Japan Marine United (JMU) is claiming 16% fuel savings from its contra rotating propeller (CRP) combined with other energy saving devices, and is looking to extend coverage to all vessel types.
JMU is the first shipbuilder in the world to fit a CRP to a large type bulk carrier, the 97,000 dwt Shoyoh.
The CRP comprises two fixed propellers that contra rotate. Takuro Yoshikawa, general manager of JMU Europe, explained that with a standard single propeller there is a stream of lost energy, with the CRP this is received by the contra propeller and converted into thrust.
Yoshikawa told the Japan Posidonia 2014 Seminar it was a tried and tested technology, which the shipbuilder has fitted 20 vessels without any problems.
JMU said that on its own the CRP produces fuel consumption savings of 7 – 10%. The percentage of fuel savings is based on comparisons with JMU’s standard single propeller design.
On the 97,000 dwt bulk carrier design it is combined with a crown duct and exhaust gas power generator which Yoshikawa said gives 16% fuel savings based on design conditions.
Yoshikawa said the cost was higher than some energy saving devices and there some changes to the hull form to accommodate the extra space between the rudder and propeller and the engine room arrangement for CRP gear.
“We are thinking to expand coverage to every type of vessel in the future,” he said.
Source: http://www.seatrade-global.com/
