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Rail Engineer • April 2015
Driving HIGH PERFORMANCE TRACK DANIEL PYKE
Steel rails form a fundamental part of our industry - which is named after them - and their performance is vital to operating a safe and efficient railway...
Over many centuries, rail materials have changed to give improved performance in terms of rail life and load carrying ability. From humble beginnings of wooden rails eventually strapped with iron to improve their life, the materials used have developed from wood, to cast iron, to wrought iron and eventually steel rails which form the basis of our railway networks today. Steel rails themselves have developed over many decades and continue to do so in the quest for better performance. This article hopefully describes some of my experiences taking an idea from a coffee machine conversation to a product supporting a 125mph buffet car.
The need for better steel Historically, the management of rolling contact fatigue (RCF), or head checks for European readers, has presented a challenge for many rail networks across the world. The use of longer-lasting, more wear-resistant rails increased the relevance of this degradation mechanism and its importance was crystallised by the incident at Hatfield in October 2000. Managing RCF is both costly and time consuming in an industry that has a drive towards lower maintenance costs, shorter maintenance windows and greater track availability. In response to the industry needs of doing more with less, Tata Steel set out to design a new rail steel that delivered improved rail life whilst also minimising maintenance requirements. This rail steel should be both resistant to wear and also resistant to RCF as a large proportion of track maintenance budget is focused around rail remediation and replacement due to these issues. The rail steel developed to address this need is called HP335, a High Performance rail steel with a minimum Brinell hardness of 335HB, (cf. standard R260 grade with a minimum hardness of 260HB). Introducing a new and fundamentally critical product to the rail industry, which is traditionally rather risk averse, is always going to be a challenge. However, working in close partnership with Network Rail and other customers, Tata Steel has brought HP335 into use to
To find out more about our work at Blackfriars visit railsignage.com
demonstrate that large cost savings can be made by using the right rail in the right place. Within two years of track testing, HP335 has achieved full product approval. In less than five years, it has commenced incorporation into both Network Rail and European rail standards and, most importantly, around 600km of it is now in use, delivering large life cycle cost savings. These equate to a seven-figure cost saving per year, delivered through reduced inspection and maintenance requirements and, of course,