Freight blamed for cracking new rails

Railtrack may have to build a separate rail network to carry freight trains following evidence that new rail laid less than a year ago is cracking under the weight of goods wagons.

Chairman of railtrack, Gerald Corbett, told the CBI conference on Tuesday that he was seeking urgent technical advice to discover the cause of ‘gauge corner cracking’. But he singled out the extra strain imposed by freight trains as a possibility. And rail experts told The Engineer that inferior US-designed bogies on freight wagons introduced since privatisation were a factor in causing the damage.

Corbett revealed that cracks were discovered in track laid less than a year ago when they were inspected last weekend during the massive safety audit following the Hatfield accident. And he said the company was working with experts from Imperial College and Nottingham University to look into the problem.

Corbett said the relationship between train wheel and track was ‘absolutely critical’ in solving the issue, and pointed to the heavier strain placed on rails by freight axles.The findings could have huge implications for government plans to move freight on to the railways. ‘We may see ourselves moving towards dedicated freight lines because of the wheel/rail interface issue,’ Corbett said.

Dr Felix Schmidt, senior lecturer in rail systems engineering at Sheffield University, told The Engineer there were several possible reasons behind the rise in gauge corner cracking, such as an increase in traffic. Also new head-hardened rail meant that surface cracks caused by rolling contact fatigue were no longer worn away.

Another factor was the heavier loads imposed on track by US-designed bogies introduced on freight wagons since privatisation. Schmidt said the US three-piece bogie had poor ride quality, but cost only £9,000 compared with the £11,000–£18,000 for UK designs such as Powell Duffryn’s ‘track friendly’ TF25 bogie. ‘They are cheaper but not as cost-effective,’ Schmidt said.

Operator English, Welsh & Scottish Railways, which uses the US bogie, has criticised UK rail suppliers for producing expensive, unreliable and costly to maintain equipment.Schmidt also suggested that Railtrack’s suggestion of a dedicated freight network was possible. There was space to reinstate a third or fourth line next to existing track on many key main lines at reasonable cost, he said. This could provide a separate line for freight and slow traffic while keeping the existing track for high speed services.