motorboat
A motorboat is a watercraft powered by one or more internal combustion engines or electric motors . It can be used on both inland and coastal waters . To drive motor boats in Germany with an output of more than 11.03 kW (15 HP) on the propeller shaft, a driver's license is required - for sport boats usually at least a sport boat driver's license . A driver's license is required on the Rhine and Lake Constance from 5 HP.
history
The first motor boats were built in Germany and France. In 1865, Étienne Lenoir carried out test drives with a motorboat on the Seine . The motorboat was only put to sustainable use later by Gottlieb Daimler . 1886 with a gas engine working according to the Otto engine principle according to patent no. 39367 from Daimler. In August 1886, the boat took test drives with Daimler and Wilhelm Maybach on the Neckar . The first public presentation of a motorboat on the Waldsee near Cannstatt took place at the end of 1886 . In 1888 Daimler gave the German Chancellor Otto von Bismarck such a motorboat, which was baptized in the name of Bismarck's daughter Marie . Bismarck is said to have used the castle pond in Friedrichsruh . The von Bismarck family gave it back to Daimler-Benz in 1922; today it is an exhibit in the Mercedes Museum in Stuttgart-Bad Cannstatt . In 1898 the inventor Herman FL Linden developed the Autonaut , completely independently of Peter Beckmann, the scooter boat , both equipped with a drive that converted part of the kinetic energy of the orbital movement of the surrounding water into a forward movement. At the Summer Olympics in London in 1908 , motor boating was an Olympic discipline.
use
Motor boats that are used for recreational purposes and can be inhabited are called motor yachts . There are particularly powerfully motorized motor boats that are used, for example, to pull water skiers or for sporty offshore trips ( racing boats ).
Rarely are research vessels in boat size, for. B. the Mercator .
In the military sector, motor boats are referred to as M-boats ( V-boats for traffic boats in the Navy ). The purposes of the boats transported by truck are:
- Maneuvering ferries and floating bridges or parts thereof (military pioneering)
- Rescue and recovery of people
- Relocation of personnel and material on inland waterways or in flood areas
Boat types
Depending on the construction feature or type of engine, a distinction is made between the following types of motor boats:
- Sport boat with inboard or outboard engine
- Autoboat
- Day cruiser
- Half cabin
- Racing boat
- Cabin boat (middle cabin boat, front cabin boat)
- Motor yacht
- dinghy
- Chugboat
Construction principles
There are two basic design principles: displacer and glider . A displacer displaces the amount of water that corresponds to its own weight (static buoyancy) and always remains behind its bow wave. Due to its hull shape and drive power, a glider is able to leave the bow wave behind and then displace less water (dynamic buoyancy) than it corresponds to its weight. As a result, a planing boat also causes less wave action and “glides” over the water.
Every ship has a hull speed that can be calculated based on the length of the waterline. The formula is: Root of the waterline length in meters × 4.5 = speed in km / h. Examples: 4 m length (canoe, small electric boat): 9 km / h; 36 m (luxury motor yacht): 27 km / h hull speed.
Both types of construction have advantages and disadvantages. A displacer can reach its maximum speed (also hull speed) with a relatively low motorization and is more economical in consumption. It also runs smoother than a planing boat. A planing boat, on the other hand, can reach several times its hull speed. However, a glider has the disadvantage that it hits too hard in rough water and may therefore not be extended at all.
As a rule of thumb, only boats under 22 kg / kW (16 kg / HP) power-to-weight ratio can glide.
Half-gliders are also known as a mixed form. These boats are designed to glide, but due to their weight, they can only be planed with difficulty - they are usually between 22 and 41 kg / kW (16 to 30 kg / HP). Since a noticeable dynamic pressure builds up under their bottom, which lifts the boat a little out of the water and thereby reduces the resistance, they run a little faster than the hull speed.
Almost all fast motor cruisers over 9 meters in length are designed as semi-planers. From a length of 18 meters, the boats are mainly built as displacers.
Hydrofoils , whether motorized or powered by muscle power (leg kick or pedal drive), behave differently when they are in motion.
Soil shapes
Depending on the type of boat, one of the following hull shapes is used in the construction:
- Deep V bottom; characteristic by a V-shape extending to the stern. Typical for seaworthy cabin boats. Runs smoothly in rough water, but because of the larger floor area, they can only be brought into planing with more powerful engines.
- Moderate V-Bottom; runs fairly flat to the stern and is mainly used for outboard boats. Slides easily, but runs harder in rough water.
- Round frame bottom; With this hull shape, a boat does not start planing, but reaches its hull or maximum speed with a relatively weak engine. Round-frame floor is a typical floor shape for all displacers.
See also
Individual evidence
- ↑ Hans-Jürgen Reuß: Automobile and motor ship have the same roots . In: Hansa , Heft 2/2011, pp. 20-21, Schiffahrts-Verlag Hansa, Hamburg 2011, ISSN 0017-7504
- ^ Motorboat Marie (1888) at Traumarchiv.de
- ↑ Schult, Joachim: From the youth of the motor boat . Verlag Delius, Klasing + Co., Bielefeld, Berlin 1971, ISBN 3-7688-0129-2 (pp. 44-45).
literature
- SBF inland
- Heinz Overschmidt, Ramon Gliewe: Sport boat license inland engine. Delius-Klasing, Bielefeld 2004 (11th edition ) ISBN 3-7688-0658-8 (with official exam questions)
