A passenger train heading towards Swansea hit a trolley left on the tracks while travelling at 123mph. The industrial trolley had been left during maintenance work, a Rail Accident Investigation Branch (RAIB) found.
The Great Western Railway service was speeding through Challow, Oxfordshire, on its journey from London Paddington to the Welsh city.
The train was damaged and the trolley was destroyed, but no-one was injured in the collision, which happened shortly after 6am on October 21 last year.
