If you were travelling home to Surrey and Sussex with @SouthernRailUK and @TLRailUK last night (Tuesday) you will have been caught up in serious disruption after an electrical fire on the Brighton Main Line nr Purley. We are really sorry for the delays - here is what happened: 1/
@SouthernRailUK @TLRailUK Soon after 1700 (5pm) the 1636 Victoria to Reigate/Gatwick train stopped near Purley as the driver could see a fire on the track ahead. Trains in our area are mostly powered by the 750volt conductor rail, which sits at ground level, and it was that rail which was on fire. 2/
@SouthernRailUK @TLRailUK Electrical arcing can create extreme heat and it was not safe to run trains. Our electrical control cut the power to stop the fire, and left the track in the picture without electricity. Each track has separate electrical sections to allow for this, but they can be quite long. 3/ 
@SouthernRailUK @TLRailUK This close up shows how the lines to Oxted and beyond were still able to run, and @SouthernRailUK @TLRailUK and Network Rail colleagues at Three Bridges control worked to keep trains moving with only 3 out of 4 tracks available and trains already on their journeys. 4/
@SouthernRailUK @TLRailUK Trains couldn’t call at Coulsdon South, Merstham, Redhill and Earlswood in the southbound direction and most trains were diverting via the Quarry Line, usually used by fast trains to Gatwick and beyond this pic shows the situation. 5/
@SouthernRailUK @TLRailUK To keep those lines moving, we did what is called “thinning the service” or cancelling groups of trains to stop everything jamming up. Those trains included Victoria to Caterham services, which is why those passengers suffered such a difficult evening – for which we apologise. 6/
@SouthernRailUK @TLRailUK Cancelling what we call “service groups” is a difficult decision to make and never popular but it means the railway can recover from delays more quickly and means as many people as possible are kept moving. It also means delays don’t spread as far or as fast. 7/
@SouthernRailUK @TLRailUK As you can see from the scorch, the fire was small but intense and the power was back on by 1747. Such is the intensity of services, even this short interruption was enough to cause serious disruption and @GatwickExpress trains had to be suspended for a while to free space. 8/
@SouthernRailUK @TLRailUK @GatwickExpress Our railway is one of the busiest in the world and saturated with trains at peak times. Trying to keep as many of them moving as we can when something goes wrong is a challenge. If that challenge is something that inspires you, we are recruiting: networkrail.co.uk/careers/
Thank you
Thank you
