1977 Chicago Loop derailment

1977 Chicago Loop derailment
Details
Date	February 4, 1977
Time	5:25 pm
Location	Chicago, Illinois
Country	United States
Rail line	The Loop
Operator	Ravenswood
Type of incident	Collision
Cause	Driver error
Statistics
Trains	2
Deaths	11
Injuries	Greater than 180

The 1977 Chicago Loop derailment occurred on February 4, 1977, at approximately 5:25 pm, when a Chicago Transit Authority elevated train rear-ended another on the northeast corner of the Loop at Wabash Avenue and Lake Street^[1] during the evening rush hour. The collision forced the first four cars of the rear train off the elevated tracks, killing eleven people and injuring over 180 as the cars fell onto the street below. It remains the single worst accident in the agency's history.

The crash involved a Ravenswood train composed of 6000-series cars (now called the Brown Line) and a Lake–Dan Ryan train (composed of two 2000-series and six 2200-series cars.) (a line which followed the route of the present day Green Line to the west and Red Line to the south). Earlier in the day, switching problems caused a third line, the Evanston Express (now the 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 and westbound Lake–Dan Ryan trains. As a result, the Ravenswood train had to stop short of the platform as it approached the first station past the turn, waiting for the rerouted Evanston Express to clear before proceeding. However, the Lake–Dan Ryan train immediately behind the Ravenswood did not stop, and proceeded against both track and cab signals. The Lake–Dan Ryan struck the back of the Ravenswood 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.

However, Martin continued to apply traction power to his train after the initial impact. Since the train was composed of multiple unit cars, this resulted in the rear cars continuing to push against the first four cars, which were on the bend of the track, but blocked by the Ravenswood train. Unable to move forward, the pressure 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 was still 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, and the fourth car was pulled off the tracks to dangle precariously between the tracks and street. The last four cars remained on the track, still in the station.

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.^[2] 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.

References

Chicago portal

1. ^ Owen, Mary. "Operator error caused Green Line derailment". Chicago Tribune. http://www.chicagotribune.com/news/local/chi-train-derailment-web-may29,0,185486.story. 
2. ^ Chicago-L.org - Mishaps and Unusual Occurrences - The Loop Crash

Coordinates: 41°53′08″N 87°37′34″W / 41.8855°N 87.6262°W / 41.8855; -87.6262