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The 1977 Chicago Loop derailment occurred on February 4, 1977, when a
Chicago Transit Authority
The Chicago Transit Authority (CTA) is the operator of mass transit in Chicago, Illinois, United States, and some of its surrounding suburbs, including the trains of the Chicago 'L' and CTA bus service. In , the system had a ridership of , o ...
elevated train
An elevated railway or elevated train (also known as an el train for short) is a rapid transit railway with the tracks above street level on a viaduct or other elevated structure (usually constructed from steel, cast iron, concrete, or bricks ...
rear-ended another on the northeast corner of the
Loop
Loop or LOOP may refer to:
Brands and enterprises
* Loop (mobile), a Bulgarian virtual network operator and co-founder of Loop Live
* Loop, clothing, a company founded by Carlos Vasquez in the 1990s and worn by Digable Planets
* Loop Mobile, an ...
at Wabash Avenue and
Lake Street during the evening
rush hour
A rush hour (American English, British English) or peak hour (Australian English) is a part of the day during which traffic congestion on roads and crowding on public transport is at its highest. Normally, this happens twice every weekday: on ...
. The collision forced the first four cars of the rear train
off the elevated tracks, killing 11 people and injuring at least 268 as the cars fell onto the street below.
Infrastructure layout
"
The Loop" not only refers to
Chicago
(''City in a Garden''); I Will
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's
central business district
A central business district (CBD) is the commercial and business centre of a city. It contains commercial space and offices, and in larger cities will often be described as a financial district. Geographically, it often coincides with the "city ...
, but also a rectangular pattern formed by the city's
elevated trains. Some trains entering the Loop do a complete circuit around the entire rectangular "loop", and after turning around all four corners, leave on the same path they came from. Other routes enter the Loop, turning only two of the corners, and then leave on a different route. Further complicating this is the fact that some trains' routes follow a clockwise pattern around the Loop, but others go counter-clockwise.
In 1977, when the crash occurred, there were four lines operating on the Loop, each in a different direction. The
Ravenswood Line (current Brown Line) operated counter-clockwise around the outer track, while the
Evanston Express (current Purple Line) and
Loop Shuttle operated clockwise opposite from the Ravenswood trains on the inner track. The
Lake–Dan Ryan Line (part of the current
Green Line) operated in both directions, but only using the Lake and Wabash legs of the Loop.
Earlier in the day of the accident, a switching issue forced dispatchers to reroute the Evanston Express to run counter-clockwise around the Loop instead of its normal clockwise route. This put it on the tracks normally used by the Ravenswood and westbound Lake–Dan Ryan trains. Because of congestion caused by this abnormal track sharing, the Ravenswood train would be required to stop short, waiting for the rerouted Evanston Express to clear before proceeding. Additionally, this delay meant that the Ravenswood was still in place when the Lake–Dan Ryan train arrived on these tracks, and it too was required to stop and wait for the Ravenswood to clear the track before proceeding.
Collision
At about 5:25 p.m., a Ravenswood train was waiting on the tracks, just past the northeast turn, waiting for the Evanston Express to clear the
State/Lake platform
Platform may refer to:
Technology
* Computing platform, a framework on which applications may be run
* Platform game, a genre of video games
* Car platform, a set of components shared by several vehicle models
* Weapons platform, a system or ...
. However, the Lake–Dan Ryan train did not stop as it approached the Ravenswood train. The Lake-Dan Ryan train proceeded against both
track
Track or Tracks may refer to:
Routes or imprints
* Ancient trackway, any track or trail whose origin is lost in antiquity
* Animal track, imprints left on surfaces that an animal walks across
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and
cab signals and struck the back of the Ravenswood train. This impact was at , as the train had only started off a few seconds earlier and was still halfway through pulling out of
Randolph/Wabash.
Passengers on the train reported the impact as nothing more than a "quiet thump."
![Union Loop](https://upload.wikimedia.org/wikipedia/commons/8/87/Union_Loop.png)
However, after the impact
motorman Stephan A. Martin continued to apply traction power. This resulted in the rear cars continuing to push forwards, pinning the front of the train against the waiting Ravenswood on the right-angle turn of the track. With the front Lake–Dan Ryan train unable to move forward, the pressure from behind caused the
coupling bar between the first two cars to bend and the coupled ends of those two cars to be pushed in the air. As motor power continued to be applied, the first three cars (two
Budd 2200 units and a single
Pullman-Standard 2000) were pushed further upwards, until they
jackknifed and fell off the tracks. The second and third cars fell all the way to the street below, while the first car fell onto a track support structure. The fourth car (another 2000 connected to the third car), pulled forward by the third, was derailed and dangled between the track edge and surface street. The last four cars remained on the track and still in Randolph/Wabash station.
Investigation and CTA response
While "traces of
THC
Tetrahydrocannabinol (THC) is the principal psychoactive constituent of cannabis and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) describes multiple isomers, the term ''THC' ...
" were found in one urine sample,
"the extent to which
artin
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* Artin (name), a surname and given name, including a list of people with the name
** Artin, a variant of Harutyun, an Armenian given name
* 15378 Artin, a main-belt asteroid
See also
{{disambiguation, surname ...
may have been under the influence of marijuana at the time of the accident could not be determined by tests."
Subsequent investigation revealed that Martin had a poor safety record, including reading while operating the train, and was responsible for an earlier derailment,
and he had a tendency to talk to passengers while driving the train.
Chicago-L.org - Mishaps and Unusual Occurrences - The Loop Crash
/ref> It is theorized that, having made the normal station stop before the curve, Martin had caused the restrictive cab signal caused by the train ahead to be overridden. Distracted, he then left the station at under , which was slow enough not to trigger the automatic control, and then after the initial collision, panic or inertia
Inertia is the idea that an object will continue its current motion until some force causes its speed or direction to change. The term is properly understood as shorthand for "the principle of inertia" as described by Newton in his first law ...
caused him to move the Cineston controller forward resulting in the derailment.
As a result of the accident, the CTA forbade motormen to proceed past a red signal "on sight" without first getting permission from the Control Center. 2200
In contemporary history, the third millennium of the anno Domini or Common Era in the Gregorian calendar is the current millennium spanning the years 2001 to 3000 (21st century, 21st to 30th century, 30th centuries). Ongoing futures studies se ...
units 2289-2290 and 2000
File:2000 Events Collage.png, From left, clockwise: Protests against Bush v. Gore after the 2000 United States presidential election; Heads of state meet for the Millennium Summit; The International Space Station in its infant form as seen from ...
units 2043-2044 were wrecked beyond repair and scrapped: all other trains involved were repaired and returned to service.
References
External links
NTSB Railroad Accident Report
{{DEFAULTSORT:Chicago Loop Derailment
Chicago Transit Authority
Railway accidents and incidents in Illinois
Railway accidents in 1977
History of Chicago
1977 in Illinois
February 1977 events in the United States
Accidents and incidents involving Chicago Transit Authority