1977 Chicago Loop derailment

1977 Chicago Loop derailment
Details
Date	February 4, 1977 5:25 pm
Location	Chicago, Illinois
Country	United States
Line	The Loop
Operator	Ravenswood
Incident type	Collision
Cause	Driver error
Statistics
Trains	2
Deaths	11
Injured	Greater than 180

The 1977 Chicago Loop derailment occurred on February 4, 1977, when a Chicago Transit Authority elevated train rear-ended another on the northeast corner of the Loop at Wabash Avenue and Lake Street during the evening rush hour. The collision forced the first four cars of the rear train off the elevated tracks, killing 11 people and injuring over 180 as the cars fell onto the street below. The collision occurred less than a month after the Granville rail disaster in Australia.

Infrastructure layout

"The Loop" not only refers to Chicago's central business district, 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.

(Note that at the time of the accident, the CTA had not adopted color coding for its routes. However, to provide clarity for the contemporary reader, this article will use those colors where they correspond to today's routes.)

The 1977 crash itself involved trains from two lines. One was Ravenswood Line (today known as the Brown Line) and Lake–Dan Ryan Line (which no longer exists). However, a third train, from the Evanston Express (Purple Line), factored in as well.

Earlier in the day of the accident, a switching issue forced dispatchers to reroute the Evanston Express (Purple Line) to run counter-clockwise around the Loop instead of its normal clockwise route. This put it on the tracks normally used by the Ravenswood (Brown Line) 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 composed of 6000-series cars was waiting on the tracks, just past the northeast turn, waiting for the Evanston Express to clear the State/Lake platform. However, the Lake–Dan Ryan train, composed of 2000-series and 2200-series cars, did not stop as it approached the Ravenswood train. The Lake-Dan Ryan train proceeded against both track and cab signals, and struck the back of the Ravenswood. This initial impact was at a relatively slow speed, as the motorman, Stephan A. Martin, had just left a station. Passengers on the train reported the initial impact as nothing more than a slight bump.

"The Loop" refers to the rectangular routes of Chicago's elevated trains

However, Martin continued to apply traction power to his train after the initial impact, and this resulted in the rear cars continuing to push against the first four cars. These four cars were not only now pinned between the Ravenswood and their own rearmost cars, but they were also located on the bend of the track. Unable to move forward because they were blocked by the Ravenswood, the pressure from the rear caused the coupling bar between the first two Lake–Dan Ryan cars to bend and the ends of those two cars to be pushed in the air. The motor power continued to be applied, eventually pushing the first three cars upwards enough to the point that they jackknifed and fell off the tracks. The second and third cars fell all the way to the street below, while the first fell on one of the support structures for the tracks. The fourth car was pulled off the tracks and dangled precariously between the tracks and street. The last four cars remained on the track, still in the station.

Investigation and CTA response

Subsequent investigation revealed that Martin had been smoking marijuana and had four marijuana cigarettes in his shoulder bag. He also had a poor safety record and was responsible for an earlier derailment, and he had a tendency to talk to passengers while driving the train. 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 15 miles per hour, which was slow enough to not trigger the automatic control, and then after the initial collision, panic or inertia 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.