Nearly half of the TfL network is either reporting delays or part suspensions.
On the London Underground, the Bakerloo and Circle lines are experiencing minor delays because of a signal failure and a broken-down train respectively.
The District line, which stretches well into the commuter belt, is seeing severe delays due to a faulty train, transit officials say.
This is mainly in west London, between Earl’s Court and Wimbledon, Richmond, Ealing Broadway and Edgware Road
On the Metropolitan line, there is no service between Wembley Park to Aldgate – all of its central London route – due to a trespasser. This has rippled onto the Jubilee line, with the nearby stations between West Hampstead and Wembley Park not running.
The DLR is experiencing minor delays between Bank/Tower Gateway and Canning Town/Lewisham due to an earlier signal system failure at Poplar. The Overground was briefly experiencing delays but has settled down now.
But the chaos is actually worse than it seems, according to True Tube Status, a service that monitors London Underground routes.
The app says that the Central line – one of the most vital commuter lines – is seeing minor delays, with 21% longer journeys. Same for the Piccadilly line, which services Heathrow airport.
Circle line journeys are about 20% longer than normal, which True Tube Status reports amounts to severe delays rather than minor.
Most of the hobbled lines this morning are seeing journeys between 20 and 30% longer than normal.