On a recent test run, RTD light-rail transportation manager Bill Bell, in the cab of car No. 271, came up to a red signal just south of the Alameda rail station. As Bell moved past the red light, an alarm sounded and onboard devices automatically slowed the train. Sand dropped to the tracks to aid braking, and the train shuddered to a stop. Along with light-rail operator Dino Andrew, Bell had successfully tested the ATS.
"We got our activation just as it should work," said RTD rail operations chief Cal Shankster of the test.
Fifty-five railcars that RTD is buying for its FasTracks program have factory-installed ATS technology. About 117 older light-rail cars are getting it as part of a retrofit the agency hopes to complete by the end of this year, Shankster said.
Equipment mounted near the wheels at the front of the train picks up electronic code from the track to "arm and enable" the train-stopping system, said Phillip Eberl, RTD's light-rail vehicle maintenance manager. The new safety procedure is considered a backup to the agency's automatic block signaling system, the principal means for keeping trains apart.
When a train operator encounters a red signal, it typically means another train is occupying the block, or segment, of track up ahead. Without ATS technology, a light-rail operator can inadvertently run through a red signal and, in a worst case, collide with another train.
The ATS system allows RTD operators to move past a red signal and travel under restricted speed when authorized by the rail control center. This option is needed when maintenance is being performed on the line, officials said.
RTD averaged about two incidents a month last year in which light-rail operators traveled past red signals in violation of the agency's rules, Shankster said. When it happens, an operator is taken off duty at the next station and must submit to a drug and alcohol test, he said.
"Passing a red signal without permission is considered one of the most serious safety infractions," Shankster said. "Discipline for a second red-signal violation within a one-year period is cause for termination of employment and is strictly enforced."