It was a challenge for London Underground to produce the right type of sleeper that could guide the track around tight curves, less than 200 metre radius, whilst ensuring Tube trains stayed on track. The first of a new type of concrete sleeper to solve the problem has just been produced by CEMEX Rail Solutions in partnership with London Underground and laid at a section of track between Whitechapel and Aldgate East.
Sleepers designed for curves were previously made of timber, which tends to shrink over time and therefore can affect the gauge of the track. London Underground wanted a more long term solution and after 12 months of development working in partnership with CEMEX, a new sleeper for curves is available.
The main challenge was how to attach the cast iron base plate to the sleeper? This would normally be done by casting plastic dowels into the concrete to allow the base plate to be bolted down. Analysis by Durham University highlighted complications when using standard attachment methods, related to the forces in pre-stressed concrete which may induce cracking.
Replacement of plastic inserts normally used for attachment of conductor pots by steel inserts and reinforcement around the plastic dowells, adopted from industry practice in Germany, has significantly reduced the risk of any possible cracking.
Currently there are three variants of the check rail sleeper all produced at the CEMEX Rail Solutions factory in Somercotes, Derbyshire with two further ones in the pipeline.
Next time you are in a Tube on this section of the track going round a bend, it’s thanks to the CEMEX sleeper.
Notes to editors:
For further CEMEX details contact Elizabeth Young; email: Elizabeth.firstname.lastname@example.org t: 01932 583214.
- Follow us on Twitter@CEMEX_UK and for further information go to cemex.co.uk
- Helping to build a Great Britain – CEMEX’s vision is to help build a greater Britain by providing solutions to construction problems through our innovative building materials, our expertise, our understanding of the construction issues and our people.We aim to create the best service and the best solutions for a better future.
- About CEMEX: CEMEX is a global manufacturer of building materials and the biggest Mexican investor in the UK, with 3,000 people employed across 450 sites nationwide. In this country, we are a leading provider of aggregates, cement, ready-mixed concrete and rail sleepers with annual sales of around £1 billion.