Passengers on the District Line are facing severe delays on Monday morning while Transport for London deals with a derailed empty train.
Earlier commuters faced 30 minute delays at rush hour as some lines were blocked between Clapham Junction and London Victoria.
Trains are also unable to run between Willesden Junction and Richmond on the London Overground and there are severe delays between Stratford and Clapham Junction due to an obstruction on the overhead wires at Willesden Junction.
The Bakerloo line was also part suspended between Stonebridge Park and Harrow & Wealdstone while Network Rail fix a signal failure. It has led to delays on the rest of the line.There are also severe delays on both the Piccadilly and Northern Lines due to signal failures.
There are reports of slow traffic on various sections of the M25.