Curved tube track problem solved
When London Underground rail track curves, the sleepers are usually made of wood – until now, that is
The first of a new type of concrete sleeper to solve the problem of tight curves has just been produced by Cemex Rail Solutions and laid at a section of track between Whitechapel and Aldgate East.
It was previously a challenge for London Underground to produce the right type of sleeper that could guide the track around curves of less than 200 metre radius and still ensure Tube trains stayed on track.
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 longer term solution and after 12 months of development work with Cemex, a new sleeper for curves is now available.
Cemex says that 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 that 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.
The Cemex Rail Solutions factory in Somercotes, Derbyshire, is now producing three variants of the rail sleeper, with two further ones in the pipeline.
- Click here to return to the previous page
- Subscribe to our free construction newsletters
- Buy & Sell Construction Plant Machinery online with TCiTrader.co.uk. Find new, used & reconditioned Construction Equipment. Click here to view Construction Equipment Classifieds.
Download our free construction news iPhone / iPad app. Sign up to our FREE email newsletters or subscribe to our RSS feed for regular updates on the latest Construction News, Plant News, Contract News & Supplier News. The Construction Index also provides the latest Construction Tenders, Construction Market Data & Construction Law Commentary all FREE.
This article was published on 11 Aug 2016 (last updated on 11 Aug 2016).