Metro officials released their first batch of findings Wednesday after cars on a Metro Red Line train separated Nov. 24 in a tunnel near Glenmont station in Maryland’s Montgomery County.
According to the Washington Metrorail Safety Commission, the WMSC, the Washington Metropolitan Area Transit Authority and representatives from the coupler manufacturer “participated Monday and Tuesday in a detailed review of the coupler assembly involved” in the separation between Car 6177 and Car 6150.
Among the top findings is that there were five loose bolts on top of the coupler assembly for Car 6177.
One of those bolts was designed to hold the draft bar, which connects the coupler to the train and cars, in place in the coupler head. The other four are supposed to hold a guide rail in place to help prevent the coupler assembly from rotating.
The draft bar’s screw-like threads and the coupler head were “worn, damaged or flattened.” Corrosion and contaminants were found.
Additionally, it was found that “WMATA does not have the tools required to check the threads on the draft bar and coupler head during an overhaul process.”
Car 6177 last underwent regular maintenance Oct. 21.
Parts of the coupler involved in this separation had been included in WMATA’s fleetwide inspection of the 6000-series cars after a similar detachment in October near Union Station.
Metro sidelined its 6000-series fleet after last week’s separation, where 12 passengers had to be evacuated. One with a medical condition was taken to the hospital with a non-life-threatening condition. Two Metro employees also were on the train.
The safety commission says the investigation into the car separation remains in its early stages.
The Washington Metrorail Safety Commission’s full list of initial facts:
- The separation in this event was between Car 6177 and Car 6150. The coupler parts at issue have been identified on Car 6177.
- There were five loose bolts on the top of the coupler assembly.
- One of those bolts, the “clamping bolt” or “pinch bolt,” is designed to hold the draft bar in place in the coupler head.
- The other four bolts are intended to hold a guide rail in place that can help prevent the coupler assembly from rotating.
- The “clamping bolt,” or “pinch bolt” and guide rail bolts were not marked with torque stripes.
- The screw-like threads on the draft bar and coupler head were worn, damaged or flattened.
- Corrosion and contaminants were found on the threads of the coupler head.
- WMATA does not have the tools required to check the threads on the draft bar and coupler head during an overhaul process.
- Parts of this coupler were included in WMATA’s fleetwide inspection of 6000-Series cars following the Oct. 9 pull apart.
- The gland nut on the coupler involved in the Nov. 24 pull apart had a properly aligned torque stripe.
- In the Oct. 9 pull-apart near Union Station, the gland nut was not properly torqued. (The gland nut and the clamping bolt are in different parts of the coupler.)
- Car 6177 last underwent regular maintenance on Oct. 21 (periodic preventive maintenance inspection).
- After the Nov. 24 pull apart, the two sections of the train came to rest approximately 77 feet apart.
- The trailing car stopped approximately 266 feet from the platform.
- There were 12 customers and two WMATA employees on the train at the time of the separation.
- Metro personnel followed the proper chain of custody procedures prior to this week’s reviews of the couplers involved in the Nov. 24 pull apart.
WTOP’s Rick Massimo and Abigail Constantino contributed to this report.