London rail services hit by plummeting temperatures
Rail passengers in south London could face more travel problems over the weekend as temperatures are expected to remain around feezing.
London Overground services were disrupted and several Eurostar trains were cancelled on Friday.
Operations are returning to normal at London City and Heathrow Airports.
Freezing fog and ice causes problems on the railway tracks as it creates an insulating layer on the conductor rail, preventing trains being able to draw power.
Diesel trains that spray de-icer fluid on to the lines have been running and "ghost" trains have been operating to help keep ice off the conductor rail during the night. Teams are also being sent out to de-ice frozen points.
Frozen water pipe
Earlier services on London Underground were suspended between Sydenham and Crystal Palace.
On London Overground, a special service of eight trains per hour has been running between Dalston Junction and West Croydon, with no trains operating between Sydenham and Crystal Palace. There was also a special service on the East London Line.
A Transport for London spokesperson said: "TfL's fleet of 38 gritters and 10 quad bikes have been at work around the clock spreading nearly 1,000 tonnes of grit on roads and pavements of the strategic road network in the last 24 hours alone. Traffic is flowing across London, although there may be some delays where the conditions mean traffic is moving slowly.
"Almost 17,000 tonnes of salt remain from our 18,000 tonne operational stock. This is on top of TfL's 27,000 tonne strategic salt reserve."
First Capital Connect said there would be no service over the weekend on the Sutton-Wimbledon loop due to "frozen infrastructure".
A limited service will operate on the Brighton to London and Bedford to London routes.
The Southern rail route will also see fewer trains between Brighton and London Victoria, with services to several locations in Surrey and Sussex suspended over the weekend.
A reduced service is also expected on both Southeastern and South West train routes to and from London.
The wintry weather also hit services on the Eurostar which saw 17 trains cancelled on Friday and other trains running with 90 minute delays.
Services are returning to normal at Heathrow Airport and London City Airport, with some minor delays. Passengers have been advised to check with their airlines before travelling.
Meanwhile a frozen water valve affected water supplies to properties in south-east and south-west London.
Thames Water said supplies were restricted to homes in SW9, SW11, SE1, SE5, SE11, and SE17 and it had received calls from about 150 customers.
But water pressure was restored later as engineers managed to thaw out the jammed valves using heaters.