Railmeasurement - Rail Corrugation and Acoustic-Roughness Measurement Equipment

RailMeasurement Ltd (RML) is one of the largest suppliers to the railway industry worldwide of equipment to measure rail corrugation and acoustic roughness. We supply validated equipment to measure corrugation at all speeds.

Rail corrugation analysis trolley

RML's corrugation analysis trolley (CAT) is used by railway systems, suppliers, grinding contractors, consultants and universities worldwide for many purposes, including routine quality control of rail grinding, monitoring of corrugation test sites, and research into rail corrugation and its mitigation.

The latest CAT 3 can be used on both grooved and conventional flat-bottomed rails. Simple lateral adjustment of the measuring head is possible to within 10mm of the gauge and field faces of the rail. One person can transport the CAT from site to site in a wheeled instrument case, plug it into a laptop using a USB cable, and take measurements within minutes.

Rail corrugation measuring equipment and rail grinding trains

RML manufactures corrugation-measuring equipment for reprofiling vehicles, in particular grinding trains. The rail corrugation analyser (RCA), measures sufficiently accurately at speeds of up to 10km/hr to demonstrate compliance with EN13231-3:2006, and is used routinely by grinding crews. This equipment is also available as a self-contained measuring bogie that can be moved from one train to another, or attached to a hy-rail vehicle, battery locomotive or the like to undertake routine corrugation surveys.

Medium speed corrugation measurement

RML's medium speed RCA is designed for use on a hi-rail vehicle at typical speeds of 40km/h. Both long wavelength (500mm-1500mm) and short wavelength corrugation can be measured to an accuracy of microns.

High-speed rail corrugation-measuring equipment and acoustic measurement

RML's high-speed RCA (HSRCA) is a system to measure corrugation and acoustic roughness on rails at normal operating speeds, typically in excess of 80km/hr. Lower speed measurement is also possible with reduced (but nevertheless extremely high) accuracy.

Validation of rail measuring equipment

One of the areas in which RML has led the industry is in validation of measuring equipment. We developed a method, when none was available, that could be used by any supplier to demonstrate accuracy of equipment such as the CAT in different wavelength ranges.

This technique was openly published and subsequently included as an Annex to the European Standard for reprofiling rails (EN13231-3:2006). It specifies a higher accuracy for shorter wavelengths than for longer wavelengths, which reflects the physical reality that significant short-wavelength irregularities are smaller than longer wavelength irregularities. A calibration certificate is issued with all CATs stating the accuracy found by this method.

We have also participated in an independent 'road test', the protocol for acoustic roughness measurement in EN 15610:2009.

RCAs, MSRCAs and the HSRCA are validated by comparing measurements made with them to measurements to those made using a CAT.

Processing software for rails' transverse-profile measurements

RML also produces modular software to process measurements of a rail's transverse profile and produce information such as correlation with a specified transverse profile. A summary grinding compliance index (GCI) is calculated which can, if desired, include the influence of corrugation. A rail quality index (RQI) can also be calculated and provides a simple summary of rail wear, transverse profile and corrugation.

RailMeasurement's clients include Alstom, Banverket, Hong Kong MTRC, IRT (Monash University), Loram, MetroNapoli, Metronet (London Underground), Portec/Kelsan, Queensland National, Schweerbau, Sumitomo, Toronto Transit Commission and Wiener Linien.