The most fundamental part of any rail transport system are the rails that make up the permanent way. These provide the interface with which locomotives engage their tractive power to accelerate and act as the steering mechanism for rolling stock.

Steel has been used in the manufacture of rails since the first were laid in Derby in 1857 (Marshall, 1979). Unlike much of the other uses of structural steel, the rails used in permanent way are subject to very high stresses, and as a result the quality of the steel has to be similarly high, eliminating defects and irregularities that may result in stress concentrations and/or rail failure.

There have been many developments in the design of steel rails over the years, and as a result there are dozens of rail designs in use across branch, minor and heritage lines in Britain.

When considering the limits for use of recycled rail, three primary topics emerge: Rail types, wear and failure.

Each of these sections is considered in greater detail on their respective pages (click on the links to go to these) and will be expanded and updated as the literature review progresses and as the direction for any physical testing is established.