A signal post fell across railway lines in Berkshire due to corrosion at its base, an accident report has found.
http://www.bbc.co.uk/news/uk-england-34335931
It was struck by a passenger train travelling at 110 mph (177 km/h) near Newbury on 17 November 2014.
The train was not derailed but the Rail Accident Investigation Branch (RAIB) report said the outcome could have been "much more serious".
The report recommended changes to how such signal structures are maintained in future.
The First Great Western high-speed train from Truro to London Paddington sustained exterior damage when it struck the top of the signal, which had partially blocked the track it was travelling on. The other track was completely blocked by the pole.
The
RAIB report said: "The outcome could have been much more serious if the first train to encounter the collapsed signal had been travelling at speed on the completely obstructed track."
It found the hollow steel post had corroded just above ground level, but could not been seen because it was hidden by ballast.
It said examination and maintenance of signal structures should be improved and a new specification of signal post should be developed.
A Network Rail spokesman said it would be "studying the recommendations in detail".