Rail passengers caught up in Wednesday's severe delays out of Reading station are to receive compensation.
Services to London Paddington were cancelled after a high-speed Hitachi test train ripped through 500m of overhead electric cables near Ealing on Tuesday night.
A loss of power to the line meant passengers were stranded at Reading for much of Wednesday's morning rush hour.
Season ticket holders will be refunded for two days and other passengers will have their fares paid back.
Great Western Railway is warning of further delays on Thursday night as some trains remain in the wrong place because of the disruption.