(drawing from the article " Rowing Wheel "
" Military Encyclopedia of Sytin ")
Rowing wheel - a type of propulsion device used to propel ships [1] . It is a large wheel equipped with blades (plates) that are immersed in water [1] .
The rowing wheel is similar in design to a water wheel , with the only difference being that it is not water that sets the wheel in motion, but that the wheel is used for movement.
There are two main varieties of paddle wheels:
- - feed located behind the stern of the vessel . It can be either one wide wheel or two independent ones;
- - onboard, placed in pairs from the sides of the ship [1] . The outer enclosure of the side wheel casing is called a radiance, it often has a decorative design, the name of the vessel is usually indicated on it.
By design, wheels with moving and fixed blades are distinguished. The paddle wheel blades are called slabs and are often made of wood to facilitate repair. Wheel plates with fixed blades are installed stationary along the radius of the wheel on its spokes. With fixed blades, feed wheels are usually made. The movable plates are hinged and connected by rods to the eccentric , which allows the use of optimal angles of entry, abutment against water and the exit of the blades.
Due to the optimal revolutions of the reciprocating steam engine , the paddle wheels of the steamers do not require the use of gears, the engine drives the wheels directly. The use of propeller wheels on ships with an internal combustion engine requires the use of a reduction transmission - a gear reducer with a device for reversing (reverse gear), hydrostatic or electric transmission.
Content
History
Robert Fulton applied the original solution to the Demologos floating battery - he hid a 5-meter-diameter wheel between two half-hulls, thereby protecting it from artillery fire. The world's first steam warship developed an average speed of 5 knots , and a maximum speed of 7 knots , it was completed after the end of the Anglo-American war and after the death of its creator.
Later, already during the Civil War , the US federal government built conceptually very similar river battleships (see en: City-class ironclad ).
Propeller wheels driven by steam engines became the first propellers of self-propelled vessels and were widely used in the first half of the 19th century. Towards the end of the century, paddle wheels on the sea were almost completely replaced by more efficient propellers .
Weaknesses
- The main problem with the use of the propeller wheel is that with strong rolling on the side, the right and left propeller wheels alternately completely emerge from the water and, accordingly, plunge into the water too deep, the ship yawing , making normal movement impossible. Also, with strong excitement, the wheels are subjected to large dynamic loads, which disable them.
- Low efficiency - about 30% (the efficiency of the first successful propellers is up to 40%).
- More weight than the propeller and, consequently, a greater displacement of the vessel and fuel consumption.
- Great dependence on draft .
- The use of propeller wheels requires that traveling machines be placed above the waterline , which also reduces the available usable volumes, and in the navy it increases the vulnerability of the engine room.
- The side wheels require large rafts , increasing the dimensions of the vessel, reducing the useful deck area.
- Fodder wheels are less effective hydrodynamically, increasing the resistance of the hull, from under which they are pumping out water.
Benefits
- The stern propeller wheel in conditions of limited draft of the vessel creates an emphasis much greater than the propeller emphasis. [2]
- Side rowing wheels allow you to turn almost on the spot.
- Also, the propeller wheels provide more traction from a place, which is convenient for tugboats , and also allows them to have less draft. That is why in the USSR, the construction of river wheel tugs (but ships already with diesel engines ) continued until 1991 (pusher tugs of the BTK series [3] ). An example of a modern wheeled vessel is a passenger ship of the PKS-40 project (Sura type) equipped with stern propeller wheels.
Walking water bikes - catamarans are driven by a paddle wheel with a pedal drive .
See also
- Water wheel
- Ship propeller
- Propeller screw
- Jet propulsion
- Steam frigate
Notes
- ↑ 1 2 3 Rowing wheel // Military Encyclopedia : [in 18 vol.] / Ed. V.F. Novitsky [et al.]. - SPb. ; [ M. ]: Type. t-va I. D. Sytin , 1911-1915.
- ↑ SAGGER // ivki.ru
- ↑ Tugs BTK / BTK (1518, 1518A) (with propeller wheels with rotary blades on rotating rollers)
Literature
- M. Ya. Alfer'ev Ship Propulsion, ed. Water Transport 1938, p. 497
Links
- The return of wheeled steamers // seapeace.ru
- New features of the propeller wheel // wheelships.ru
- Rowing wheel - new projects // seatech.ru