Interesting reason for delays and cancellations - congestion between Willesden Junction and Clapham Junction! There are 3 trains per hour each way and according to NRE Southern aren't affected, leaving two Silverlinks per hour causing major congestion...
National Rail Enquries said:Time Reported: 12:49
Route Affected: Willesden Junction - Kensington Olympia - West Brompton - Clapham Junction
TOC/s Affected: Silverlink
Description: Train services between Willesden Junction and Clapham Junction are being disrupted due to congestion
Services are subject to cancellations and delays
The estimate for a normal train service to resume is 2-3 hours
Easements: Tickets are being accepted on the London Underground, local bus routes and on South West Trains between Clapham Junction and Richmond