Light rail, tram track and turnout geometry measurement ... · Light rail, tram track and turnout...

Light rail, tram track and turnout geometry measurement and diagnostic tools

J. Madejski GRAW sp. z o .o., Poland Institute of Engineering Materials and Biomaterials, Silesian University of Technology, Poland

Abstract

The paper explains the need to collect and store track and turnout geometry information and how to determine their condition in the form of synthetic quality coefficients. Catenary data feature an example of the additional line information that can supplement the infrastructure information database. The concept of line-speed dependant track parameter tolerance values is presented. Analysis of the temporal trend of the track and switch geometry change calls for measurement data storage and analysis. The relevant database system is described along with the examples of queries. Real life examples and experience with this methodology of track and switch geometry parameter analysis in Poland and other EU countries are presented. The diagnostic module indicates the "weak locations" in the track, which can be further analysed in detail by the diagnostician. Keywords: track geometry, turnout geometry, track infrastructure database, track recording trolley, track diagnostics.

1 Introduction

New projects related to light rail, metro, and trams are ongoing all over the world. The key is to promote the development of attractive alternatives to the use of private cars in cities, reducing congestion and pollution through new technologies, innovative planning measures, enhanced energy efficiency and the use of alternative fuels. These means of transport have zero emissions and – in case of trams are seen to discipline other traffic. The aforementioned projects include developing new lines, rebuilding some tram lines and converting them to

© 2005 WIT Press WIT Transactions on The Built Environment, Vol 77, www.witpress.com, ISSN 1743-3509 (on-line)

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metro, like in Porto (Portugal) where one of the narrow gauge lines is to be re-gauged and converted to metro, as well as expanding the existing tram lines, even in case of very narrow gauge - like in Linz (Austria), which is served by a 900 mm gauge tramway and yet operates modern fleet [1]. An important new feature is the expanding track-sharing. This is an important development of the last decade of through running of light rail vehicles on heavy rail tracks in cities such as Karlsruhe and Saarbrücken (Germany). This enables seamless journeys for commuters serving suburban settlements and penetrating city centres. This new traffic organisation greatly reduces the capital costs of infrastructure as compared with the costs of building totally new lines, yet requires hands on experience from the service providers in both heavy rail and light rail construction and maintenance [2]. The same is required from the diagnostic equipment to be used by these companies which have to maintain much diversified lines – table 1.

Table 1: Light Rail compared to other types of rail transport. Dutch Ministry of Transport and Public Works [3].

Characteristics Tram Light Rail Metro Heavy Rail

Typical vehicle width 2.35 m 2.65 m 3 m 2.80 m

Platform height 0.15 m variable 0.90 m 0.75 m

Dedicated track partially partially completely completely

Min curve radius 18 m 25 m 150 m 250 m

Transfer overhead overhead third rail overhead

Block security system none partially fully fully

Max speed 70 km/h 80-100 km/h 80 km/h 120-160 km/h

Average speed 15-25 km/h 35-70 km/h 30-35 km/h 60-70 km/h

Frequency per hour 4-10 1-12 4-12 2-6

2 Infrastructure documentation

Many European cities have retained their traditional tramway systems dating even from before the Second World War and could neither afford to abandon them nor were willing to consider doing so. In some cases cities have found it desirable and possible to upgrade and develop their traditional tramway systems, into modern networks based of modern light rail/tramway technology and practices [2]. Nowadays, they face problems with documenting their infrastructure, which is the precondition to their proper maintenance and development planning [1, 4, 5]. Therefore track condition assessment rules are needed as well as hardware and software tools to accomplish documenting track condition and carry out its computer assisted diagnostics.


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2.1 Track condition synthetic coefficients and reporting

All software systems presented further herein have been based on the track condition assessment rules directly related to line speed [6-8]. In principle, there are no fixed tolerance limits to which the actual track parameters exceedings would be compared, but the tolerance limits for all directly measured track geometry parameters like gauge, cant, vertical and horizontal irregularities and those calculated like track gauge gradient and twist are used to calculate the dynamical (J) and static (W5) synthetic coefficients [9-11]. To make the track and turnout condition assessment more accurate and follow the condition deterioration while still within tolerance limits, three classes of deviations of parameter value have been specified for each parameter [12, 13]. The A and B class deviations are only counted for statistic purposes. Class C deviations – equal to 100% of the tolerance value for the particular line speed are called track defects and considered as track defects. The 50% value of a class C deviation gives the class A deviation value, while 75% of class C is the class B deviation. This attitude has been accepted and implemented by many tram, metro and light rail companies in Poland (Warsaw Metro, Cracow Trams, to mention but few.), The Netherlands (Rotterdam Trams, Amsterdam Trams, Sunij-Lijn light rail), Belgium (Brussels Trams), Croatia (Zagreb Trams), Hungary (Budapest Metro), and others. Measurement results are generated in two forms: graphical and tabular printouts. The tabular data is printed during the measurement and consist of the following report types:

• detailed reports: listing defects and characteristic points of line, • statistical reports: with totals for all geometrical parameter types, • synthetic reports: with standard deviations of all parameters and the

synthetic assessment of the track condition.

All reports are made for the basic section of track ranging from 100 m to 1000 m. Cumulative reports are available which containing data on a line section or entire line. Plots of all measured track parameters include, apart from the representation of track parameters’ values, also other additional information, like:

• hectometer markers, • track number, class and line speed, • curve markers, • markers of certain objects, like semaphore, bridge or switch • speed value • bar chart indicating occurrences of deviations in classes A, B, C.

2.2 Portable track geometry measurement systems

The track condition assessment methodology adopted by companies mentioned in section 2.1 has been based on the family of TEx trolleys, featuring the microprocessor based devices logging the main track geometry parameters versus the distance covered. They have been developed to meet all measurement needs listed in table 1. The family of the Tex trolleys includes the base TEC


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system [14] with various extensions, all of which are furnished with the relevant PC software. The TEC trolley is used for track and turnout diagnostics, and thanks to its small overall dimensions and compact design it is easy to take the device off the track to let the approaching train pass and then to get back to the track to continue the measurements. Regulations of some railways call turnout geometry control at some particular transverse section and for measurement of the groove width in the turnouts [9, 11, 15]. For such applications special groove measuring elements were added to the TEC trolley and its keyboard functionality was extended, thus a new device was developed - the TEE trolley. The TEC trolley can be also a mobile platform carrying the special tripod with the laser distance meter for measuring the distance of the infrastructure objects from the track axis. Instead of the laser device or in addition to it, one may fix the optical prism on the tripod, for co-operation with Total Station - this device version is called Total-TEC.

Figure 1: Measuring the catenary pole position using Laser-TEC.

2.2.1 Laser-TEC – track outer gauge measurement Ladar add-on mounted on the TEC-1435 trolley makes it possible to measure structures and objects whose sizes exceed ∅ 10 mm, including, among others: light signals, tunnels, platforms, inter-track space, as well as height of the contact wire, poles, and other elements within 7 m from the track axis. Measurements of the clearance gauge elements may be carried out during the track geometry measurements.


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Clearance gauge measurement is carried out after stopping the trolley, when the operator aims the laser beam to the selected point, be it a pole, contact wire, or any other object. The distance from the measured point to the track axis is displayed on the trolley keyboard. Measurement results, along with the object location, are stored in the trolley's electronic memory. Measurement error does not exceed ± 5 mm. The trolley's memory content is transferred to the PC when the measurement session is over. The PC software can print the clearance gauge inventory sheets.

2.2.2 Total-TEC – track position measurement This tool is used when the track geometry has to be linked with the surveying data, i.e., when the exact geographic location of the track is required. This has been achieved by developing a trolley designed for working with the Total Station system. Mounting of the prism is provided with the Total-TEC (see figure 2) in a position in which it can be seen from the Total Station’s lens at all time. The TEC Special keyboard software is extended to assign identification numbers to the generated measurements in the digital format. Its dedicated PC software carries out the following tasks:

• PC software makes it possible to enter the surveyor’s X, Y, and Z corrections for the location of the prism centre in respect to the track axis in the measured section.

• Reading the Total Station measurement data files. • The Total Station measurement data is synchronised with the TEC

measurement data using the identification numbers. • The Total Station measurement data with prism positions is recalculated

into the position of track axis, right and left rail, further the calculated measurements are exported into the GENIO (TXT) format file – compatible with MX-rail system (other formats are also available).

• Z-values may be combined with vertical irregularities. • X and Y-values may be combined with horizontal irregularities. • Versines can be calculated for various track lengths in vertical (lift) and

horizontal planes (shift) • Extended TEC report

o XY-plot is generated taking into account the shift value o XZ-plot is generated taking into account the lift value

2.2.3 TEM-1xxx – third rail position measurement Track measurements taken in metro often require determining the position of the third rail. This can be achieved using the special version of the TEC system -such system has been used since years by Warsaw Metro. The system’s software is based on the standard trolley software version, with one of the track geometry parameters substituted with the third rail data.


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Figure 2: Total-TEC in the track, working with Total Station.

Figure 3: Fragment of the exemplary tram road network model.

Terminal

Track between junctions

Intersection

Track networkmodel separators


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Table 2: Classification of GeoTEC track attribute groups [12].

Attribute group Symbol Description

Continuous C The attribute values may change but have to be specified always.

Attribute name Exemplary values Rail type S49, Ri60, S 42 Sleeper type wooden, concrete Fixture type SB, K Ballast breakstone Track type classical, CWT Track construction year 1980 General overhaul year 1985 Rail build in year 1990 Turnout build in year 1992 Track class 0,1,2,3 Classical track span 210 Rail manufacturer Xxxx Rail processing heat treated Rail joint type welded, glued Platform platform 1

Segmental S Occurring over the particular track sections only. Overpass ID Drainage system type Xxxx

Punctual P Occurring at the particular locations in the track. Signal light ID

Object O Elements that need more detailed description for the diagnostician than only mentioning their location and type.

Turnout RZ UIC60-1200-1:18,5l Signal semaphore, distant signal Catenary pole Xxxx Trackside equipment transformer cabinet, TPE Bridge, viaduct, tunnel steel bridge, stone viaduct Tram stop ID Crossing ID

2.3 GeoTEC

The GeoTEC system has been developed for storing data about the track condition collected using the track recording cars and microprocessor based trolleys. The system consists of two subsystems: database with a model of


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the track network model, and the database with the measurement results. An important feature of this database is its capability of storing the real track geometry measurement results along with its design specification, so comparison of the actual track geometry and the theoretical one is possible. Moreover, it is possible to compare many “historical” readings of the track to detect the rate of its deterioration in terms of particular parameters and/or the track synthetic quality coefficients. A diagnostic analysis requires also referring the obtained assessment results to actual track elements such as a type of rail, type of ballast, objects such as crossings, crossovers, etc. Objects and attributes were divided into the following four groups – table 2.

Track network model assumed, for instance, by Cracow Trams, includes three groups of tracks (see figure 2):

• tram loopways - terminals, • turnout nodes - intersections (track sections in the street junctions – the

node boundary being determined by the external turnouts in the junction),

• internodal sections – track sections between intersections (these track sections reach to the first turnout in the terminal nr node).

Track network definition

Track and turnout geometry measurement results,

other infrastructure data

Other data: e.g., telecommunicationsystem, power supply system, etc.

Presentation layers0

1

2

Figure 4: Structure of the GeoTEC map user interface.

Not all information about the infrastructure information (table 2) has to be entered to the GeoTEC database. This information assists the diagnostician drawing conclusions about the track conditions, yet is auxiliary only to the track network data. An important feature of GeoTEC is the possibility to present the detailed information about the track geometry, with the possibility to access the detailed turnout geometry measurement data and all information about the


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infrastructure that has been stored in the database. This information may include geometry of the catenary system or the third rail. All this information may be processed by an expert system integrated with GeoTEC. Assigning some infrastructure element as an object makes it possible to include it on the map interface using the GIS technology – figure 4. GeoTEC map user interface makes it possible to link the track network model with the surveying data obtained using, e.g., Total-TEC. In this way all track data may be shown directly with the line map in the background. All objects defined in addition to the tracks may be included in the GeoTEC user map interface - figure 5. Track condition data may be reflected by colours applied to the line sections, in addition to the detailed data available in the separate reports.

Figure 5: GeoTEC map interface for Sunij-lijn light rail system [12].

3 Summary

The experience shows that using pure statistics of defects in various classes, instead of making use of the real track data, like exact location of defects, local conditions, substructure type, etc, does not allow the infrastructure maintenance services to evaluate fully the track condition. One more deficiency of this statistics is that it separates different types of defects: twist from cant or vertical irregularities, or track gauge from its horizontal irregularities. The track, however, should be perceived as an entity with its design data and geometry linked together. Synthetic assessment, based on the speed based tolerance limits has proven the system of choice by many tram, metro and light rail operators and maintenance companies - table 3. The knowledge of the synthetic track quality


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coefficients is required to take the economically justified decisions connected with planning of major overhauls of the longer track sections.

Table 3: Allowable deviations of track geometrical parameters depending on line speed [9, 17].

Irregularities Twist Deviations of rail gauge Speed Horizontal Vertical on 5 m Widening Narrowing Gradient Cant J

Km/h mm mm mm mm mm mm mm mm 30 44 40 25 25 9 3 25 12.0 40 35 35 23 20 9 3 25 11.0 … … … … … … … … … 90 15 16 15 10 8 2 18 6.2

References

[1] http://www.civitas-initiative.org/civitas/home.cfm [2] http://www.lrta.org/ [3] Dutch Ministry of Transport and Public Works (1995) (1997) SBO (2000) [4] Oleksiewicz W., “Implementation of the track maintenance decision

support system in Warsaw Trams”, International Scientific and Technical Conference on “Contemporary technical solutions in tram communication”, Wrocław 21.05-2.06.2000, pp.37-45 (in Polish)

[5] Piotrowski A., „Issues of the tram road technical condition assessment criteria”, International Scientific and Technical Conference on “Contemporary technical solutions in tram communication”, Wrocław 21.05-2.06.2000, pp.33-35 (in Polish)

[6] Bogdaniuk B., „Maintenance of tracks using the integrated diagnostics system”, Proceedings of the First Seminar on Diagnostics of Permanent Way, Gdańsk 18-20 May, 1999, Poland, pp.41-66 (in Polish)

[7] Lewiński L., Szczepiński D., “Planning of track maintenance based on the synthetic coefficient value analysis”, Proceedings of the Second Seminar on Diagnostics of Tracks, Gdańsk 24-26 May, 2000, Poland, pp.75-88 (in Polish)

[8] Madejski J., Grabczyk J., “Track and Rolling Stock Quality Assurance Related Tools”, chapter in a book: “Structural Integrity and Passenger Safety” - Wessex Institute of Technology, 1999, pp.85-114

[9] Madejski J., Grabczyk J., “Continuous geometry measurement for diagnostics of tracks and switches”, Delft University of Technology, The Netherlands, International Conference on Switches: Switch to Delft 2002, March 19-22, 2002

[10] Burghardt J., Iwaszkiewicz M., Madejski J., “System for the real time railway track geometry parameters evaluation”, Proceedings of the 7th International Conference on Signal Processing Applications & Technology, Boston, Massachusetts, USA, October 7-10, 1996, vol. 2, pp.1821-1825

[11] Tiecken J., “A switch is a track”, Delft University of Technology, The Netherlands, International Conference on Switches: Switch to Delft 2002, March 19-22, 2002


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[12] Madejski, J., “System approach to track and turnout geometry diagnostics”, 12th International Seminar „Track Maintenance Machines in Theory and Practice SETRAS 2004”, Zilina, Slovak Republic, October 13-14, 2004

[13] Madejski, J., “Track condition diagnostic system”, Plovdiv, October 14-17 2004 at the University in Plovdiv

[14] User Manual for TEC-1435 Track Gauge, GRAW, 2002 [15] User Manual for TEE-1435 Track Gauge, GRAW, 2002 [16] User Manual for TET-1067 Track Gauge, GRAW, 2003 [17] User Manual for GeoTEC Track Diagnostics System, GRAW, 2003

(in Polish)


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Light rail, tram track and turnout geometry measurement ... · Light rail, tram track and turnout...

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