This is a combined preliminary summary describing the events surrounding the incorrect routing of two Washington Metropolitan Area Transit Authority (WMATA) trains at the Rosslyn station on August 27th and August 28th.
View of Rosslyn station looking outbound at the switch involved. Note there are two signals guarding the switch (displaying a white lunar aspect) Photo by Rail Transit OPS member Stephen Repetski
On Monday, August 27, 2018 at about 6:42 AM EDT WMATA Train 612 with a destination of Wiehle-Reston East serviced the Rosslyn station. Upon departure from the station Train 612 was supposed to take the switch located outbound of the station in the direction of Court House station. However, Train 612 continued straight following the Blue Line Route towards Arlington Cemetery. After passing the switch, the operator of Train 612 contacted the Rail Operations Control Center (ROCC) to inform the ROCC of the incorrect routing and was instructed to continue to Arlington Cemetery.
Rail Transit OPS Group believes the probable cause of the incident was the loss of situational awareness by the operator of Train 612 for not properly scanning the switch prior to passing the switch.
Contributing factors include the likely failure of the operator to enter the correct destination code on the train console. Based on preliminary information available from Metro Hero (via the original WMATA Application Programming Interface [API]), the train was transmitting a code relating to the Glenmont Rail Yard. Also contributing was the failure of the ROCC to identify and address the the incorrect destination code prior to the train reaching the Rosslyn station.
On Tuesday, August 28, 2018 at about 11:06 AM EDT WMATA Train 409 with a destination of Franconia-Springfield departed the Rosslyn station with its next planned station being Arlington Cemetery. Train 409 took an incorrect routing at the switch and traveled towards Court House station on the Orange and Silver Lines. The operator of Train 409 contacted the ROCC after having taken the incorrect routing. The ROCC instructed the operator of Train 409 to continue to Court House and offload the train and allow the passengers to travel back to Rosslyn to resume their trips.
Rail Transit OPS Group believes the probable cause to be loss of situational awareness by both the train operator of Train 409 for not properly scanning the position of the switch prior to passing it as well as the ROCC controller for failing to verify the correct routing at Rosslyn. This would be a necessary action as the automatic routing controls governing the C05-06 signal were disabled at the time.
Contributing to the incident was a heavy radio workload for the controllers in the ROCC at the time: transmissions for setting routing for trains at Rosslyn, managing track inspections, and communicating with track department personnel simultaneously. During the incident with Train 409, ROCC controllers were making multiple transmissions to multiple individuals, which could contribute to a loss of situational awareness.
In regard to both of the above incidents, there were no injuries, no damage to tracks or equipment, and at no time was the Automatic Train Protection (ATP) subsystem of Automatic Train Control (ATC) compromised, meaning there was no risk of a collision; ATP is programmed to prevent collisions with other trains regardless of the destination or direction of trains by detecting their presence through the rail system via track circuits.
With regards to Automatic Train Operation (ATO), the Automatic Train Supervision (ATS) subsystem would have verified that the route selected matches the destination entered on the train console and transmitted from the train, thus the August 27th incident should not have occurred if ATO were in use. However, the August 28th incident would likely have still occurred as the automatic routing system was disabled at Rosslyn, leaving the setting of the switches up to the ROCC controllers.
Review operating training procedures to ensure train operators properly scan switch points for proper alignment.
Rail Transit OPS Group provides independent evaluations of rail transit operations, performance, and safety processes as part of its dual mission: monitor and evaluate rail transit operators’ adherence to these processes, and provide additional information during service disruptions.
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