Why do south London trains suffer most in the snow?
Why are trains in south London more affected by snow than those elsewhere?
If you think it's train companies in south London that are the worst affected by the weather - you'd be right.
And there is I'm told a technical reason for this.
That is, the electricity is transmitted to the train using an electrified third rail that the train picks up through a bit of metal called a shoe.
So, while Network Rail have been running "ghost trains" (empty trains) and de-icing trains through the night there comes a point when it doesn't help.
When the snow and ice hits, if the conductor third rail is cold as soon as snow hits it, it freezes.
That means there's an insulating layer of ice between the shoe and the rail.
Southeastern have told me the trains automatically shut down to prevent "arcing" of electricity - that could damage electrics and is potentially dangerous.
The pertinent point is we are the only country in the world where the third rail system is being used outside an urban area (it's also used on the Tube and has caused problems on the uncovered Metropolitan line in the past).
And why was it introduced?
It was introduced in the 1930s and I've been told it was in the main due to cost as it's cheaper than erecting overhead power lines that we see to the north and east of London.
It also shows why C2C services, for example into Essex which uses overhead power lines, hasn't been as badly affected by similar levels of snow.
According to Wikipedia: "Three lines of five making up the core of Barcelona Metro network changed to overhead power supply from third rail. This operation was also done by stages and completed in 2003.
"The opposite took place in south London. The South London Line of the LBSCR network between Victoria and London Bridge was electrified with catenary in 1909.
"The system was later extended to Crystal Palace, Coulsdon North and Sutton. In the course of main-line third rail electrification in south-east England, the lines were converted by 1929."
Please let me know if you have any thoughts on this. I would be interested to hear from drivers in particular.
Also, I just received this from Association of Train Operating Companies:
National Rail Enquiries (NRE), run by and paid for by train companies, has today set up a dedicated phone hotline to provide passengers with up to date information about disruption caused by snow.
The number to call is 08453 017 641.
The hotline, which will allow passengers to choose the train company they travel with and to hear recorded updates about any disruption, comes in addition to the range of services already provided by NRE for passengers, including:
- The NRE website www.nationalrail.co.uk which includes a dedicated disruption page, an overview of all operators' services, and live departure boards of train services
- The automated train tracker service on 0871 200 49 50, which will give passengers up-to-date information about their services
- Twitter updates at @nationalrailenq and an NRE Disruption Facebook page