Stretched rails bridge gaps

Broken rails can kill – as the beleaguered rail industry in the UK knows to its cost. US-based Harsco Track Technologies is patenting a technique (US 6 515 249) that avoids the problems that arise when faulty rail sections are cut out and the gap filled with a repair strip. The aim is to preserve the “neutral rail temperature” – the ambient temperature at which the rail was installed and set under tension. Filling a gap with a new piece of rail introduces a different NRT, leading to mismatched expansion and contraction on hot and cold days. Harsco’s answer is…