Testing equipment wire caused brake issue; not car or operators; new cars on schedule
There was no malfunction of the train car and no operator error April 22 when a car being used for operator training on a Hayward test track ran into a sand box after a brake issue, BART officials said Wednesday.
The schedule for rollout of the new cars, BART’s highly awaited Fleet of the Future, will not be affected.
“When you’re testing cars, things can happen; and we learn from these things, that’s why it is called testing,” said Chief Maintenance and Engineering Officer Tamar Allen.
The crux of what happened: A wire running from testing equipment to the train car shorted out when pinched in a cabinet door. This caused the auxiliary power supply to short to ground and shut down. This is the system that supplies power to the pump that replenishes the brake fluid.
As a result, once the fluid in the accumulator had been expended it was not replenished. The electric brakes slowed the car to 5mph; the friction brakes did not have adequate fluid to complete the stop and the car rolled into the sand box. This failure can only occur with a single car (which does not happen in passenger service) because in a train the other cars in the train would carry through the braking process.
“The incident was caused by a pinched wire connecting the car to test equipment. It was not due to malfunction of the car or actions of the operator,” New Car Program Manager John Garnham said.
“We look at it as a learning experience,” he said. “We’re going to implement some software changes to provide more protection for single car moves and update procedures to protect against this type of failure in the future.”
Allen and Garnham both said there was never any safety issue and they had complete confidence that the new cars were going to serve the Bay Area well, help relieve capacity issues, give customers a quieter and more comfortable ride, and create quieter conditions in the neighborhoods around BART.
“The car functioned exactly as it was supposed to function given the conditions, and the operators did exactly what they were supposed to do,” Allen said.
“We’ve been testing this equipment for months, and will continue for several more months in order to ensure that these cars are safe,” Garnham said. Read more about the testing process in this story.
Testing will resume shortly after the new software is implemented. “They’re going to be great trains, they’re going to be state-of-the-art,” Garnham said.
BART expects new cars to be carrying riders later this year. More info is at www.bart.gov/cars.