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Best practice in ship propulsion
Amartech made a system that adjusts the ship's propeller blades, moving the ship forward and backward without changing the shaft's direction of rotation.
The Monaco Yacht Show is a boat show for the extremely rich and famous on earth. At the annual four-day event in September the world’s most expensive mega yachts are exhibited. It is also a meeting place for the representatives of the Dutch wharfs. They belong to the world league and often provide innovations in the technical field with respect to furnishing and driving of mega yachts.
Hein Eek from Amartech B.V. was there too. The company specializes in propulsion and rudder systems for ships, often splendid sail and motor yachts. It’s an autonomous part of the renowned Balk Shipyard in Urk.
Amartech developed an ingenious system, with which a ship’s propeller blades can be adjusted. Meanwhile the system has been applied successfully in the Lunar C115, a super sail yacht of 35,3 meters built by Conrad Shipyard in Poland. The yacht catches the eye because of its robust, but graceful line. It has recently been nominated for The World Superyacht Awards 2014.
Electrical solution
Hein Eek: “By adjusting propeller blades we can make the ship move forward and backward without changing the direction of rotation of the propeller shaft. Also the sailing speed can be controlled by it, so that the engine can run at the ideal speed, thus producing the best output. The propeller can also be feathered, so that the ship does not encounter any resistance during the sailing. A system like this existed, provided with an hydraulic drive, but it cannot always be applied. That’s why we were looking for an electrical solution. Our system is unique as it is able to absorb the thrust of the ship, as a result of which the thrust bearing can be left out. Moreover, because of the small mounting length, it is also a very compact system, leaving more room for living.”
In this Amartech system SEW technology is built in, like an SEW-CMP63 servo motor and an SEW MOVIDRIVE® MDX61B servo inverter per propeller. Because of this, the construction and start-up of such a beautiful ship is a unique project for our company as well.
How does the system work? The throttle lever data and a linear transducer that corresponds with the position of the ship’s propeller, are collected by a PLC. The PLC controls the servo motor and inverter, and the speed of the main engine. When the propeller blades are in position, the brake is activated in order to avoid drifting. An absolute Hiperface encoder is mounted on the servomotor. It gives feedback to the PLC via the MODBus TCP about the position. Upon start-up the propeller is boosted forward and backward at full speed and the encoder’s position is saved in the PLC (and as a software limit in the inverter).
Meanwhile the Lunar has passed all tests at sea successfully and the captain is wildly enthusiastic about the operation system. Therefore it would be nice, both for Amartech and SEW-Eurodrive, if the yacht captures The World Superyacht Awards 2014.
