On Monday March 14, Caltrain will return to its scheduled reduced service after the fiery crash on Thursday morning in San Bruno.  The crash left 13 people with non-life-threatening injuries when a southbound train hit work trucks that had been carrying catenary poles for the electrification project.

National Transportation Safety Board investigators reported on Friday night that the Caltrain’s Positive Train Control system, intended to prevent trains from crashing into other trains or construction activities, had been enabled at the time of the crash. The PTC system was installed to meet a federal mandate and had been live since 2019.

Long time rail watcher Adrian Brandt, who has followed the development of Caltrain’s train control and signaling system, assesses what may have gone wrong.

Some of the work trucks used on the electrification project don’t automatically alert the PTC system (passenger and freight trains do so). Brandt had recently observed a Balfour Beatty construction crew manually connecting jumper cables between the two rails in order to bring down crossing gates – in other words, some work groups need to take manual steps to alert Caltrain’s systems (see image below).

Brandt identifies three logical questions to diagnose what went wrong

• Did Balfour Beatty inform Caltrain’s dispatch about the location of the work crews?
• Did Caltrain’s dispatch system get a notice but not set the PTC system to protect the track?
• Did the PTC system, which was enabled, fail to correctly stop the train?

Investigators will analyze video and data from the locomotive and radio traffic. A preliminary report is expected in 2-3 weeks, and a final report is expected in 12-18 months; the reports will be posted on the NTSB website. The investigators are working with Caltrain, TASI (the company contracted to Caltrain to run the trains), Balfour Beatty, and the labor unions representing the railroad and construction workers involved.

On Friday, the NTSB investigators reported that the train had been traveling at about 60 miles per hour when it hit three work trucks holding cranes that place the poles that will hold the electric wires. The impact dragged the trucks over 500 feet before the train came to a stop. The fire that damaged the train was caused by a punctured fuel tank on one of the trucks. The NTSB held the damaged trucks and train in place until Saturday while assessing perishable evidence at the scene. A bus bridge carried passengers past the scene on Saturday, and service resumed on Sunday.

The service on Monday will be reduced as previously planned for electrification construction – but the reduced service will extend longer than April 1 in the original plan due to repairs needed from the crash.