Page:NTSB RAR-77-10.pdf/5

- 2 - INVESTIGATION

The Accident

Chicago Transit Authority (CTA) train No. 415 (Ravenswood) left Kimball Terminal at 4:35 p.m. on February 4, 1977. The train consisted of six 6,000-series, self-propelled cars. The trip to downtown Chicago was routine and about 5:22 p.m. the train passed Tower 12 onto the northbound track on the east side of the elevated track structure over Wabash Avenue. (See figure I.) When the train departed the Randolph Street Station and entered the curve at Wabash Avenue and Lake Street, the cab signal changed from a yellow aspect to a red aspect, because of a train ahead. After the Ravenswood train stopped, the red aspect changed to a flashing red aspect. The motorman knew that the reason for the red signal aapect was a train ahead and, in accordance with CTA rules, he kept his train standing at that point with the parking brakes applied and waited for a proceed signal. The curve begins 18 feet past the Randolph-Wabash Street Station.

CTA train No. 930 (Lake-Dan Ryan) departed the 95th Street Terminal on the West-South Line at 5:01 p.m. It consisted of eight 2,000-series, self-propelled cars and was operated by a motorman and a conductor.

There were no known equipment defects. The train made regularly scheduled stops en route to downtown Chicago with no reported problems. At Tower 12, the Lake-Dan Ryan train followed the Ravenswood train onto the elevated track structure. The motorman saw the Ravenswood train ahead with its lighted marker lights. Following his usual procedure, the motorman operated his train so that it was one station behind the Ravenswood train. He said that he saw the Ravenswood train when it left the Randolph Street Station and passed through the curve at Wabash Avenue and Lake Street.

According to the motorman's testimony, "When I stopped at Randolph, I did not see the train prior to my stopping at Randolph and Wabash. I thought he was in State and Lake because I felt assured that he had already cleared the curve because I did not see him in the curve." He also knew from experience that a Ravenswood train would be diverted to another route at Tower 18 and that it would no longer be of concern to him.

When the Lake-Dan Ryan train entered the Randolph Street Station, just south of the curve, the cab signal aspect should have changed from a "yellow 35" to a "yellow 15" which would have allowed a maximum speed of 15 mph. However, when the train passed the four-car mark on the