Advanced trawlers will have MAN propulsion packages
Written by Nick BlenkeyOCTOBER 1, 2014 — Two series of fishing vessel newbuildings ordered by Icelandic owners will have MAN six-cylinder L27/38 main engines, but differ in the specified propeller, aft-ship and propeller-nozzle configurations. The general propulsion management and control system specified for both trawler designs is MAN Diesel & Turbo’s new, advanced Alphatronic 3000 generation. The installations will be configured for complete control-station set-ups at the vessels’ main bridges, starboard bridge wings, aft bridges and engine-control rooms.
Owner HB Grandi has ordered three 55 m vessels with a distinctive bow. Designed by Nautic ehf, they will be built in Turkey by Celiktrans Shipbuilding Co. Ltd.
Owners Vinnslustodin hf and Hradfrystihusid Gunnvör have each ordered one 50.7 m vessel built to a design by another Icelandic specialist fishing-vessel consultants and designer, Skipasýn. Both vessels will be built in China by Huanghai Shipbuilding Co. Ltd.
The Nautic vessels for HB Grandi will be propelled by four-bladed, 3.8-m MAN Alpha CP propellers, while the Skipasýn vessels will have larger, slower-running 4.7-m, three-bladed versions for a calculated bollard pull above 50 tons.
“We have been representing MAN Diesel & Turbo for more than 20 years as sales and service agents in the Icelandic market and now we are very pleased again to see increasing activities and investments after the financial crisis and following tough years for Iceland,” said Styrmir Petersen, Afltækni ehf, Reykjavik. “Additionally, it is of course both interesting and challenging for us that we will supply new MAN products and services to two state-of-the-art, Icelandic, fresh-fish trawler designs.”
In the Skipasýn designed vessels, the fuel-saving focus has been on the deployment of a large, efficient, 4.7-m propeller. As a result, the 800 r/min engine (MCR) speed has had to be geared down to an optimal propeller speed of just 89 r/min. Blade-number optimization resulted in a three-bladed configuration. At the 2,040 kW operating point, the three-bladed MAN Alpha VBS1020 propeller – using the Alpha High Thrust nozzle – is calculated to deliver a bollard pull above 50 tons.
The three Nautic-designed, 55-m vessels for HB Grandi will use the same MAN six-cylinder L27/38 engine, but will have four-bladed, ducted MAN Alpha VBS 860 propellers. A key Alphatronic 3000 control-system feature will be the tailored “dual-propeller load curves” for optimizing towing/trawling and free-sailing conditions.
The specified, floating-frequency concept for both trawler series increases the flexibility and economical part-load pattern. The propulsion system is able to operate in “shaft-alternator mode” with reduced engine and propeller speed (within the corresponding 50 to 60 Hz speed envelope). With this part-load optimization feature offering up to 17% lower engine/propeller speed, fuel consumption is accordingly reduced. The L27/38 engines have optimum load and low-speed characteristics for floating frequency: high torque and approx. 50% power is available at speeds reduced from the 60 Hz load point to 50 Hz.
Owner HB Grandi has ordered a Nautic designed vessel (above) with MAN Alpha’s 4-bladed CPP plant (below)
Vinnslustodin hf and Hradfrystihusid Gunnvör have each ordered one 50.7 m vessel to a Skipasýn design (above) that will have MAN Alpha’s 3-bladed CPP plant (below)
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