Japanese concept for zero-emission ferry

Following the success of previous small vessels using diesel-electric propulsion and contra-rotating propellers, IHI Marine United (IHIMU) of Tokyo, whose experience includes building a VLCC with a contra rotating drive during the 1990s, is now planning to construct a concept ferry using only electricity as a power source. To be known as the Zero Emission Electric Propulsion Ship (ZEEPS), this will be an inland passenger ferry.

Since 2006 the diesel-electric contra rotating system has been installed on five small tankers and a bulk carrier, and eight more are on order. While the reduction in fuel consumption and exhaust gas emissions achieved by these units is considerable, the company, which has its main shipyards in Yokohama and Kure, is committed to building vessels that impact even less on the environment.

“Ships need higher power and enormous capacity for propulsion compared to other applications,” says an IHIMU spokesman. “We have carried out parametric studies among a wide range of existing vessels that have enabled us to develop the design concept, IHIMU-ZEEPS, which is applicable for plug-in operation.”

The ZEEPS prototype vessel is expected to have an overall length of 30m and a beam of 12m. The contra rotating propellers will be driven by two 400kW motors powered by banks of lithium-ion batteries which the company is currently optimising for marine application.

“Efforts are continuing to investigate the application of a large battery system for marine use and a practicable control method for the ZEEPS. We are collaborating with our government, relevant authorities and classification societies in order to establish safety rules and regulations,” comments IHIMU.

The concept will utilise the application of a safe and easy-to-operate shore based power source and connection system. The company currently builds a wide range of vessel types, from patrol and workboats to Capesize bulk carriers and large tankers, and intends to use this new vessel as a first stage in extending its range of all-electric ships to larger newbuilds. PST