Pilot (locomotive)

Pilot (locomotive)
Leading truck and pilot on the John Bull
Pilot of a modern locomotive. (Indian locomotive class WAG-9)
Lifeguard (circled) on a UK HST powercar

In railroading, the pilot is the device mounted at the front of a locomotive to deflect obstacles from the track that might otherwise derail the train. In some countries it is also called cowcatcher or cattle catcher.

In addition to the pilot, small metal bars called life-guards, rail guards or (UK) guard irons are provided immediately in front of the wheels. They knock away smaller obstacles lying directly on the running surface of the railhead. Historically fenced-off railway systems in Europe relied exclusively on these devices and forwent the use of pilots, but this design is rarely used in modern systems.

Trams use in place of the pilot a device called a fender. Objects lying on the tram track get hit by a sensor bracket, which triggers the lowering of a basket shaped device to the ground preventing overrunning of the obstacles by dragging it along the road surface in front of the wheels.

In snowy areas the pilot has also the function of a snowplow.

Contents

Invention

The pilot was invented by Charles Babbage in the 19th century, during his period of working for the Liverpool and Manchester Railway.[1] However, Babbage's invention was not built, and it is uncertain whether later users were aware of Babbage's idea.

Design

On a mainline locomotive, the pilot has to successfully deflect an obstacle hit at speed; the ideal is to push it upwards and sideways out of the way. The locomotive should not lift on impact or the train will follow, and the ideal is for a fairly smooth structure so that the locomotive will not get caught and derailed.

The typical shape is a blunt wedge that is shallowly V-shaped in plan. In the later days of steam locomotives, the front coupler was designed to swing out of the way also, so it could not get caught up; this was called a drop coupler pilot.

Early on, pilots were normally fabricated of bars mounted on a frame; later on, sheet metal pilots were often used for their additional smoothness, and some cast steel pilots were employed for their mass and smooth shape. Early diesel locomotives followed the same plan.

Early shunting locomotives often had a pilot with steps on it to allow yard workers to ride on the locomotive; these were called footboard pilots. In some countries, footboard pilots are outlawed for safety reasons, and have been removed. Modern locomotives often have front and rear platforms with safety rails where workers can ride.

Modern pilots

Most modern European rail vehicles must have pilots with snowplow function and rail guards by law. The required strength of the system is 30 kN (3,059 kp) in the middle of the track and 50 kN (5,099 kp) near the rails.[2]

Modern US diesel locomotives have flatter, less wedge shaped pilots; this is because a diesel locomotive has the cab near the front, and the crew are vulnerable to impact from obstacles pushed up by the pilot.

Anti-climbers

Anti-climbers engaged on two Washington Metro rail cars following a collision in June 2009.

To protect the crew and passengers, most modern locomotives and passenger cars are fitted with a device known as an anti-climber above the coupler to prevent colliding objects from travelling up over the frame and through the locomotive cab area or through the passenger car. Where a pilot is not fitted, a different type of anti-climber may be used. This is to prevent one passenger car from riding up over another in a collision.

See also

References

  1. ^ Hyman, Anthony (1982). Charles Babbage, Pioneer of the Computer. Oxford University Press. pp. 142–143. ISBN 0-19-858170-X. "Babbage suggested to Hodgson of the railway company what was later to be called a 'cow-catcher' for sweeping obstacles off the line." 
  2. ^ "§ 41 Bahnräumer und Schienenräumer" (in German). Verordnung über den Bau und Betrieb der Straßenbahnen (Straßenbahn-Bau- und Betriebsordnung - BOStrab). 2008-11-07. http://www.buzer.de/gesetz/5894/a81357.htm. Retrieved 2009-03-29. 

Further reading

  • "Notes and News: Pilot Engines, Past and Present". The Railway Magazine (Westminster: Railway Publishing Company) 91 (556): 117–118. March & April 1945.  - describes seven other meanings of the word "pilot" historically used on Britain's railways.

Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • Pilot — can refer to:Paper publications* Pilot (short story) by Stephen Baxter *, a historical fiction novel by James Fenimore Cooper *The Virginian Pilot, newspaper serving the Hampton Roads part of Virginia *The Pilot (Lewisporte, Newfoundland and… …   Wikipedia

  • Pilot — Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who throws …   The Collaborative International Dictionary of English

  • Pilot balloon — Pilot Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who… …   The Collaborative International Dictionary of English

  • Pilot bird — Pilot Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who… …   The Collaborative International Dictionary of English

  • Pilot boat — Pilot Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who… …   The Collaborative International Dictionary of English

  • Pilot bread — Pilot Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who… …   The Collaborative International Dictionary of English

  • Pilot cloth — Pilot Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who… …   The Collaborative International Dictionary of English

  • Pilot engine — Pilot Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who… …   The Collaborative International Dictionary of English

  • pilot film — Pilot Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who… …   The Collaborative International Dictionary of English

  • Pilot fish — Pilot Pi lot, n. [F. pilote, prob. from D. peillood plummet, sounding lead; peilen, pegelen, to sound, measure (fr. D. & G. peil, pegel, a sort of measure, water mark) + lood lead, akin to E. lead. The pilot, then, is the lead man, i. e., he who… …   The Collaborative International Dictionary of English

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”