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CAT, RCA and HSRCA information updates

Mon, 24 Oct 2011 00:00:00 +0100

The CAT, RCA and HSRCA information pages have been updated with all the latest information and news about those products.

MSRCA Information Update

Tue, 27 Sep 2011 17:00:00 +0100

The MSRCA information page has been updated. Click here for the latest information on our hi-rail based system for corrugation and roughness measurement.

RailMeasurement in China

Sun, 31 Jul 2011 15:19:59 +0100

During July, Bonanza Rail Technology Co Ltd (BRT) became the agent for RailMeasurement Ltd in China. A CAT has been supplied to Beijing Metro (BJ MTR), who also use RML’s RCAs on their rail grinding trains. Dr Grassie of RML gave a presentation on this equipment and on rail corrugation more generally to representatives of BJ MTR, to local railway construction and design companies and to staff of Beijing Jiaotong University in July. Please contact Stuart Grassie at RailMeasurement Ltd (stuart.grassie@railmeasurement.com) or Hugo Zhang at BRT directly for more information (hugo@brailtec.com).

Measuring squats and studs

Mon, 20 Jun 2011 00:00:00 +0100

In June 2011, Dr Grassie presented a paper at the International Heavy Haul Conference in Calgary on so-called “squat” and “stud” type rail defects. A PDF of the presentation can be found here. Page 17 of the presentation shows measurements of the irregularities presented by “stud” defects on both rails. Although the MSRCA was designed to measure corrugation, we have submitted a proposal to identify the location and quantify the severity of discrete irregularities such as squats and studs, which are prevalent in some locations on some types of track. Two papers on these defects by Dr Grassie and his co-authors have been accepted for publication by the Institution of Mechanical Engineers and should appear early in 2012.

Measuring microns at 50km/h

Fri, 13 May 2011 00:00:00 +0100

In May 2011, comprehensive testing was undertaken of RML’s hi-rail based MSRCA corrugation system, which is designed to measure corrugation to an accuracy of microns at speeds of up to 50km/h. Correlation of MSRCA at 50km/h with CAT measurements (moving average of RMS amplitude in 30-100mm wavelength range, percentage exceedence graph and one-third-octave spectra) over 500m of rail is shown below. Correlation is very impressive.

MSRCA data from 50km/h run correlates well with CAT data

RailMeasurement increases awareness of wheel/rail noise, roughness and corrugation

Tue, 03 May 2011 00:00:00 +0100

In May 2011, Dr Grassie was a member of a panel on wheel/rail noise at the Rail Transit seminar organised by ARM Corporation in Chicago. His presentation on wheel/rail noise, rail grinding, measurement and specifications can be found here. This contains several sets of measurements of rail corrugation and acoustic roughness made with RML’s CAT and RCA on different types of track worldwide, before and after reprofiling.

CAT Update

Mon, 14 Mar 2011 00:00:00 +0000

During the first part of 2011 RailMeasurement Ltd (RML) have modified the latest CAT 3 to include a telescopic stabilising pole to accommodate different gauges. Software has been updated to improve identification of areas that require reprofiling.

RCA mounted on Japanese rail grinder

Mon, 28 Feb 2011 00:00:00 +0000

During February 2011, RML installed an RCA on a Harsco rail grinder operated by Sumitomo Metal Technology Inc (SMT) in Japan. SMT are RML’s agents in Japan and had previously used a corrugation system of their own design. SMT were very impressed by the RCA’s performance and by its ability to measure not only short wavelength corrugation but also corrugation of over 1m wavelength. Henceforth SMT will use RML equipment on the rail grinders that they operate and supply unless the client wishes otherwise.

Stuart Grassie presents on rail corrugation and wheel/rail noise

Mon, 24 Jan 2011 00:00:00 +0000

In January 2011, Dr Grassie gave a presentation on rail corrugation and wheel/rail noise to the TRB Annual Conference in Washington, DC. The presentation is available here. This contains excellent measurements from colleagues worldwide using RML equipment, including RCA measurements on p22 showing not only how corrugation is reduced during grinding to a level of less than 4 microns RMS but also that such minute levels can be measured reliably using RML equipment during the reprofiling operation itself and from a grinding train. CAT measurements made by colleagues at SWJTU in Chengdu (page 21) show how quickly corrugation develops again at this site. Measurements of corrugation and ground-borne noise, made by colleagues at London Underground, are also included that show how a reduction in low frequency noise correlates with the reduction in longer wavelength corrugation resulting from reprofiling.

RailMeasurement introduces the Medium Speed Rail Corrugation analyser (MSRCA)

Tue, 21 Sep 2010 09:00:00 +0100

The MSRCA is a corrugation measurement system designed to be fitted on a hi-rail vehicle. Running at speeds up to 40kph, the system provides measurement capabilities suitable for grinding surveys and similar. A data sheet is available on our download page.

RailMeasurement Update

Mon, 01 Mar 2010 09:00:00 +0000

During 2009 RML delivered corrugation measuring equipment to run on a hy-rail vehicle, which has been equipped to work as a pre- and post-grind inspection vehicle for a grinding contract on ARTC's standard gauge network in Australia. This equipment, known so far as the MSRCA (Medium Speed RCA), is intended to measure corrugation over a wide wavelength range (up to 1500mm wavelength) at a speed of 40km/h and with an accuracy of microns. At present (spring 2010) the MSRCA is undergoing testing and excellent correlation with the CAT has been demonstrated at up to 20km/h.

At the request of a good customer, RML developed software to calculate the severity of dipped and peaked welds from CAT measurements. This appears to work very well provided corrugation has not already propagated from the weld. However, when this occurs, the software has some trouble differentiating the dip or peak, whose severity is measured manually using a 1m straight edge, from the resulting long wave corrugation. We would be extremely interested in taking this study further with anyone who was interested in developing a more routine and reliable method of measuring the severity of dipped and peaked welds. The RCA or MSRCA is probably a better instrument for this in the longer term, since it would be possible to measure at speeds of several km/h if not tens of km/h. The CAT would still be appropriate for measuring short lengths of track and a few welds.

RailMeasurement Update

Tue, 01 Dec 2009 09:00:00 +0000

In November 2009 RML undertook a week of comprehensive testing with SNCF of RML's HSRCA system. SNCF were interested in the HSRCA as a possible way of undertaking "noise mapping" of the French railway system. The week included thorough tests of repeatability and reproducibility of the system over track with different trackforms and different levels of corrugation, and an assessment of "accuracy" over several sites which had been measured using straight-edge based equipment and two sites that had also been measured with a CAT. Acoustic roughness of the line from Paris to the test area in the south of France and back was also measured, producing one-third octave spectra of railhead roughness in ISO3095 / EN15610 format for 100m lengths of both rails every 10m. The results were extremely good, and although not yet published openly a sample of results is shown in the abstract for a paper that has been accepted for poster presentation at the 10th International Workshop on Railway Noise in Yokohama in October 2010 (available here).

During 2009 RML introduced the Mark 3 CAT, which is designed specifically to measure both conventional flat-bottomed (Vignole) rail and also grooved rail which is severely worn and deformed, and possibly also deeply embedded in the street below the level of the adjacent tarmac. It is also now even easier to adjust the lateral position of the measuring head right up to within 10mm of the gauge and field faces of the rail. We have found that CATs are increasingly being bought to measure acoustic roughness rather than corrugation. It is probably the least expensive equipment of its type available, yet in many ways also (as a client told us):

"The CAT is unique"

The capabilities of the CAT for measurement of corrugation and acoustic roughness are illustrated in an article that appeared in April's edition of International Railway Journal. This contains measurements from a variety of railway systems worldwide, which have been supplied to RML by users. Interesting differences between different types of railway system are apparent that have not (to our knowledge) been noted before, largely because no instrument of sufficient accuracy has previously been available and used as widely for measurements of this type. This article also shows the requirements for residual corrugation in the European reprofiling standard, EN13231-3:2006, as a one-third octave spectrum and compares this to the spectrum in the acoustics standards ISO3095 / EN15610. Since the requirements are very similar, it follows that an instrument to demonstrate compliance with EN13231-3:2006 should be of similar accuracy to one that is used to demonstrate compliance with ISO 3095 / EN15610. Fortunately we can supply you with such equipment, even to work at 10km/h or more on a reprofiling train or hy-rail. This helps the supplier of reprofiling services to know that they are reprofiling track to a high standard, and the railway system to know that the contractor is doing what they require.