01.11.12
A new approach to renewals
Source: Rail Technology Magazine October/November 2012
Steve Featherstone, director of track infrastructure projects at Network Rail, describes the new track relaying system which is making the most of short possession times.
Tighter access windows for maintenance work on the railway and higher passenger demands prompted Network Rail to invest serious energy into engineering innovative solutions to renew track and ballast.
The development of a new high output track relaying system allows the railway to be kept open for longer, whilst tackling track renewal quickly and efficiently. Old track, ballast and sleepers are removed and replaced in a continuous process in record time, minimising disruption to services.
RTM spoke to Network Rail’s director of track infrastructure projects, Steve Featherstone, about the new system and its advantages.
A better way
In the past when engineering work was needed, Network Rail could take possession of the railway for a whole weekend – which is often no longer acceptable, or even feasible, given the number of passengers wishing to travel and the demands of the TOCs.
Featherstone said: “Occasionally we still have to do that, but more and more people are saying ‘Actually we want to use the weekends to travel on trains, we don’t want to be on buses’, is there a better way?”
Possessions have been reduced to typically 6-8 hours on midweek nights and slightly longer at the weekend. Renewing the railway in such constrained timescales resulted in the development of machinery such as ballast cleaners and track renewal systems (TRS).
The ballast cleaners remove around 12 inches of ballast from underneath the rails, clean and recycle it, with around half going back in, alongside 50% new ballast. The cleaner works at around 400-500 metres per hour.
This is much more efficient than traditional solutions, as it allows Network Rail to complete work in the 6-8 hour window of access.
Including time to set up and clear off the track before the start of service, Featherstone estimated they get 2 to 3 hours of good production in the middle of this window.
The TRS removes existing sleepers and track and replaces the whole lot. This typically runs at around 300 metres per hour once it’s up and running, Featherstone explained.
As a “hugely proud” professional engineer, Featherstone described the equipment as “one of the most fantastic bits of kit I have ever seen”.
He added: “It is mechanical engineering at its best: when you see it going at full tilt, it is just amazing".
Teaching the teachers
Featherstone described how Network Rail looked at existing technology around the world to achieve faster track replacement.
This involved work to have the machines specially modified to fit the gauge of the British railway, with delivery partners Amey and Colas working in a joint venture. Featherstone added, proudly, that as the team got progressively better at using the machines, French company Colas came over to learn best practice from the UK team.
He said: “Where initially France was used as the reference site for GB, it’s now the other way round: they now bring the French engineers over to the UK to understand what good looks like.”
Commenting on the direction of passenger growth and demand, he said: “It’s only going one way – we’re moving more and more passengers, and there is a desire to use the railway earlier in the morning, later at night. More and more people are getting used to the leisure travel at the weekend.
“As long as the railway keeps growing, there’s going to be increasing need for a technology such as this.”
Every minute counts
With a view to speeding up the process even further, Featherstone said that the challenge was setting up and getting the machines running at their top speed faster. This could shave time off the start and end of working time, improving efficiency and providing much faster track renewal.
The work rests upon Lean principles, to make all those extra minutes add up to produce hundreds of extra metres of production.
He said: “It’s about being creative: instead of getting 8 hours of access, we can get 8 and a half, or with the 8 hours of access we can take away the possession and isolation quicker so we can get an extra 20 minutes of full production. An extra 20 minutes of full production may be another 100 metres of track that we’ve renewed.”
The new machines are being used across the network, apart from areas using the third rail system south of the Thames. However, a pilot is taking place in this area at Christmas, to see how this could be achieved.
Featherstone said: “The technology should be capable of doing it, but we’ve just got to take it carefully and make sure we get the method statements right for using it in the third rail area.”
Compensation and cost
There are two TRSs in operation, as well as three ballast cleaning systems. Future plans will see another two ballast cleaning systems, bringing the total number of high output systems to seven.
The machines themselves represent a very expensive capital cost, but they could save money in the long term, through lower compensation for closing the railways.
Featherstone said: “I think it’s a balance of two things. If we are leaving the railway open on a Saturday and Sunday then it will save us money in compensation because obviously, generally we have engineering possessions on overnight anyway so it’s much cheaper for the access.
“It’s a question of time efficiency; it’s about doing the right thing for passengers. This is an engineering solution that will allow passengers to stay on trains: that means the railways are more attractive and more people use the railway."
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