Sometimes the wheel does not have to be reinvented, but it is enough to optimize already existing developments. This has been written for example by the Finnish company Norsepower on the flags. The company sells a so-called rotor sail. The fundamental theoretical work was provided by the flow researcher Ludwig Prandtl at the beginning of the last century. In turn, German engineer Anton Flettner developed the Flettner rotor named after him. It is a rotating cylinder that benefits from the so-called Magnus effect. Specifically, the motion of the cylinder deflects the airflow: on one side of the cylinder, the air is accelerated to create a vacuum, while on the other side, the slower air results in overpressure.
The wind direction in the Baltic Sea offers ideal conditions
The result of this Magnus effect is that a driving force is created transversely to the air flow. Because the wind usually comes from the west on the Baltic Sea, the rotor sail can thus be used particularly effectively for trips from north to south and back. Here again the ferry Copenhagen comes into play, which connects Rostock with the Danish island Falster. The ship belongs to the German-Danish ferry company Scandlines and already has a comparatively environmentally friendly hybrid drive. In the second quarter of next year, an additional rotor sail from Norsepower will be installed. The users of the ferry are likely to notice the change quite quickly. After all, it is a cylinder with a height of thirty meters and a diameter of five meters. A bit, therefore, the construction is reminiscent of a classic chimney.
The original invention was significantly further developed
Unlike this, the rotor sail does not emit any pollutants, but even improves the environmental and climate balance of the ferry. Because Scandlines assumes that the CO2 emissions can be reduced by four to five percent through the modern Flettner rotor. This does not sound like a lot, but at a daily use at the end of the year, but still results in a significant saving. The engineers at Norsepower also promise that they could implement important improvements over the classic models. Thus, the cylinder is now made of carbon and glass fibers, which on the one hand ensures safety and stability, on the other hand, but significantly reduces the weight. In addition, the rotor should now be easier to use and rotate faster than in the past. So far only three ships have actually been converted, but there are already more orders.
Further articles about trends in the field of ferries:
Revolution in shipping: An autonomous ferry is being tested on the Rhine
For 200 passengers: The world's largest electric ferry starts operations
Water-Go-Round: The construction of the first US hydrogen ferry has begun!
Premiere in Germany: First ferry with environmentally friendly natural gas drive
Technological breakthrough: Why a Norwegian hybrid ferry no longer needs a charging cable