Trimming the cost of track inspection - Mer Mec S.p.a.

InsPECTION | INFRASTRUCTUReTrimming the cost oftrack inspectionMONITORING Gaining access to busy tracks to check for defects is increasingly difficult and expensive,but legislation such as the Railway Safety Directive in Europe enforces the effective monitoring of bothinfrastructure and rolling stock. Cheaper alternatives to conventional track inspection methods arestarting to emerge, finds Murray Hughes.MerMec hassupplied itsrange of Rog e rself-propelledinspection carsto infrastructuremanagers inseveral countriesincludingSwitzerland,Norway andSouth Korea.Photo: MerMecDivision of traditional railwaysinto operating andinfrastructure companieshas tended to exacerbatethe divide between the management ofrolling stock and fixed assets, althougheven in national railways the responsibilitieswere often split between differentdepartments. It can be argued thatthe split stemmed partly from a lack ofhard evidence or data to support theunderlying dependence between thebehaviour, or deterioration, of the twogroups of assets, despite the fact that itwas common knowledge among everyoneinvolved that track and trainswere indeed inter-dependent.Today, there is growing recognitionof the interaction of track and trainsin terms of wear and deterioration,and in some cases senior managementrecognises the benefits of anintegrated approach. On heavy haulrailways, for example, co-operation isgenerally implicit, with the chief engineerholding responsibility for bothtrack and trains.Legislative frameworkMonitoring the condition of infrastructureand rolling stock becomesmore significant under the EuropeanUnion’s Railway Safety Directive. Responsibilityfor ensuring that safetyis maintained now rests with the infrastructuremanager, the operator,the vehicle owner, the ‘keeper’ ortechnical manager of the vehicle, andalso with the person or organisationresponsible for loading it. All havetasks and responsibilities laid down innational and international legislationas well as in regulations and privatecontracts.Fulfilling these different tasks withoutincurring disproportionate costwill increasingly rely on remote monitoringof the status of the asset, be ittrack, catenary or rolling stock — andits interaction. This brings into playinfrastructure measuring equipmentas well as automated wayside measuringsystems.Track inspection trains or singleinspection cars have been widely usedto measure numerous track parametersand ensure that they remainwithin specified tolerances, either forreasons of safety or for ride comfort.In some cases the trains run at similarspeeds to commercial traffic, andamong the most sophisticated vehiclesin service are the Doctor Yellowtrainsets in Japan, RFI’s Archimede inItaly and Network Rail’s New MeasurementTrain in the UK.Inspection vehicles collect hugeamounts of data. This can be processedon board, stored for later downloadingor transmitted to a remoteprocessing centre. The resulting informationis used to determine if urgentmaintenance or repair work is requiredand also to plan maintenancein the short or long term as well asto check the effectiveness of previousintervention. Infrastructure managerscan use the information to build a detailedpicture of the state of track andrelated equipment across the network,allowing trends to be identified andRailway Gazette International | November 2010 43

InsPECTION | INFRASTRUCTUReRail in the UK.Remote monitoring is also beingtried in the USA. Whereas the FederalRailroad Administration uses a fleetof dedicated geometry cars to inspectaround 50 000 km of track every year— with plans to step up inspectionsto reach 160 000 km a year — otherorganisations are experimenting withvarious forms of unattended monitoring.Union Pacific has 22 ultrasonicrail flaw detection vehicles whichwere joined five years ago by a pair ofEC-5 track geometry inspection carssupplied by Plasser & Theurer.More recently, UP has fitted remotemonitoring equipment on 10locomotives and on a coal hopper tocheck the condition of its busiest coalroutes. Supplied by Ensco, the equipmentmonitors vehicle-track interactionin order to detect deviationsfrom normal behaviour that may becaused by track defects. High verticalimpacts, for example, may be causedby problems at rail joints or by otherforms of rail damage. The equipmentwas successful enough for UP to planan order for another 10 units, nine ofwhich would be fitted to locomotivesand one to another coal car.ExperienceThe UK is one country where remoteinspection has been appliedsuccessfully, and several systems havebeen installed in revenue vehicles. Inthe case of MerMec equipment, theinspection devices automatically collectand transfer track geometry datain the form of a series of raw data filesvia wi-fi to network access points instations. From these access points,data is passed via the internet to afile server located in Network Rail’sdata centre in Derby, where MerMechas provided software that automaticallydetects the arrival of new datafiles from the vehicles and convertsthe raw instrument data into trackgeometry measurement files.Network Rail also uses equipmentfrom DeltaRail, which has suppliedits TracklineTwo unattended trackgeometry recording equipment. Oneset was fitted for a year of trials onNetwork Rail’s New MeasurementTrain, and during October 2010 thiswas being used to collect data on themain line network while the train’strack recording coach underwentmaintenance for four to six weeks.Recording various parameters usingnon-contact optical and inertialbasedequipment, TracklineTwoconsists of two bogie-mounted instrumentationpods with high-precisioncameras and dual laser technology.The data is passed to a processorhub that can be accommodated undera seat or in a luggage rack, andthis is then sent via wi-fi or othermeans to an office-based asset managementsystem.Another TracklineTwo packagefitted to a multi-purpose test vehicleused by Network Rail is intendedprimarily for inspection of switchesand crossings and tracks in depots.The same vehicle also has a videoinspection pack. Adrian Golby ofDeltaRail confirms that the technologyof remote inspection is ‘still inits infancy in terms of moving awayfrom track recording cars, and this isquite market dependent.‘The first generation of remote trackgeometry inspection systems havein some cases proved disappointingin reliability and performance, butDeltaRail has now made significantsteps in improving performance andreducing maintenance and calibrationrequirements through the integrationof the necessary subsystemsinto its robust modular inspectionpods and processor. This should stimulatethe development of the marketfor remote inspection systems’.Pointing out that some railways donot make regular track inspections atall, Golby says that remote inspectionposes the problem of handling hugeamounts of data, suggesting that thismay be a deterrent to wider adoptionof the technology.DeltaRail therefore provides anintegrated suite of products includingTracklineTwo, the TrackMastermaintenance support system and theVampire vehicle dynamics modellingtool, to collect and transformdata into useful information. Theintegrated capability can be used topredict degradation, identify trendsin track geometry and develop maintenanceplans. In some cases savingsof up to 40% of tamping costs havebeen reported, the company says.Golby says the objective is to helpreduce maintenance costs by turningdata into information that addsvalue.Remote inspection equipment canbe installed on any type of vehicle,and an ‘add-on’ inspection modulehas been fitted to a multi-purposetrack and overhead line maintenancevehicle supplied by Windhoff BahnundAnlagentechnik for use on HighSpeed 1 in the UK. A similar trackinspection module has also been installedin a Windhoff multi-purposemaintenance vehicle operated on theUK’s West Coast Main Line.Some of Windhoff ’s latest multipurposevehicles have been designedspecifically to accept inspectionmodules, and the company is keepinga close eye on developments inseveral countries.Raildiagnostics of Ferrara in Italyis another supplier of video trackEurailscoutdisplayed thisunmannedlocomotivehauledinspectiontrolley atInnoTrans inBerlin, wherevisitors expressedconsiderableinterest.Railway Gazette International | November 2010 45

INFRASTRUCTURE | InsPECTIONAlignment verificationinspection equipment that can beinstalled on any vehicle. Productsinclude the Optotrack six-camera/laser system to measure rail profileand wear as well as corrugations,alignment, gauge, twist and cant.There seems little doubt that remoteinspection is becoming morewidely accepted, but as Golby asserts,the railway industry remains conservativeand a change such as thisis bound to take time. MerMec goesas far as to say that remote monitoringwill soon become a ‘commodity’with monitoring systems routinely‘embedded’ in rolling stock.Inspection wagon optionThis view is not universally held,however, and Eurailscout DirectorAad van der Zouwen believes that useGeometry: Swiss company Amberg Technologies originallyentered the rail business with equipment that measured tunneland bridge profiles, but since 2002 it has been developing itsGRP3000 systems for measuring track geometry and evaluatingclearances. Together with its GRP System FX surveying platform,the company now offers a range of software and measurementequipment that is used to perform a variety of railway surveyingtasks that include checking track geometry and verifying thealignment of slab track.Amberg worked extensively in Italy to verify the alignmentsof the ballasted track on RFI’s recently-completed high speednetwork. Similar work was carried out in Spain, while morerecently the company has secured a considerable amount ofwork in China where its equipment is used to check the alignmentof slab track on the rapidly expanding network of highspeed lines. Here the vertical alignment is required to meet atolerance of ±1 mm.The first application in China was on the Beijing – Tianjinhigh speed line, where Amberg equipment was used to checkthe positioning of 24 high speed turnouts and for geometricacceptance of the whole 114 km route. Eight GRP1000 slab trackmeasuring systems were deployed along the line, deliveringthree-dimensional track co-ordinates in real time and checkinggauge and cant measurements. Similar equipment is being usedon the Beijing – Shanghai high speed line where tracklaying iswell advanced.According to Heiko Barthold, Rail Systems Product Manager,the latest equipment uses a digital version of the establishedlong-chord measuring principle. This offers the potential to save70% of the cost of manual surveying, he says. lAmberg measuring equipment is being used to verify thetrack alignment on China’s high speed lines before theyare commissioned for commercial service.of a conventional inspection train orspecialist vehicle is preferable to remotemonitoring. He considers thatsensitive track recording equipmentis too specialised to be entrusted tothe harsh environment of commercialoperations, adding that access tothe equipment for maintenance mayalso be more difficult.Based at Amersfoort in the Netherlands,Eurailscout offers infrastructureinspection and analysisservices right across Europe. It usesinspection trains such as the UST02and UST96 to measure track and railcondition at up to 100 km/h. Morerecent vehicles such as the UFM160can take measurements while operatingat 160 km/h.Eurailscout’s range of measuringequipment includes video for trackdefect detection, laser-based opticalgauging and inertial systems fortrack geometry measurement, laserequipment to identify rail corrugation,ultrasonic devices for detectionof rail damage such as squats orsplit heads and inductive eddy-currenttests for head check detection.Ground-penetrating radar is alsoavailable to check ballast conditionand to identify wet spots.Given that outsourcing inspectionservices is cheaper than purchasingdedicated inspection cars, Eurailscout’svehicles see service in many countries,with one inspection train visitingBelgium, Germany, Norway,Slovenia, Switzerland and Turkey,for example.Nevertheless, as van der Zouwenpoints out, the cost of a train fittedwith signalling and train controlequipment for use in different countriesis high. A lower-cost alternativeon offer is the MUV unmanned twoaxleinspection wagon, the first ofwhich was completed in time for displayat InnoTrans in September. TheMUV was due to be shipped to RFIimmediately after the exhibition, anda second vehicle has already been ordered.Tests with a MUV have beenrequested in France, and two moreinspection wagons are to be completedby the end of 2011.The first MUV is intended to inspectswitches and crossings, but itcan also be used on plain line. Witha 4 m wheelbase, it is designed tobe hauled by a locomotive at up to40 km/h in measuring mode, takingmeasurements at intervals of 18 mm.Van der Zouwen says that once thelocomotive crew has been briefed onoperation of the wagon, no furtherintervention is required.Fitted with laser and optical measuringequipment, the MUV collectsdata that is transmitted to Eurailscout’sheadquarters for processing. Accordingto van der Zouwen, the inspectionwagon is small enough tobe shipped to worksites by lorry, acheaper option than obtaining approvalsfor a self-propelled inspectiontrain to run through differentcountries. Another advantage is thatthe wagon can be converted for useon track of different gauges.The next step, says van der Zouwen,will be to develop a versionwith ultrasonic inspection equipment,but this, he suggests, will requirethe presence of staff on boardwhile the machine is operating.Road-rail vehiclesAnother option is to use road-rail inspectionvehicles that only occupy thetracks while they are actually working.This service is offered by Zeta-Tech inNorth America, whose range of inspectionsystems includes hand-helddevices such as TieInspect for sleeperinspection and TrackInspect for trackinspection.The company’s TrackSafe realtimevehicle-track interaction safetyanalysis system can be used in conjunctionwith onboard track geometrymeasurement to identify locationswhere unsafe vehicle dynamicbehaviour is generated. The equipmentchecks the basic parametersof gauge, surface, alignment, crossleveland twist against permissibletolerances, but it can also measureother parameters.TrackSafe has the ability to simulatesimultaneously the behaviourof several types of vehicle at differentspeeds. It uses the geometrymeasurements to generate responsepredictions for car body bounce,roll angle, pitch angle, vertical accelerationand vertical wheel loads,and these can be calculated for anyindividual segment of track. Usingestablished thresholds for thesevalues, response predictions are assessedto determine if the vehicle iswell behaved, or if it exhibits adversedynamic behaviour and derailmentpotential.Having identified locations withhigh risk, Tracksafe can then allocatethem a priority, giving maintenancemanagers the information neededto take decisions on the need for repairsor other action. l46 Railway Gazette International | November 2010