Power cut!
Network Rail is changing the way it cuts power to the third rail system, to free up more time for track maintenance. PAUL CLIFTON joins an overnight team in south London to learn how
How Network Rail is changing the way it cuts power to the third rail system, to free up more time for track maintenance.
It’s 0130, and the last train has just passed on its way from London Waterloo to the South Coast. Well away from the tracks, Matt Farrell flicks a switch at the Hampton Court Junction substation. The power to the electric third rail is turned off with a series of muffled bangs from inside the building. The night shift can get to work.
Sounds simple, doesn’t it? Network Rail reckons it’s revolutionary.
That’s because for decades, making the rails safe for workers has taken up to an hour. The process is known as ‘strapping’. It’s a manual task - applying a wire strap to short circuit the rail, ensuring that it cannot carry power.
First the rail is scrubbed with a wire brush to remove any loose material. Then a wire is clamped onto each running rail, and subsequently also attached to the power rail. Finally, a metal bar on a wooden pole is placed between the two. “Eyes!” shouts the man doing it, so that others can look away, just in case there is a flash.
“It’s to protect staff in the event of the power being accidentally returned to the tracks while they are working on them,” explains Jack Roberts, project manager for the Wessex Inner Maintenance Unit of Network Rail.
“This is a laborious process. It involves a large number of staff and takes a great deal of time. Tonight, we have a number of teams out just south of Surbiton station. They’re removing rail defects and stressing the rails. They’re also clearing scrap metal.”
Only when the strapping has been completed, checked, and checked again can the teams start the night’s work. Nothing else can be done until the track is safe. Tonight, that means the first productive work on the track is after 0200.
And that’s the problem. The last train leaves Waterloo at 0105, passing Surbiton at 0145 on its way to arriving at Southampton at 0256. The first empty coaching stock move of the day is at 0405.
The Wessex route has the shortest average access period for maintenance of the entire network.
“Every second counts in this environment,” says Network Rail spokesman James Crook. “Performance has not been at the level passengers deserve. This is such a heavily used section of railway - a quarter of a billion passenger journeys a year. We have an opportunity to improve the way we handle that.”
As passengers, we want the convenience of trains running 21 hours a day. The consequence is short, inefficient night shifts with very little time to get things done. It makes running a reliable railway difficult.
Network Rail’s choice of Hampton Court
Junction to demonstrate the new system could not have had better timing. A few days earlier, an engineering possession here overran. Instead of handing back the tracks at 0430, the contractors finished five hours later, at 0930.
It meant no trains to Waterloo from Bournemouth, Southampton, Portsmouth, Salisbury, Basingstoke, Guildford or Woking could run through the Monday morning rush hour. Rolling stock was stuck, unable to leave the Wimbledon and Clapham Junction depots.
Tens of thousands of commuters did not get to work at all. The service was wrecked for the entire day. Network Rail Chairman Sir Peter Hendy felt obliged to offer both an abject apology to passengers and a promise that this would not happen again.
NR says 3,000 working hours a year are spent undertaking manual strapping of isolations on the South Western rail network. Once fully rolled out, the new method of short-circuiting protection will take 1,400 hours a year. That gives back 1,600 hours a year, and opens up the working window by up to an extra hour every night.
In last summer’s review into poor performance on South Western Railway, Sir Michael Holden highlighted the lack of maintenance time as a contributing factor. He saw an opportunity for improvement: “The benefits of the Safe Isolations programme should reduce wasted on-track labour resource and improve the productive time available within overnight possessions.”
So, how does the new kit work? Negative Short-Circuiting Devices (NSDCs) are located near substations and operated at a control panel in a position of safety. Eventually, this will end the practice of manually applying the short-circuiting straps altogether.
Woking Track Section Manager Matt Farrell demonstrates it at the Hampton Court Junction substation, where a new control panel has been fitted to an outside wall.
“This takes us away from physically going out on track to isolate the power,” he explains.
“It makes a massive difference. A key thing to us is safety, plus it saves time for guys running around with a lot of heavy equipment.
“We can do multiple isolations from one location. If you have five or six isolations in one night, you have to send two people to each location to strap them. Here we can do all that with just one person. This panel controls about two miles between Surbiton and Esher.”
Project Manager Jack Roberts adds: “This provides a better level of protection for our staff. This is much safer and much more efficient.
“This should allow our staff to have more time out on track doing maintenance and removing defects, ultimately delivering a better service for the customer.
“On a typical midweek night possession, if this gains us 20 minutes at the start and 20 minutes at the end, that provides us with the opportunity to do a lot more work at a place where we don’t have a lot of time.”
A short distance up the track, welder Craig Fieldsend is cutting up scrap track into 30-foot lengths.
“Even doing welding it can get cold,” he says. “Minus four degrees last night, and now it’s raining a bit. I can get through 30 to 40 cuts in a four-hour job.”
Is that the most time he gets on track during a nine-hour shift?
“Yeah, about four hours work in a night - give or take. Sometimes it’s a lot less.”
The new control panels have been tested first around Guildford. The busy lines at Surbiton are a greater challenge. They are being rolled out steadily, with the Windsor Lines and the Kingston Loop next. By March 2019, 450 NSCDs will be installed, with a further 400 to follow.
Network Rail says the 20% increasing in working efficiency should mean fewer failures and a more reliable railway for passengers. And after seven consecutive years of declining performance on the lines out of Waterloo, that is certainly needed.