MAN Diesel & Turbo’s PrimeServ division in Frederikshavn has, in close cooperation with shipowner and constructional engineering company NCC, performed a propulsion equipment upgrade for the ‘MV Baltic’, a 900 m³ sand and gravel dredger. A 14 % improvement in fuel efficiency has been reported following an exchange and modernization of the vessel’s propeller blades and propeller nozzle.
The vessel, which was built in 1983, had, during many years of operation, suffered from propeller and aft-ship vibrations resulting in high noise levels in the accommodation. Eventually the nozzle broke loose from the hull.
The propeller-blade design chosen was a medium-skew blade profile for ducted operation with a MAN Alpha AHT nozzle – customised with a length/diameter ratio of 0.5. The new nozzle and blades were installed in April 2012 while the vessel was docked at Svendborg Shipyard, Denmark. The ship has been in operation with the new propulsion equipment since April and the feedback from the Chief Engineer and the operational crew clearly indicates a much improved performance.
According to the company’s Chief Superintendent
- The measured fuel consumption reduction is 14%.
- The noise level in the accommodation is reduced by 10 dB.
- There has been an effective reduction of vibrations.
- The ship’s manoeuvrability in harbours has also been improved.
The financial aspect of the project has also proved very attractive for NCC with an estimated payback time of just 1½ years.
Source: MAN
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