Performance for the metre-gauge network

High-performance rail infrastructure requires sustainable maintenance. The RSRG provides end-to-end support, from analysis through to the long-term safeguarding of track quality.

The quality of the rail surface and gauge corners is a key factor in reducing noise, improving ride comfort and extending the service life of rails and track. Corrugation in particular – wave-like irregularities on the rail head running across the direction of travel – causes high dynamic loads and increased noise emissions. Against this background, the Metric Rail Grinder was developed as a compact, high-performance solution for cost-effective rail grinding on metre-gauge networks.

The aim of the project was to develop a road-rail work machine that could be used efficiently within short track possessions. Modern road-rail technology keeps on-tracking and off-tracking times to a minimum. The Metric Rail Grinder is designed for tramways, conventional railways and mountain railways with gradients of up to 60‰ and can work on both Vignole and grooved rails. In addition to removing rust layers and mill scale from newly laid rails, the machine eliminates corrugation and surface defects and enables targeted correction of the rail-head profile through precise grinding. A high-performance dust extraction system ensures clean and safe working.

The carrier vehicle is a modified compact road-rail lorry with a metre-gauge rail undercarriage. It combines high mobility with sufficient energy supply for the grinding units and can be placed on track quickly at medium-sized level crossings – a significant advantage, particularly in inner-city tram networks. Due to the limited installation space, a separate grinding module was designed and carried piggyback on the lorry. Loading and unloading take place directly on the track, with the lorry serving as the traction vehicle, energy source and control unit.

At the heart of the system is a two-axle grinding module with ten grinding stations and integrated high-performance dust extraction. Six cup-grinding units work the running surfaces on both rails, supplemented by disc-grinding stations for the gauge corners and flap-wheel grinding units for fine finishing. Based on the measured transverse profile, the grinding motors are positioned automatically at the optimum angle, while the contact pressure is controlled to ensure efficient material removal without thermally overloading the rail.

An integrated measuring system records both the transverse and longitudinal rail profiles in real time. High-frequency laser systems and sensors reveal corrugation, waves and profile deviations, allowing the operator to assess the grinding result immediately and optimise it in a targeted manner.

The Metric Rail Grinder therefore closes the gap between large rail-grinding trains and hand-guided machines. It offers transport operators an economical and flexible solution for the sustainable maintenance of rail infrastructure, the reduction of noise emissions and a significant extension of rail service life.