[2025] UKUT 00138 (LC)

Railway track is formed of two rails attached to sleepers which hold them the correct distance apart. Beneath the sleepers is ballast, made of small stones. There are some 20,000 miles of railway in the UK, and about 26 million sleepers. Sleepers used to be made of timber, but most of those have now been replaced; a few are made of steel; the vast majority are made of concrete. New materials for making sleepers, including recycled plastic, are being developed with a view to minimising the carbon footprint of the network. The life-span of concrete sleepers is not infinite and so Network Rail (“NR”), which since its creation in 2002 has owned the railway track in Great Britain and is required to maintain it, requires a constant supply of sleepers, mostly for the cyclical replacement of all the sleepers in the network and a small proportion for new track. The size of that requirement has varied over time and is now at an all-time low, and the reasons for that are not agreed; nor do the experts agree how many sleepers NR will require in the future. There are other customers for sleepers, notably Transport for London Limited, but NR’s purchases constitute more than 90% of the market in Great Britain. Conventional sleepers have not been used in the construction of HS2, and therefore that project has had no effect on the market in sleepers.

The vast majority – about 95% – of sleepers used in Great Britain are of the G44 and the slightly longer EG47 type. The remaining 5% is made up of a number of specialist sleepers for use where sizing is non-standard (for example in tunnels and viaducts). In recent years NR has required some sleepers to be fitted with Under Sleeper Pads (“USPs”); these are rubber-based pads fixed to the underside of the sleeper during the manufacturing process which cushion the weight of the train and therefore reduce damage to the ballast. Mr Allen said that while NR would like 50% of sleepers to have USPs, they are more expensive and only about 16% of sleepers are made with them.

Track is attached to the sleepers by means of a clip, and when the clip works loose the sleeper has to be replaced. The “Pandrol” clip was introduced in 1963, and according to Mr Heubeck it “solved the problem of the long-term stability of the rail secured to the sleeper”; by 1969 all sleepers were fitted with Pandrol clips.

Nevertheless, how long a sleeper lasts is variable; the sleepers experts disagreed about their usual lifespan. Mr Jarvis told us that it is generally reckoned to be 30 years, while Mr Heubeck for the authority told us that they could last 60 years or more. We say more about that disagreement later, but both views demonstrate that sleepers are needed in substantial quantities for maintenance. Mr Jarvis’s evidence was that NR reckoned on an average of 750,000 a year, and he recalled one year when it purchased 930,000. Neither of those figures is agreed, and NR’s requirement has been much lower in recent years, reaching an (agreed) all-time low of 307,000 or so in the last twelve months.