Rail commuters and Tube travellers were hit by delays to morning rush-hour services today.
On the London Underground, a signal failure at Farringdon in the City of London led to severe delays to services on the Hammersmith & City and Circle lines, with delays also on the Metropolitan line.
A signal failure at Rayner's Lane in west London led to delays on the Piccadilly line between Uxbridge and South Harrow.
Main line services run by the First Great Western train company were affected by over-running engineering work near Swindon in Wiltshire.
Services between Swindon and Didcot Parkway were delayed for up to 45 minutes.
Passengers on Merseyrail services had to use buses instead of trains between Rock Ferry and Birkenhead Central.
This was due to a derailment of an empty passengers train at Rock Ferry.
A signalling problem at Stevenage in Hertfordshire led to delays on some services into London.
First Capital Connect services between Stevenage and Moorgate in London were not running between Stevenage and Watton-at-Stone, with buses replacing trains.
Other companies affected by the Stevenage problem were East Coast, First Hull Trains and Grand Central.
There were further delays to main line services in the last part of the rush-hour.
A signalling problem at Lewisham in south east London led to delays to passengers travelling on trains run by the Southeastern train company.
South West Trains passengers were affected by a broken-down train at Chessington North in south west London.
No trains were able to call at Chessington South, Chessington North, Tolworth or Malden Manor stations.
The Chiltern and London Midland train companies were affected by poor rail conditions at Old Hill in the West Midlands.
This caused delays of up to 60 minutes between Kidderminster and Birmingham Snow Hill.