LRQA USA - Measure the difference

Mechanical interactions

Optimising interfaces to improve performance

The interface between wheel and rail and between pantograph and catenary has a significant impact on performance, safety and cost in a rail operation. Proper analysis, understanding and management action leads to an efficient, effective and legally compliant railway system.

How we can help

Lloyd's Register has the know-how, resources and experience needed to enable rail businesses to optimise interface issues and achieve business goals. We participate in international working groups for standardization in this field and provide a range of services to our clients including:

• Advising on methods for improving wheelset quality and achieving better adhesion in the contact area including optimization of the wheel-profile and materials combination

• Analysing wheel-rail interaction and the dynamic behaviour of a train as it runs on the track

• Monitoring solutions for key vehicle / infrastructure mechanical interfaces including wheel-rail and pantograph-catenary interaction

• Development of optimised maintenance programmes based on measurement, analysis and modeling.

What are the benefits?

• Strong analysis leading to practical maintenance regimes

• Improved maintenance leading to enhanced performance, higher availability and optimised costs

• Improved track quality, life and lifecycle costs.

Recent projects

• We prepared track maintenance specifications taking rolling stock requirements as the starting point for our work. Results from measurement trains were processed using in-house developed software and combined with output from multi-body dynamics simulations to develop specifications which have been incorporated into our client's maintenance system.

• A large scale study was conducted for NedTrain to optimise life cycle costs of wheel sets. A wheel profile was designed which is less sensitive to rolling contact fatigue on the tread. Field testing showed lifetime extensions of the order of 15%. We also recommended changing the maintenance method from condition-based to preventative using the Gotcha system to catch incidents such as suddenly occurring wheel flats. This new strategy increased the life time by more than 40% and also reduced the percentage unplanned maintenance considerably.

• Lloyd's Register has developed simulation models in ADAMS/Rail which can be used to analyse the derailment safety of vehicles with small diameter wheels when travelling over switches. The extent of field testing can be reduced considerably by using these models in a so-called Virtual Test Bench.

• For the Dutch infrastructure provider ProRail, we developed concepts to control rolling contact fatigue (RCF). Practical inspection and maintenance concepts were developed and ways of reducing the initiation of RCF were investigated through numerical modelling and field tests.

• We have carried out a study in the Netherlands into the reasons and conditions for low adhesion. Working with three universities, we developed, tested and implemented various measures to mitigate low adhesion.