 An old tram with a bow collector built in 1907 still running in Oberbozen, South Tyrol, Italy A bow collector is one of the three main devices used on tramcars to transfer electric current from the wires above to the tram below, the other devices being the pantograph and trolley pole. While once very common in continetal Europe, it has now been largely replaced by the pantograph. Download high resolution version (1002x1196, 172 KB)A old train still running on a mountain in 1250 metres hight in Oberbozen-Soprabolzano, South Tyrol, image taken by Fantasy on the 13. ...
Download high resolution version (1002x1196, 172 KB)A old train still running on a mountain in 1250 metres hight in Oberbozen-Soprabolzano, South Tyrol, image taken by Fantasy on the 13. ...
South Tyrol (Italian: Alto Adige, German: Südtirol; official in Italian: Provincia Autonoma di Bolzano-Alto Adige, official in German: Autonome Provinz Bozen-Südtirol) is an autonomous province of Italy that belongs to the region of Trentino-Alto Adige, of which it is a subdivision. ...
Jump to: navigation, search A modern tram in the Töölö district of Helsinki, Finland Volkswagen Cargo-Tram in Dresden. ...
In electricity, current is the rate of flow of charges, usually through a metal wire or some other electrical conductor. ...
The Z-shaped pantograph of the electrical pickup on German light railway. ...
Trolley poles are usually tapered cylindrical poles of wood or metal, used to transfer electricity from a live overhead wire to the control and propulsion equipment of a trolley car, tram or trolley bus. ...
World map showing Europe (geographically) When considered a continent, Europe is the worlds second-smallest continent in terms of area, with an area of 10,600,000 km² (4,140,625 square miles), making it larger than Australia only. ...
Origins
When the bow collector was first concieved by German inventor Ernst Werner von Siemens in the late 1880s, American inventor Frank J. Sprague of Virginia had just patented his trolley pole system of current collection from an overhead wire. To avoid contravening this patent, the Siemens company was forced to design its own, unique form of current collection, namely the bow collector. The bow collector was first used by the Siemens electric company in its early electric tramcars in either the late 1880s or early 1890s. The Hobart electric tramway system - the first of its kind in the Southern Hemisphere, opened in 1893 - used Siemens cars with very early bow collectors. Their construction is mentioned below. Many other continental European and some English tramway systems used this method, though it has now been largely replaced by the pantograph. Werner von Siemens Ernst Werner von Siemens (December 13, 1816 – December 6, 1892) was a German inventor and industrialist. ...
Frank Julian Sprague (1857-1934) American inventor, Father of Electric Traction Frank Julian Sprague (1857–1934) was an American naval officer and inventor who contributed to the development of the electric motor, electric railways, and electric elevators. ...
Jump to: navigation, search State nickname: Old Dominion Other U.S. States Capital Richmond Largest city Virginia Beach Governor Mark R. Warner (D) Senators John Warner (R) George Allen (R) Official languages English Area 110,862 km² (35th) - Land 102,642 km² - Water 8,220 km² (7. ...
Trolley poles are usually tapered cylindrical poles of wood or metal, used to transfer electricity from a live overhead wire to the control and propulsion equipment of a trolley car, tram or trolley bus. ...
An electric multiple unit pulling into Tile Hill station; Coventry, England. ...
Jump to: navigation, search Company headquarters in Munich, Germany Siemens AG NYSE: SI is the worlds largest electronics company. ...
Jump to: navigation, search A modern tram in the Töölö district of Helsinki, Finland Volkswagen Cargo-Tram in Dresden. ...
Jump to: navigation, search // Events and Trends Technology Development and commercial production of electric lighting Development and commercial production of gasoline-powered automobile by Karl Benz, Gottlieb Daimler and Maybach First commercial production and sales of phonographs and phonograph recordings. ...
The 1890s were sometimes referred to as the Mauve Decade, because William Henry Perkins aniline dye allowed the widespread use of that colour in fashion, and also as the Gay Nineties, under the then-current usage of the word gay which referred simply to merriment and frivolity, with no...
Hobart Coat of Arms View from the port of the city centre and Mt Wellington Hobart is the state capital of Tasmania, Australias island state. ...
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Jump to: navigation, search 1893 was a common year starting on Sunday (see link for calendar). ...
Jump to: navigation, search Royal motto (French): Dieu et mon droit (Translated: God and my right) Englands location within the UK Official language English de facto Capital London de facto Largest city London Area - Total Ranked 1st UK 130,395 km² Population - Total (mid-2004) - Density Ranked 1st UK...
Construction The bow collector is one of the simplest and most reliable methods of current collection used on tramways. The very earliest versions were simply very heavy-gauge wire or steel bars bent into a rectangular shape and mounted long-side-down on the tramcar roof. The height of the collector was such that its top edge would scrape along the wire above. The top section is made of a 1 inch broad (or thereabouts) steel rod, machined to have a bow-shaped cross section, hence the name. This bow shaped rod is referred to as the 'collector plate', and in later models may be up to several inches wide. Unlike many trolley poles, the bow collector does not have a revolving base, but is rather fixed centrally to the tramcar roof. Image File history File links Download high resolution version (1280x960, 609 KB) Beschreibung: Historischer Triebwagen 21 der Plauener Straßenbahn Quelle: [1] Fotograf: Daniel Möschke Lizenzstatus: GNU FDL Description: Historical in Plauen/Germany Source: [2] Photographer: Daniel Möschke Licence: GNU FDL File links The following pages link to...
Image File history File links Download high resolution version (1280x960, 609 KB) Beschreibung: Historischer Triebwagen 21 der Plauener Straßenbahn Quelle: [1] Fotograf: Daniel Möschke Lizenzstatus: GNU FDL Description: Historical in Plauen/Germany Source: [2] Photographer: Daniel Möschke Licence: GNU FDL File links The following pages link to...
Plauen, old townhall Plauen is a city in east-central Germany. ...
A wire is a single, usually cylindrical, elongated strand of drawn metal. ...
Mid-19th century tool for converting between different standards of the inch An inch is an Imperial and U.S. customary unit of length. ...
In the late 1900s the simple framing methods mentioned above were gradually replaced by more complex and sophisticated methods, but the general mode of operation remained the same. The changes of design are most noticeable on systems where both double- and single-deck cars were used on the same system. Single deck trams usually have tall and lightly constructed collectors with complicated frames to support the heavy cast-steel collector plate, while double deck cars usually have heavier collectors with less complicated frames. // Events and Trends Technology Lawrence Hargrave makes the first stable wing design for a heavier-than-air aircraft Orville and Wilbur Wright make the first documented flight in a powered heavier-than-air aircraft Mass production of automobile Wide popularity of home phonograph Panama Canal is built by the United...
To maintain good electrical contact, the bow collector must exert quite strong pressure on the wire above, and so complicated systems of springs or weights were put into use to ensure good electrical contact, and hence efficient operation was maintained.
The steel rails on the tracks act as the electrical return. Jump to: navigation, search Ground symbols The term ground (or earth) usually means a common return path in electrical circuits. ...
Operation Properly the bow collector should be mounted in such a way so that the top edge of the collector plate would rise several inches above the wire when the collector frame is standing straight up. Thus the collector usually leans opposite to the direction of travel, when the time comes to travel in the opposite direction, the collector must be swung over. To allow this to happen, the overhead wire must be raised by several inches at places where the bows are swung over, such as termini and turn-outs. This operation is usually achieved by ropes and pulleys. The collector is folded down to a horizontal position when the car is not in use.
Some early cars had no means to swing the bows over. It was thought that this would happen automatically when the tramcar started travelling the other way, but collectors such as these were a failure.
Advantages and Modern Usage The bow collector, unlike the trolley pole, does not have any moving parts, and so is simpler than the trolley pole, but heavier and sometimes more complicated to construct. The construction of overhead wires for bow collectors is quite simpler than trolley pole wiring. As bow collectors do not have revolving mountings, the collector cannot jump off the wire or follow the wrong one at intersections, as trolley poles sometimes do. Thus overhead 'frogs' and guides for trolley poles are not necessary with bow collectors.
The overhead wires for bow collectors are stretched tighter than for trolley poles, and straight sections are 'staggered', that is, the wire does not run completely straight down the centreline of the track, but rather zig-zags slightly across a small distance. This distributes wear across the bow collector's collector plate, and extends the collector's life.
If bow collectors have any electrical efficiency over that of trolley poles, they are negligible. Still, bow collectors are more convenient in operation than trolley poles, cheaper to construct, and free of troubles associated with trolley poles, such as de-wirings. Bow collectors are, however, much noiser than trolley poles.
The advantages of bow collectors are similar to those of pantographs, and the two systems are also vaguely similar in appearance.
The bow collector is now not used except in some vintage tramways.
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