’WEAR IS HEALTHY, but uncontrolled wear is not.’ Richard Keefe, Infrastructure Engineering Manager for MTR Corp in Hong Kong, was referring to the management of rail deterioration on one of the world’s busiest metros. Intriguingly, the model developed for rail management on Hong Kong’s MTR had been prescribed by BHP, with which MTR had been working since 1989. The partnership with an operator whose expertise was in heavy haul freight had proved to be particularly fruitful.
Keefe was speaking at the Railway Engineering 2001 conference in London on April 30 - May 1, organised by ECS Publications and sponsored by Railway Gazette International. The event attracted nearly 300 delegates from 18 countries. Keefe’s was among several papers that won considerable attention, not least because of the current interest in rail deterioration in Britain following the derailment at Hatfield last October (p413).
Problems with rail on the MTR network had led to studies of corrugations and shelling, the result being the development of a structured approach that Keefe said ’looked at everything’. Areas investigated included wheel and rail profiles, lubrication, use of rail pads, grinding cycles and types of rail. The resulting rail management programme had allowed MTR to halve the amount of rail being replaced on the 42 route-km network since 1992, said Keefe, generating savings in materials and manpower that ’paid for the investment cost of a 32-stone grinding train’ and more besides.
Rail shelling had been cut by 85%, and the rate of growth of corrugations had been reduced. The greatest benefits were on sharp curves, where there had been ’almost uncontrollable corrugation growth’. Keefe explained that use of high-performance heat-treated rail needed ’to be managed in a high performance way’ in the same way that oil must be changed frequently with a sports car. The programme meant that ’we are in control of deterioration rates, with side and top wear at similar rates - this means that you can renew [the rail] at the same time when both types of wear reach the same point.’ Similarly, careful management of wheel and rail profiles had seen flange wear reduced by 67%.
Keefe also explained the mystery of high wheel and rail wear rates on Hong Kong’s 34 km Airport Railway, which opened in July 1998. Soon afterwards, track engineers discovered high rates of wear, which Keefe said were ’10 to 20 times more than expected’ - this despite efforts to match the design of rolling stock and infrastructure for optimum performance. The problem turned out to be lack of lubrication, as the supplier had not fitted the required on-board lubricators to the rolling stock. There were apparently good reasons for this decision at the time, but the ensuing wear demanded rapid intervention.
In the short term, MTR introduced manual lubrication of curves, but on-board lubricators were soon fitted, reducing wear to levels similar to those on the urban network. The lesson was that ’the wheel/rail interface has to be actively managed’, and that critical success factors included taking a holistic approach, having trust and patience, and making continuous improvements. Keefe said that trains for MTR’s Tseung Kwan O extension would have lubricators fitted from day one.
Systems approach vital
Seeing the railway as a whole system was also seen as essential by Railtrack’s Director, Railway Systems, Andrew Doherty. Although much of what he said applied only to the uniquely structured rail industry in Britain, there were lessons for other railways contemplating restructuring. He warned delegates that there had been ’a lack of cross-industry processes’ in Britain and noted that a systems approach was essential for the future.
Describing Railtrack’s approach to asset management, Doherty said that that the company’s asset register included around one million significant assets, but in relation to asset management policies problems had arisen because ’there has been a fair bit of loss of knowledge in the industry in the last few years’.
Among changes likely to be made on the Railtrack network is the introduction of improved pointwork. This would need to be ’tamperable’, while prototype turnouts featuring remote condition monitoring had already installed at Nunhead in Railtrack’s Southern Zone.
Signalling philosophy too is set to change, and here Doherty is looking for equipment and policies that ’keep the railway working’ when there is a failure, rather than simply shutting it down. The policy of what he called ’graceful degradation’ is not new, and many metros already have similar processes in place. n