Research Winches for R/V Maria S. Merian
Seven special winches were supplied by Hatlapa in December 2003 after being tested and demonstrated in the factory. These winches are intended for the new research vessel Maria S. Merian, which will support the vessel Polarstern during operations in the Arctic.
Hatlapa has escorted this project for five years, during which time the design of the winches was formed in close cooperation with the order principal BAW (Bundesanstalt fur Wasserbau) and the shipyard Krogerwerft in Rendsburg.
One specialty is the combination of friction and storage winch for handling the very long and relatively thin measuring cables. The advantage is that the sensitive and expensive research ropes can be spooled on the storage winch free from load. The pull is created in the friction part and exerted via several grooved drums to protect the rope. A spooling device which has been developed and patented by Hatlapa also guarantees that the rope is wound onto the storage winch in a clean and gentle manner. Thereby the crossing of rope layers resulting in rope breakages are avoided. The storage winches have a very large drum diameter for realizing low bending radii of rope when wound on for protecting the sensitive measuring wires in the ropes.
As already mentioned, the ropes are not just normal synthetic or steel wire rope, but consist of a single cable with an outer coating of synthetic material to protect the conductor against damage, to guarantee the necessary shielding, and to absorb the forces. Constant communication is possible between the control and measuring instruments by transmission rings in the winch, also during paying-out and hauling-in the rope. Furthermore, lighting conductor cables are in use which have a similar structure, allowing also constant communication between the control and measuring instruments.
By using frequency inverter controlled motors the speed can be infinitely variably controlled and the winches operated absolutely synchronously. The otherwise usual maximum demands on the shipboard power supply, the ropes and mechanics are eliminated, because the winches are on standby from zero speed to full torque, thus allowing a smooth start. The electric driving capacity of each winch is up to 352 kW that is produced by four motors of each 88 kW. By using four motors capacity reserves are increased on the one hand, and on the other hand the distribution of the load into the gear allows a compact construction. To dissipate the heat arising in the electric motors water cooling has been provided, contrary to the usual air cooling.