page_title: Railroad switch
section_title: Single-point switch
hierarchical_section_title: Railroad switch / Types / Single-point switch
caption_attribution_description: English: Single-point streetcar switch in Toronto, Canada, on the St. Clair line. Français&#160;: Aiguillage de tramway à une seule aiguille sur la ligne de Saint-Clair, à Toronto, Canada.
context_page_description: A railroad switch, turnout, or [set of] points is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.
  The switch consists of the pair of linked tapering rails, known as points, lying between the diverging outer rails. These points can be moved laterally into one of two positions to direct a train coming from the point blades toward the straight path or the diverging path. A train moving from the narrow end toward the point blades is said to be executing a facing-point movement.
  Unless the switch is locked, a train coming from either of the converging directs will pass through the points onto the narrow end, regardless of the position of the points, as the vehicle's wheels will force the points to move. Passage through a switch in this direction is known as a trailing-point movement.
  A switch generally has a straight "through" track and a diverging route. The handedness of the installation is described by the side that the diverging track leaves.
context_section_description: Single point switches, known as Tongue and Plain Mate switches, are sometimes used on freight railways in slow speed operation in paved areas such as in ports. In the United States, they are regulated by provision 213.135(i) of the Federal Railroad Administration Track Safety Standards.
  On streetcar (tram) systems using grooved rails, if the wheels on both sides of the car are connected by a rigid solid axle, only one switchpoint is needed to steer it onto one or the other track. The switchpoint will be on inside rail of the switch's curve route. When a streetcar enters the curve route of the switch, the wheel on the inside of the curve (the right side of the car on a right turn) is pulled into the turn, and through the axle, directs the wheel on the outside to also follow the curve. The outside wheel is supported for a short distance by its flange running in the groove.
  Some low floor streetcar designs use split axles (a separate half-axle for the wheel on each side of the car). Such streetcars are unsuitable for use with single-point switches as there would be no mechanism to transfer the force from the inner to outer wheels at switches.
  A single-point switch is cheaper to build, especially in street trackage, as there is no need to link to a second switchpoint.
caption: A single-point switch on the Toronto streetcar system
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