Buffer stop

(Redirected from Stopblock)

A buffer stop, bumper, bumping post, bumper block or stopblock (US), is a device to prevent railway vehicles from going past the end of a physical section of track.

This buffer stop at Zurich HB in Switzerland is designed to move up to 7 metres (23 ft) to slow down an 850-tonne (840-long-ton; 940-short-ton) passenger train from 15 km/h (9.3 mph) without damaging the train or injuring passengers.

The design of the buffer stop is dependent, in part, on the kind of couplings that the railway uses, since the coupling gear is the first part of the vehicle that the buffer stop touches. The term "buffer stop" is of British origin, since railways in Great Britain principally use buffer-and-screw couplings between vehicles.

Types

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Several different types of buffer stop have been developed. They differ depending on the type of coupler used and on the intended application.

  • Buffer stops with anticlimbers. These are particularly important for passenger railway applications, because the anticlimbers reduce the likelihood of telescoping of the railroad cars during a head-on impact.
  • Buffer stops for a knuckle coupler or an SA3 coupler (centrally positioned between the two rails)
  • Buffer stops with traditional "buffers" on either side
  • Hydraulic buffer stops
  • Friction buffer stops (bolted down to the rail)

If there is extra room behind the bumper block, there is usually a sand or ballast drag that is designed to further retard a runaway train. One such accident occurred in 1975 on the London Underground system, when a Northern City Line train powered past the bumper block at Moorgate station.

Energy-absorbing

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Largely because of its mass, a train transfers an enormous amount of kinetic energy in a collision with a buffer stop. Rigid buffers can safely cope only with very low-speed impacts. (i.e., nearly stationary). To improve stopping performance, a way of dissipating this energy is needed, through compression or friction. Following a buffer stop accident at Frankfurt am Main in 1902, the Rawie company developed a large range of energy-absorbing buffer stops. Similar hydraulic buffer stops were developed by Ransomes & Rapier in the UK.[citation needed]

Examples

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  • Raja Trains Depot in Tehran
    • Stopping speed: 20 km/h (12 mph)
    • Stopping distance: 20 m (66 ft).[1]

Wheel stop

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Wheel stops or car stops are used to stop small numbers of light vehicles at the end of level storage tracks or to chock individual railroad cars on shallow grades.[2][3][4][5][6]

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Examples of accidents

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The aftermath of the Gare Montparnasse accident

See also

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References

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  1. ^ "Infrastructure (Iran)". Railway Gazette International. 1/2009: 16. January 2009.
  2. ^ "Aldon railcar wheel stops". Archived from the original on 2018-08-19. Retrieved 2018-08-19.
  3. ^ "Rails Company – Wheel Stops". Archived from the original on January 30, 2020.
  4. ^ "Wheel Stops – Track Components". kimessteel.com.
  5. ^ "Western Cullen Hayes Wheel and Car Stops". Archived from the original on 2018-08-26. Retrieved 2018-08-19.
  6. ^ "Car Stops – The Nolan Company". nolancompany.com. 4 February 2016.
  7. ^ "A Csepeli Hév fekete áprilisa – 33 éve történt a tragikus HÉV baleset". Retrieved 11 November 2012.
  8. ^ "Argentine train crash kills 49 people, hurts 600". Yahoo.com. 22 February 2012. Retrieved 22 February 2012.
  9. ^ "10 años de la tragedia ferroviaria de Once en Argentina". 2022-02-22. Archived from the original on 2022-02-22. Retrieved 2024-05-24. [las pericias] constataron [...] que los paragolpes no contaban con su sistema hidráulico en funcionamiento [...]
  10. ^ "Stockholm train crashed into apartments 'by cleaner'". BBC News. January 15, 2013.
  11. ^ Camus, Miguel (August 19, 2014). "DOTC: Human error blamed for MRT-3 train accident; 4 train workers face raps". Philippine Daily Inquirer. Retrieved December 17, 2022.
  12. ^ Mahesh, Niha. "32 Die as Train Derails Near Rae Bareli in Uttar Pradesh, 50 People Injured". NDTV India. Retrieved 20 March 2015.
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