The Collaborative International Dictionary
Telescope \Tel"e*scope\ (t[e^]l"[-e]*sk[=o]p), a. Capable of being extended or compacted, like a telescope, by the sliding of joints or parts one within the other; telescopic; as, a telescope bag; telescope table, etc.; -- now more commonly replaced by the term telescoping.
Wiktionary
n. The act of extending or contracting in the manner of a telescope. vb. (present participle of telescope English)
Wikipedia
In a railway accident, telescoping occurs when the underframe of one vehicle overrides that of another, and smashes through the second vehicle's body. The term is derived from the resulting appearance of the two vehicle bodies: the body of one vehicle may appear to be slid inside the other like the tubes of a collapsible telescope - the body sides, roof and underframe of the latter vehicle being forced apart from each other.
Telescoping often results in heavy fatalities if the cars telescoped are fully occupied. The car riding on top will often be destroyed by the structure of the car below, leaving very little survivable space (although the physics of the incident may reverse the cars' roles). The chances of telescoping can be reduced by use of anticlimbers and crash energy management (CEM) structural systems.
Accidents where telescoping occurred are numerous and include:
- 1952 Harrow and Wealdstone rail crash
- 1957 Lewisham rail crash
- 1972 Chicago commuter rail crash
- 1975 Moorgate tube crash
- 1981 Seer Green rail crash
- 1988 Chūō Main Line train collision
- 1990 Ursus rail crash
- 2008 Chatsworth train collision
- June 2009 Washington Metro train collision
- 2010 Hakodate Main Line crash
- 2012 Buenos Aires rail disaster
- 2013 Keikyū Main Line crash
- 2014 Tōkyū Tōyoko Line train collision
To reduce the chance of telescoping, rail and tramway vehicles are often provided with an anticlimber: a horizontally ridged plate at the end of the chassis, which in a collision will engage with the anticlimber on the next car.
22, 2009 WMATA Collision - NTSB accident photo 422860.jpg|The aftermath of the June 22, 2009 Washington Metro train collision Johns train crash 1898.jpg|The aftermath of the St Johns train crash 1898 where the rear two carriages of a passenger train were telescoped by being hit at 8mph by a following train.
Telescoping in mechanics describes the movement of one part sliding out from another, lengthening an object (such as a telescope or the lift arm of an aerial work platform) from its rest state. In modern equipment this is often done by hydraulics, but pulleys are used for simpler designs such as extendible ladders & amateur radio antennas.
See also Telescopic cylinder.
Category:Mechanics Category:Simple machines
Usage examples of "telescoping".
He drew back his arm and the spring-javelin snapped open, the two halves telescoping out from the center hand-grip and locking in place.
He had triggered another spring-javelin while under the creature, using the force of the ends telescoping out to push the Leaper up and off him.
Instead of simply burning their way into a ground-level position, the new units were fitted with telescoping walls that extended downward as a tunnel was burned to accommodate them.
With steam hissing from every joint in the telescoping legs, in slow, ragged stages the Royal walker eased into a kneeling position and gently leaned against a smoldering building.
He reached under the front of the van and took hold of the protruding end of the telescoping pole.
Rather to my chagrin, it was I who introduced such dubious topics as clairvoyance, mental telepathy, and the possibility of strange telescopings and other distortions of time and space during dream states.