Surface drive
A surface drive is a boat or ship drive in which the propeller is only half submerged.
Since the propeller diameter can be selected to be larger, the efficiency increases (see propeller parameters ), which is why surface drives can usually be driven faster and more energy-efficiently than with conventional drives. In addition, the water resistance is significantly reduced because apart from the lower propeller blades, no parts of the drive are in the water, which in conventional drives makes up about 30% of the total water resistance.
Surface drives are often used in high-performance, fast speed , power or racing boats , although some larger yachts, ships and the solar catamaran Tûranor PlanetSolar also have surface drives. In the case of the Planetsolar, the drive has not proven itself for cruises in waves that are typical of the ocean. During maintenance work in early 2013, the drive was converted to a conventional, submerged drive with fixed 5-blade propellers and each with its own rudder. After the upgrade, the Planetsolar was able to beat its own record of 26 days for crossing the Atlantic by 4 days during its circumnavigation of the world.
Important manufacturers are ZF Friedrichshafen AG , Levi Drives Sdn Bhd from Malaysia or Arneson Industries, who were significantly involved in the development and offer a simple but innovatively designed drive.
The Arneson drive has an articulated propeller shaft that can either be adjusted vertically to trim the boat or horizontally to steer the boat like a sterndrive . In the latter case, the rudder blades clearly visible in the upper picture on the right are superfluous. Arneson drives are widely used in offshore racing .
Individual evidence
- ↑ Planetsea - Explanation of the disadvantages of the surface drive with photos of the new drive on the middle of the page. Retrieved August 10, 2014 .
- ↑ PlanetSolar - four days faster across the Atlantic. Retrieved August 10, 2014 .