Yellow Line train crash caused by ‘design problem’ with braking system, investigators say

The Chicago Transit Authority’s Yellow Line train crash was caused by a “design problem” involving the train’s braking system, according to federal investigators.

The passenger train that slammed into a “snow fighter” track-plowing train, hospitalizing 23 people on Thursday, had a stopping distance nearly 1,000 feet too short, said Jennifer Homendy, National Transportation Safety Board chair.

“It was in fact a design problem. The braking distance should have been longer,” Homendy said at a Saturday news conference. “They should have had 2,745 feet to stop that train.”

The train’s proper braking distance changes over time as trains gain weight and additional passengers, Homendy said. The train’s braking system is designed to halt movement in 1,780 feet, she said.

“It didn’t. So now we need to determine why,” Homendy said.

Investigators viewed the train’s inward and outward facing cameras Saturday. They also probed the line’s signal system and the track’s condition. The train’s wheels slipped as the operator tried to brake before the crash, she said.

“We know there was some residue. It was thick and black on that part of the track,” she said.

It didn’t initially appear that the train operator was distracted, Homendy said. The crash was not caused by the unexpected presence of the snow fighter the passenger train collided with, she added. The snow fighter was on the tracks for scheduled pre-winter training and was stopped waiting for a signal when the crash occurred, she said.

“CTA’s system saw the snow equipment ahead. It was supposed to be there. They knew it was going to be there,” she said.

Similar situations in which trains slow because of other equipment stopped nearby on the track ahead have occurred 50 times in November, otherwise without incident, Homendy said, citing CTA data.

The train slammed into the snow fighter at 26.9 miles per hour, Homendy said. The CTA’s trains have a maximum speed of 58 miles per hour, she said. Six CTA workers were aboard the snow fighter, she added.

Investigators said they could not yet say when asked whether similar braking system issues might affect other CTA trains. However, Homendy said the system is safe.

“I would take the train tonight, tomorrow. I have no safety concerns about taking the train,” she said. “You are much safer taking the train than driving.”

While the NTSB does not yet have any recommendations for the CTA, the CTA can implement changes at any time, she added.

“They’re learning everything we are at the same time so that they can make safety change,” she said.

CTA officials did not immediately respond to questions about the braking system Saturday evening.

After a 2014 Blue Line crash at O’Hare International Airport injured more than 30 people and caused around $11 million in damage, the NTSB recommended the CTA install train-control technology, Homendy said at a separate news conference Friday.

The CTA uses “automatic” train control that controls speed to avoid crashes, but not the more comprehensive “positive” train controls that include actual speed adjustments, Homendy and lead investigator Jim Southworth said.

It is still unclear when the Yellow Line will resume rail operations, Homendy said.

jsheridan@chicagotribune.com

Originally Published: Nov 18, 2023 at 6:18 pm