FIRST ORDER FOR DOLPHIN PROPULSION SYSTEM
Seven Seas Voyager, the new 50,000gt cruiseliner under construction by T .Mariotti at its Genoa yard for delivery to Radisson Seven Seas in 2003, is among the first ships to be equipped with the new Dolphin podded propulsion system jointly developed by STN Atlas Marine Electronics of Hamburg and and John Crane-Lips of Drunen, the Netherlands.

The system's podded propulsors, due for delivery early next year, are designed to deliver 2 x 7000 kW at 170 rpm. Main features include integration of a powerful electric drive into a hydro-dynamically optimized pod below ship, resulting in a directly-driven propeller. Extensive CFD analyzes and model tank tests have led to the development of a pod shape with enhanced efficiency and maneuvering characteristics.

Based on John Crane-Lips’ established steerable thruster technology, Dolphin has been developed for power ranges extending from 3 MW to more than 19 MW and is suitable for a wide variety of vessels designed for high speed and good maneuverability operation. With a continuous rotation angle of 360° in the vertical axis, the pod ensures optimum maneuverability for commercial vessels as well as those engaged in offshore dynamic positioning.

The standard drive of the fixed-pitch propeller includes an air-cooled six-phase synchronous motor; gears, shaft systems, rudders and stern thrusters forming part of conventional electric drives are not required. The system’s shaft is protected within its casing by a combination of face and lip seals.
In addition to the Dolphin system, the scope of delivery by STN Atlas Marine Electronics and John Crane-Lips for Seven Seas Voyager also includes a complete propulsion system with synchro-converters, control and joystick system, diesel alternators, and a high-voltage distribution assembly with propulsion and mains transformers as well as bow thrusters.

PODS FOR ROPAX

Siemens-Schottel propulsor systems will be powering two new RoPax vessels ordered by the TT-Line shipping company and to be built by SSW Fähr- und Spezialschiffbau GmbH of Bremerhaven. The ships will be operating in the ferry service between Travemünde and Trelleborg. The Siemens Marine Engineering Subdivision in Hamburg will be supplying and installing all the electrical machinery and systems as a turn-key contract worth around $40 million.

Each of the 190 m ships will be propelled by two Siemens-Schottel SSP 10 Propulsors. The power output of each SSP 10 will be 11 MW. The turn-key project also includes all the automation equipment employing proven “SIMOS IMAC 55” equipment and the communications systems.

The SSP utilizes a compact permanent magnet electric motor that allows the pod to have a lower profile, permitting more efficient water flow into the propellers.

The SSP is particularly suitable for passenger vessels such as TT-Line’s two new RoPax ferries because its twin screws produce much lower noise and vibration levels so passengers can enjoy higher standards of comfort.

Since the Propulsor comes in sizes from 5,000 kW to 30,000 kW it is suitable for the whole range of outputs needed by seagoing vessels.
Further development of electric propulsion systems will undoubtedly be expanding the range of application of pod-type propulsion systems in the future .In the permanent-magnet electric motor and the twin propeller concept, the Siemens-Schottel Propulsor is employing two basic technologies that, since they are both innovative and trend-setting, provide a solid foundation for successful penetration of the market. ML

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