A Metro train passes through King Street. by the author.

The Washington Metrorail Safety Commission said on Tuesday that the preliminary investigation into this month’s Red Line train pull-apart may have been a repeat of another pull-apart from 2018. CEO David Mayer told commissioners that “an improperly torqued bolt” was likely to blame for equipment from one railcar pulling off and remaining attached to another.

The WMSC’s investigation into the incident is ongoing and Mayer noted staff were still reviewing data, but that the link to the 2018 incident was being looked into. In the 2018 incident, the draw bar which connects two railcars pulled out of its socket, leaving a Silver Line train disabled outside the McLean station. This month’s pull-apart occurred in a different location between railcars, but in a near-exact circumstance.

In the 2018 incident, the “clamping bolt” which secures a rod inside a hollow chamber came loose, allowing the rod to come out. In the 2020 case, the rod came out, but the clamping bolt appears to have remained in place. Metro pulled all 6000-series railcars from service briefly to perform bolt and coupler inspections, and found 18 of the first 166 inspected to have had “potential concerns.” Of those, three had incorrect hardware installed, which could have led to more pull-aparts if left in service.

Metro says it’s still awaiting results of lab tests being performed on the bolt and nut in question to help narrow down the exact cause.

The agency made efforts after the 2018 pull-apart to create a new procedure to try and prevent reoccurrence of the bolt issue by calling attention to it and providing information about what to and what not to do during maintenance, but that appears not to have been as successful as the agency had hoped.

The WMSC also faulted Metro personnel for failing to secure and for messing with some of the evidence from the investigation. Without notifying WMSC personnel, a Metro manager directed an employee to perform a torque check on the bad coupler involved in the pull-apart, which changed the configuration of the piece of equipment.

Nothing was damaged or lost when the bolt was torqued, but it showed a failure of Metro personnel not following existing policies. Metro Chief Safety Officer Theresa Impastato told the Metro Board on Thursday she believes the employees weren’t acting of “nefarious origin,” but was rather the result of a mix of missing policies and a lack of understanding of existing investigation policies. Their test results were reported up to their manager, which Impastato noted was further indication that Metro wasn’t trying to hide or obfuscate evidence.

Impastato explained to the Board the tampering was made possible because the evidence wasn’t physically separated in the yard shop where it was being stored, and due to a lack of plastic wrap. The coupler, when temporarily stored at Brentwood yard before being moved to the Greenbelt yard further north, hadn’t been physically separated and protected as investigation evidence, which allowed easier access for employees. The coupler also wasn’t wrapped up in plastic to prep for shipping to Greenbelt because the shop didn’t have any.

Mayer noted to WMSC commissioners that this wasn’t the first time a Metro employee tried to modify evidence of an investigation, regardless of intent. The train operator involved in an August 2019 train collision in the Largo tail tracks attempted to “alter the scene by entering the stationary train, keying up the stationary train, and attempting to decouple the trains” in violation of Metro investigation policies.

A separate WMSC audit released last month also found gaps in Metro procedures surrounding incident investigations, especially when they involved Metro’s Rail Operations Control Center (ROCC). The commission found investigators failed to always get source documents like radio recordings, and rather relied on others, introducing the possibility that evidence could be mishandled.

As a result, the WMSC issued a new requirement on Tuesday that Metro ensure all workers know about its existing policies which govern “proper chain of custody and control of evidence” through initial and ongoing training. “Metrorail may also consider any necessary policy changes required to ensure all proper steps are followed to protect the integrity of all investigations,” the WMSC stated. Metro has 30 days to respond to the WMSC and identify their plan for distributing the training.

Train improperly sent through smoke

In a separate investigation report approved during Tuesday’s meeting, the WMSC said a Metro train was sent through a tunnel that could’ve had smoke in it, contrary to agency protocols. Personnel in an auxiliary room near the Yellow/Green line tracks at L’Enfant Plaza on February 4, 2020 were using a grinder to try and cut a lock off a locker instead of a bolt cutter, and ended up creating a cloud of smoke.

The Metro Automatic Train Control (ATC) personnel doing the grinding reported smoke to the ROCC, first to a maintenance controller, and then to the rail controller for the Yellow/Green lines. The door to the auxiliary room was opened, allowing smoke to escape, and tunnel fans in the area were activated.

Instead of offloading Yellow line train 309 to perform a track inspection, the train was left in service with passengers onboard while performing the inspection. The report says the operator reported a “good track inspection,” but that they were also “not told to look for smoke” but just “anything unusual.”

The WMSC’s Adam Quigley made note in an answer to WMSC Chairperson Christopher Hart that Metro personnel had made a habit of leaving out the word “smoke” or similar words during prior incident reports. “There has been a habit of either leaving out smoke or using other phrases that we have addressed our concerns with [Metrorail] and the safety department,” said Quigley.

Leaving out the key word “smoke” could erroneously lead Metro personnel to treat an incident as less serious that it might otherwise be, fail to offload trains when they should be empty for inspections, or something else.

Two “Lessons Learned” documents were distributed within Metro after the incident - one in the ATC group, and one in the ROCC - summarizing the incident and what personnel should have done. In addition to failing to offload the train to check for smoke, the lessons learned document also notes that track power was turned back on without the approval of Incident Command which could potentially have led to injuries if emergency personnel were on the tracks.

Metro ROCC staff were reminded by the document of an existing policy covering smoke or fire on the tracks, which says the next train to go through an area should offload before performing a track inspection.

Stephen Repetski is a Virginia native and has lived in the Fairfax area for over 20 years. He has a BS in Applied Networking and Systems Administration from Rochester Institute of Technology and works in Information Technology. Learning about, discussing, and analyzing transit (especially planes and trains) is a hobby he enjoys.