Update at 5:40 p.m.
Metro-North Railroad says the affected wheel was unable to rotate because its brake discs failed to release.
Railroad spokeswoman Majorie Anders said the incident is being investigated by Metro-North and the car's manufacturer, Kawasaki. She said dragging the stuck wheel along the rail caused it to heat up and develop a 6-inch flat spot.
Anders said the car has been taken out of service for repairs.
"Metro-North tests the brake system on every train every day," Anders said. "We believe this is an isolated incident."
Metro-North Railroad is investigating why a wheel on one of its new M-8 cars apparently seized early Thursday morning on a train carrying passengers, causing the stuck wheel to be dragged along the rail.
The incident occurred after 1 a.m., with the eastbound train’s crew becoming aware by feel or noise that the last car apparently had a flat wheel. The train stopped at the , and the crew climbed down onto the roadbed to inspect the car’s wheels.
The conductor radioed the rail traffic controller in New York that one of the wheels was so hot, “you can smell it.” He also reported there was a nine-inch-long “flat spot” on the wheel.
The flat spot could have been caused by the wheel being unable to rotate, so the portion of it being dragged along the rail became filed down.
Metro-North Railroad spokeswoman Marjorie Anders said the car is in the Stamford yard and the information from its data recorder is being downloaded.
“It could be a while,” Anders said of getting results from the investigation.
More than 20 of the cars have been delivered from the factory in Kobe, Japan, where they are being manufactured. The railroad has ordered 300 M-8, with most of them to be built in Lincoln, NE.
The first time a train consisting of M-8 cars carried passengers was March 1.