wheel flat
noun1
Rail transport, Railways, Transport A flat spot on a railway wheel caused when a wheel, or both wheels on the same axle, in a moving train stop rotating.
- Severe wheel flats caused by locking brakes led to the derailment of DB Cargo UK's 2152 Robeston-Theale oil train near Llangennech, in South Wales, on August 26.2020 October 7, “Network News: Severe wheel flats caused Welsh oil train derailment”, in Rail, page 14: