore based power source and connection system. IMI intend to use this vessel as a first stage in extending the companies range of all electric ships to larger new builds. The company currently builds all vessel types from patrol and work boats to cape size bulk carriers.
The picture is of their “super-fast” passenger car ferry Suzuran, which, at 29.4 knots service speed, is rated the fastest ferry exceeding 3000 metric dead weight tonnes in the world.
http://www.ihi.co.jp/ihimu/english/presidents.html
