page_title: Pantograph (transport)
section_title: Invention
hierarchical_section_title: Pantograph (transport) / Invention
caption_attribution_description: English: Flat-section pantograph from early en:Baltimore and Ohio Railroad electric locomotive. The overhead conductor had an inverted "U" cross section, so lateral flexibility was needed on curves.
context_page_description: A pantograph is an apparatus mounted on the roof of an electric train, tram, trolleybus, trolley truck or electric bus to collect power through contact with an overhead line. Battery electric buses and trains are charged at charging stations. It is a common type of current collector. Typically, a single or double wire is used, with the return current running through the rails. The term stems from the resemblance of some styles to the mechanical pantographs used for copying handwriting and drawings.
context_section_description: The pantograph, with a low-friction, replaceable graphite contact strip or "shoe" to minimise lateral stress on the contact wire, first appeared in the late 19th century. Early versions include the bow collector, invented in 1889 by Walter Reichel, chief engineer at Siemens & Halske in Germany, and a flat slide-pantograph first used in 1895 by the Baltimore and Ohio Railroad
  The familiar diamond-shaped roller pantograph was devised by John Q. Brown of the Key System shops for their commuter trains which ran between San Francisco and the East Bay section of the San Francisco Bay Area in California. They appear in photographs of the first day of service, 26 October 1903.  For many decades thereafter, the same diamond shape was used by electric-rail systems around the world and remains in use by some today.
  The pantograph was an improvement on the simple trolley pole, which prevailed up to that time, primarily because the pantograph allows an electric-rail vehicle to travel at much higher speeds without losing contact with the overhead lines, e.g. due to dewirement of the trolley pole. 
  Notwithstanding this, trolley pole current collection was used successfully at up to 90 miles per hour (140 km/h) on the Electroliner vehicles of the Chicago North Shore and Milwaukee Railroad, also known as the North Shore Line.
caption: Early (1895) flat pantograph on a Baltimore & Ohio Railroad electric locomotive. The brass contact ran inside the ∏ section bar, so both lateral and vertical flexibility was necessary
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