MTST RAIL GRINDING

Transcription

1 Engineering Standard Track MTST Version: 2 Issued: February 2015 Approved By: Paul O Halloran Chief Engineer PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION

2 Approval Amendment Record Approval Date Version Description 22/11/ Initial issue under MTM. Universal profile (MTM profile) for milling added. Document renumbered from L2-TRK-STD-001 with modifications in section 2.0 Scope and added section 8.0 Rail Milling. 03/02/ In section 10.2 Template Fabrication, amended the template fabrication tolerance from +/- 0.1mm to +/-0.025mm. Appendix 4 added. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 2 of 37

3 Table of Contents 1. Purpose Scope Abbreviations Definitions References & Legislations Responsibilities Safety and Environmental Rail Milling Rail Grinding Types of Rail Grinding Corrective or Defect Grinding Transitional Grinding Preventive or Cyclic Grinding Special Grinding Rail Profiles Templates Template Fabrication Calibration Template Application Placement Tolerance to Template Allowance for Rail Rotation Allowance for Transposed Rail Gauge Corner Relief Field Side Relief Metal Removal for Grinding Metal Removal for Corrective Grinding Metal Removal for Preventive/Transitional Grinding Plain Track Turnouts Surface Finish Grinding Facets Other Surface Irregularities Competencies Related Documents Records Appendices Appendix 1 Tangent Rail Template and Contact Region PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 3 of 37

4 16.2 Appendix 2 High Rail Templates and Contact Region Appendix 3 Low Rail Templates and Contact Region Appendix 4 Template Co-ordinates for Universal Profile (MTM Profile) of Rails in Tangent and Curves List of Tables Table 1: X-Y Co-ordinates of Tangent (TGT) Template Table 2: X-Y Co-ordinates of High Rail (H1) Template Table 3: X-Y Co-ordinates of High Rail (H2) Template Table 4: X-Y Co-ordinates of Low Rail (L1) Template Table 5: X-Y Co-ordinates of Universal (MTM) Rail Template List of Figures Figure 1: Contact Band (indicated by arrow)... 6 Figure 2: Directions in Rail... 7 Figure 3: Flaking Defect on Rail Head... 7 Figure 4: Regions in Rail... 8 Figure 5: Gauge Corner Cracking... 9 Figure 6 - Typical arrangement of a milling cutter head for rail milling Figure 7: Short Pitch Corrugations in Rail Figure 8: Shelling in the Gauge Corner of Rail Figure 9: Components of a Turnout Figure 10: Example of Metal Removal Requirements in Worn Rails in Tangent Track Using the TGT Template Figure 11: Example of Metal Removal Requirements in Worn High Rails in Curved Track Using the H2 Template Figure 12: Example of Metal Removal Requirements in Worn Low Legs in Curved Track Using the L1 Template Figure 13: Example of Metal Removal Requirements in Worn High Rails with Severe Corrugations in Curved Track Using the H2 Template Figure 14: H1 and H2 High Leg Grinding Profiles Figure 15: Example of Holding Bar for Template Figure 16: Unacceptable Gauge Corner Undercutting (Arrow Points to Gauge Corner) Figure 17: Gauge Corner Checking Defects Left in the Rails after Grinding (Arrow Points to the Gauge Corner) Figure 18: New 60kg/m Rail in Turnout with Tangent (TGT) Template Figure 19: Acceptable Standard of Finish from Grinding Figure 20: Unacceptable Severe Grinding Scratches (Arrow Points to Gauge Corner) Figure 21: Unacceptable Cyclic Grinding Scratches Figure 22: Tangent (TGT) Template and Nominal Running Surface Contact Figure 23: High Rail (H1 and H2) Templates and Nominal Running Surface Contact Figure 24: Low Rail (L1) Templates and Nominal Running Surface Contact Figure 25: MTM Rail Template PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 4 of 37

5 1. Purpose The primary objective of this document is to define the maintenance standards for the grinding of running rails with the express purpose of increasing the life of track and structures assets as well as rolling stock assets. This document describes the Rail Grinding requirements for the Melbourne Metropolitan Rail Network, contained within the Infrastructure Lease managed by MTM. Rail Grinding will increase the life of both track and rolling stock assets by optimising the wheel/rail interface. Importantly, the document also establishes rail profiles that shall be used on track within the Melbourne Metropolitan Rail Network and the quality of grinding to be achieved. NOTE: This Standard has, in part, been compiled from various industry standards considered by MTM Engineering to be best practice in the development of standards, criteria and requirements for rail grinding to be applied within MTM. 2. Scope This document provides details of the background and implementation processes associated with Rail Grinding, and include: Common definitions applied in Rail Grinding Types of Rail Grinding Rail Profiles and associated Templates and Tolerances Metal Removal for Grinding Surface Finish Requirements NOTE: The requirements specified by this Standard shall be applicable to alternative methods of achieving desired rail profiles e.g. Rail Milling. A potential universal rail profile (identified as the MTM profile) has been developed for milling, which basically combines the characteristics of the current H2 high rail template towards the gauge side, and the current Tangent template towards the field side. Refer to Appendix 4 and section Abbreviations H1 High leg profile for curves with radius less than 800m H2 Transitional high leg profile for curves with radius less than 800m L1 Low leg profile for curves with radius less than 800m L eq MGT MTM Sound exposure level expressed in decibels (dbs) Million Gross Tonnes Metro Trains Melbourne Pty Ltd R a Average Roughness as per AS 2382 TGT Tangent profile, for tangent track and curves greater than 800m PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 5 of 37

6 4. Definitions Authorised MTM Representative Checking Locations Contact Band The Infrastructure Delivery Manager or his delegated representative. Specific points marked on the rail where the achievement of the defined rail profile and / or metal removal is checked and monitored. The contact position of the wheels on the rail as evidenced by the shiny worn surface as shown in Figure 1. This generally applies to wheel contact occurring on the running surface region of the rail. Corrective or Defect Grinding Digital Rail Profile Measuring Device Figure 1: Contact Band (indicated by arrow) Grinding carried out to remove specific defects in the rail. Such defects may occur over a long track section (rail corrugations or extensive rolling contact fatigue) or over short track sections (wheel burns or isolated rolling contact fatigue defects). An electronic device used to measure and check the profile of the rail with the information being collected and stored for later analysis. These can be both automated running inline with a vehicle or manual handheld types. Generally, the manual version is placed on top of the rail and via either a inbuilt laser or tracing wheel, the actual profile is measured providing an overall outlay to be compared against predefined rail templates. Within the rail industry there are a variety of versions available depending on the operator requirements but in affect complete the same function. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 6 of 37

7 Directions in Rail Figure 2: Directions in Rail Flaking Flaking is a surface condition that propagates from the shear stresses applied to the rail head at the wheel contact areas of the low leg. It appears as a mosaic or snakeskin like pattern on the rail head. In the latter stages of growth these cracks begin to 'spall', mainly in the centre of the rail head, and can be continuous over the rail length (refer to Figure 3). Figure 3: Flaking Defect on Rail Head Field Side The side of the rail opposite the gauge face (refer to Figure 4) PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 7 of 37

8 50 Field Side Region Running Surface Region 40 mm Gauge Corner Region 40 Outside of 30 Track C/L Gauge Corner 4545 Inside of Track Field Side Relief Gauge Bar Figure 4: Regions in Rail Clearance between the wheel profile and the rail profile to reduce wheel / rail contact on the head of the rail in the field side region. A rod or bar section which sits between and normal to the rails to provide a superelevated reference for the application of the template. Gauge Corner The top corner of the rail above the gauge face (refer to Figure 4) Gauge Corner Relief Clearance between the wheel profile and the rail profile to reduce wheel / rail contact on the head of the rail in the gauge corner region. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 8 of 37

9 Gauge Corner Cracking or Head Checks A surface condition that propagates from the shear stresses applied to the gauge corner contact region of the high rail in curves. It results in the deformation of the rail surface, and could be described as being like fish scales. The head checks generally occur at about 2-5 mm intervals and can grow to the same depth, gradually spreading across the rail head. Once this occurs they can break out as spalls. If left in track, head checking will deteriorate further into a shelling flaw, and in turn, possibly a transverse defect (refer to Figure 5). Gauge Face Grinding Operator Grinding Facet Hi Leg Lipping Low Leg Rail Milling Figure 5: Gauge Corner Cracking The zone of the rail head facing the inside of the track. In the tighter curves the gauge face may be worn due to contact with the wheel flange. The party conducting rail maintenance / grinding activities on behalf of MTM. Flat ridges left on surface of the rail by grinding stones after grinding passes. The high rail in canted track. Overhanging metal due to plastic flow (rail flow) of the steel rail. The low rail in canted track. A process that removes material away from a given area on the rail head to a pre-defined profile by the use of rotating cutting heads. Unlike conventional rail grinding, which consist of an array of grinding wheel each removing a set amount, a standard rail milling operation consists only of one set of milling cutters and a pair of grinding wheels used to clean up the machining marks. There is also the by-product of metal swarf (filings) which is collected inline by the machine. In essence either rail grinding or milling operations can be used to re-profile the rail. Typical rail milling cutter is shown in Figure 6. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 9 of 37

10 Preventive or Cyclic Grinding Profile Grinding Rail Corrugation Figure 6 - Typical arrangement of a milling cutter head for rail milling Grinding carried out to a regular schedule for the purpose of maintaining the rail profiles, preventing or inhibiting the growth of defects, and maintaining the surface condition of the rail (particularly in terms of corrugations and local vertical irregularities), with a minimum metal removal of mm from the rail contact surface each grinding cycle. Grinding carried out to create the desired rail profile which provides the correct contact band on the rail surface and wheel/rail interface. Best practice indicates that profile grinding may occur across the network. This may be based upon MGT and Rail condition as part of the agreed to Asset Management Strategy. Cyclic (wave-like), generally vertical, irregularities on the running surface of the rails. Corrugations form from either the differential wear caused by a repetitious sliding action of the wheel on the rail, whether through acceleration, braking or lateral motion across the rail, or from plastic flow of the rail material due to excessive contact stresses and the combined resonance of the wheel set unsprung mass and the track. Corrugations are generally 0.1mm to 0.5 mm in depth, although sometimes can be larger, and may be: Short pitch - from about 30 mm to 90 mm in wavelength, which are associated with the lighter axle load passenger traffic (refer to Figure 7); PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 10 of 37

11 Rail Flow Rail Grinding Template Rolling Contact Fatigue (RCF) Running Surface Records Shall Shelling Figure 7: Short Pitch Corrugations in Rail Long pitch - from about 200 mm to 450 mm in wavelength or more, this is typically associated with heavier axle load freight traffic. Plastic flow of the rail surface material, which may occur on high, low and tangent rails, both on the field and gauge sides. It results from exceeding the yield strength of the material, which can occur because of various reasons including higher tractive effort and poor matching of wheel and rail profiles (including wheel hollows). A template used to fit over the head of ground rail to show the relationship of the ground rail to the defined rail profile. This is a generic term used to describe a range of defects which are due to excessive wheel / rail contact stresses and which may be of the following types: Gauge Corner Cracking / Head Checks Flaking Shelling The zone on top of the rail head which makes contact with the wheel tread (refer to Figure 4). Objective evidence of having satisfied this Standard through measurement, calibration, certification and inspections. Is used as the descriptive word to express a requirement that is mandatory to achieve conformance to the Standard. An internal defect (approximately 2 mm to 8 mm below the gauge corner), that normally initiates at oxide inclusions or 'stringers' of such inclusions that may be present in the rail steel. It is typically confined to the gauge corner radii of rails on the high side of curves (refer to Figure 8). Shelling cracks form on a horizontal or longitudinal plane consistent with the profile of the rail on the gauge corners. The cracks can continue to grow on that plane, and then either spall out into a shell or turn down and form transverse defects which can continue to grow on a transverse plane and in time will lead to rail failure if not detected. The longitudinal separation from which these transverse defects propagate is not always visible. The presence of lubricants (water and grease) can enhance the growth of shells, particularly in the presence of head checking. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 11 of 37

12 Should Squats Transitional Grinding Tread/Wheel Hollowing Turnout Figure 8: Shelling in the Gauge Corner of Rail Is used as the descriptive word to express a requirement that is recommended in order to achieve compliance to the Standard. Should can also be used if a requirement is a design goal but not a mandatory requirement. Starts as a subsurface tear caused by either rolling stock applying tractive forces to the rail or lateral creep forces. Squats first appear as a dark shadowy area within the running surface. Surface cracking appears over time and surface metal can break out. Grinding carried out over several cycles to transfer from a corrective to a preventive grinding regime. A condition where there is a worn hollow in the wheel treads. Generally tread/wheel hollowing is not observed in passenger rolling stock. A track feature allowing trains to change running lines. A typical turnout is shown in Figure 9. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 12 of 37

13 Points Closure Rail Guard Rail Nose Stock Rail Vee Wing Rail Wheel Burns Figure 9: Components of a Turnout Crossing - Made up of the wing rails, the vee, nose and part of the closure rails. Wing Rail - Non-running rail. Extension of the closure rail past the crossing to guide bogie wheels (Refer to Figure 9). Closure Rail - The running rail in a turnout between the points and the crossing (Refer to Figure 9). Points - Moving running rail section of a turnout (Refer to Figure 9). Vee - Section of crossing where two opposing running rails intersect (Refer to Figure 9). Nose - The apex of the vee. Guard Rail - Non-running rail. Guides bogies wheels through crossing for through running trains (Refer to Figure 9). Stock Rail - Outer running rails, runs continuous throughout the turnout (Refer to Figure 9), referred to as the Straight and Set (curved) stock rails. Structural discontinuities that occur on the running surface of both rails (directly opposite) and are due to the localised slip of a wheel set. This can cause either severe localised deformation or overheating and the transformation of the rail material into a hard and brittle martensitic microstructure. The contamination of the running surface of the rails, by for example lubricants, greatly enhances the development of wheel burns. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 13 of 37

14 5. References & Legislations L0-SQE-MAN-002 L0-SQE-PRO-014 AS AS Safety Management System Manual Safety and Environmental Requirements for Contractors Working On MTM Premises Acoustics - Methods for the measurement of rail bound vehicle noise Surface Roughness Comparison Book of Rules and Operating Procedures Responsibilities General responsibilities for the application of this Standard are set out in the MTM Management System Manual and the relevant personnel position descriptions. All personnel who are assigned a task related to this Standard shall be trained, suitably qualified and competent to carry out that task. 7. Safety and Environmental The general requirements in relation to safety are included in MTM s Safety Management System Manual (L0-SQE-MAN-002). At all times, track inspections shall be carried out in accordance with the current Book of Rules & Operating Procedures 1994, and all relevant Track and Safe working circulars. L0-SQE-PRO-014 Safety and Environmental Requirements for Contractors Working on MTM Premises outline the requirements of contractors operating within MTM s premises. 8. Rail Milling Rail milling is a new process available to the Australian Rail Industry for the removal and rectification of rail defects. The milling process removes defects by cutting out the defects. Refer to Fig 6. for details. The metal waste known as swarf (fillings) shall be collected inline and stored on the milling machine for disposal. The milling process application shall provide; Removal of surface defects with a processing depth of mm, in one pass and includes the treatment of the entire rail head surface profile. Environmentally friendly: no emissions, no dust, no dirt and low noise. High accuracy of traverse and longitudinal profile. No thermal damage to the rail head. Milling process does not produce sparks eliminating the risk of track fires. The process does not require cutting fluid that may cause environmental damage. No need to remove track lubricators as the milling machine runs within the allowable rollingstock outline for MTM trains. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 14 of 37

15 9. Rail Grinding 9.1 Types of Rail Grinding There are four principle types of rail grinding as follows; Corrective or Defect Grinding Corrective grinding primarily aims to remove the rail defects that have developed (including corrugations, gross plastic flow and rolling contact fatigue defects). This entails aggressive grinding procedures that aim to remove a considerable amount of metal (at least 0.5 mm and up to 6 mm) at long intervals that are generally determined by the severity of the defects. Transitional Grinding Transitional Grinding is less intensive than corrective grinding but more intensive than preventive or cyclic grinding. It aims to provide a partial corrective grind in preparing the rail for an eventual preventive or cyclic grind; this is usually carried out over several cycles. Preventive or Cyclic Grinding Preventive grinding primarily aims to eliminate or at least control rail defects and maintain the surface condition and the preferred rail profiles. This entails the removal of small amounts of metal (minimum 0.2mm) at more frequent and controlled intervals. Special Grinding Special Grinding entails the application of grinding in order to achieve specific objectives that usually lie outside the scope of the aforementioned three grinding types, e.g. establishing rail profiles to reduce the rate of wheel hollowing or to provide a very smooth rail contact surface in order to reduce noise generated at the wheel/rail contact. 10. Rail Profiles 10.1 Templates The rail profiles have been specifically developed by MTM to suit the wheel profiles and the rolling stock using the Melbourne Metropolitan Rail Network. As part of the design profiles, the contact band widths and location positions are determined (Refer to Appendix 1-3). The designed rail profiles have been converted into matching templates for use with the rail grinding operation. The rail profiles also address particular problems that have occurred (e.g. rail defects, asset life extension), and form part of a transitional grinding strategy. The details of the template designs are given in Appendix 1, 2 & 3, and their application shall be as follows: Tangent (TGT) Applied to all rails in curves with radii equal to or greater than 800m and is also the nominated profile for turnouts. Refer to Appendix 1 PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 15 of 37

16 High Rail (H1) Applied to the high leg in curves with radii less than 800m. Refer to Appendix 2 High Rail (H2) Applied to the high leg in curves with radii less than 800m, as part of the transitional grinding strategy. Refer to Appendix 2 Low Rail (L1) Applied to the low leg in curves with radii less than 800m. Refer to Appendix 3 It should be noted that in initial Profile Grinding, the High Rail (H2) profile shall be applied to the high leg in curves. Figure 10, Figure 11, Figure 12 and Figure 13 provide examples of the modified profiles in relation to actual worn rails. NOTE: In Figures 10-13, the Field Side and Gauge Side are located on the right hand side and left hand side of the figures respectively. Figure 14 illustrates the difference between the H1 and H2 profiles. It can be seen that the H2 profile leads to a greater amount of metal removal in the gauge corner region. This is required to control the gauge corner checking defects that are currently present on the high rails. It shall be the responsibility of the Grinding Operator to assess the metal removal and hence the grinding requirements. Several guidelines have been provided in Section 11. Also described in Section 11, in certain track sections, there will be a requirement to remove a considerable amount of metal primarily from the running surface of the rails, to control rail corrugations. In all of these cases, the grinding shall be completed by the implementation of the appropriate rail profile, which shall conform with all of the standards applied to the normal preventive grinding practice. It shall be noted that the measurement of metal removal, profiles and tolerances during / after grinding shall be conducted by the Grinding Operator using either a non-contact profile measuring system or a Digital Rail Profile Measuring Device. However, mechanical templates (as per Section 10.4) may be used during the grinding as a means of checking that the design profiles are achieved. Figure 10: Example of Metal Removal Requirements in Worn Rails in Tangent Track Using the TGT Template PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 16 of 37

17 Figure 11: Example of Metal Removal Requirements in Worn High Rails in Curved Track Using the H2 Template Figure 12: Example of Metal Removal Requirements in Worn Low Legs in Curved Track Using the L1 Template PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 17 of 37

18 Y Axis Coordinates (mm) TRACK ENGINEERING STANDARD Figure 13: Example of Metal Removal Requirements in Worn High Rails with Severe Corrugations in Curved Track Using the H2 Template 2 H Field Side Gauge Side -2 H2-4 MTM H1 MTM H X Axis Coordinates (mm) Figure 14: H1 and H2 High Leg Grinding Profiles PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 18 of 37

19 Template Fabrication When mechanical rail templates are used, the templates shall be constructed of hardened steel (or a product of equivalent or superior strength, wear resistance, dimensional stability and durability) to a tolerance of 0.025mm at the profile surfaces. Tolerances at the fixing points for connection to the gauge bar shall be adequate to ensure that overall superelevated profile tolerances (as detailed in below paragraph) are not compromised. The template name, date of manufacture and designed contact band details shall be permanently scribed on the face of the template. The template shall be manufactured with the 1 in 20 (2.86) rail cant included, noting that the co-ordinates for the various templates given in Appendix 1 are for vertical rails and do not include the allowance for rail cant. A gauge bar shall be used with the rail template. The gauge bar provides fixing holes which shall match those on the template. The gauge bar shall provide a reference to the other rail to give a super-elevated reference plane for the application of the template to within 0.2 degrees (i.e. a deviation of less than 2.6 mm from a 1.5m straight edge). The gauge bar shall be made of mild steel, aluminium or other product of equivalent or superior strength, dimensional stability and durability. The gauge bar shall be insulated so that there is no electrical contact between the rails during its application. Figure 15 illustrates an example of a gauge bar to hold the profile template and applied for quality control purposes during rail grinding. Calibration Template calibration shall be checked at initial fabrication and thence six-monthly. The template shall be within 0.05 mm at manufacture and thence within 0.1 mm of the designed profile. Calibration should be carried out with the template fitted to the gauge bar or with a suitably designed calibration block that will allow the proper alignment and matching of the template and the calibration block. If a calibration block is used it shall be within 0.05 mm of the design geometry. To ensure that the gauge bar has not been deformed, it shall also be checked against a straight edge at monthly intervals. The gauge bar needs to be within the original specification of 0.2 degrees (i.e. a deviation of less than 2.6 mm from a 1.5m straight edge). Any other equipment (including the vehicle mounted non-contact system), used for the application of or verification of templates, must meet equivalent calibration and repeatability requirements. Template Application Placement The rail template shall be affixed to the gauge bar. With the non-template end of the gauge bar resting on the other rail, the template shall be placed onto the rail to be checked and moved down and across to maximise the contact of the template on to the rail. NOTE: It is important that no excessive force be placed by the operator on the template or gauge bar, which may lead to their distortion or accelerated wear. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 19 of 37

20 Figure 15: Example of Holding Bar for Template PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 20 of 37

21 Tolerance to Template Plain Track The rail shall be ground so that the profile matches the template. Tolerance shall be checked by measuring the visible gap between the rail and the template using a feeler gauge no wider than 4 mm at the end. The maximum allowable gaps between rail profile and template shall be as follows: For high legs in curves with radii < 800m 0.20 mm within the nominal contact band as shown in Appendix 1 (i.e. a 0.25 mm feeler gauge must not pass between the template and the ground rail head covered by the template).\ For high legs on curves with radii 800m mm in the gauge corner region of the high rails (i.e. a 0.40 mm feeler gauge must not pass between the template and the ground rail head covered by the template) For tangent and low legs mm within the nominal contact bands on, as well as 0.35 mm outside of the nominal contact bands To provide appropriate referencing for the above measurements, the rail templates should contain scribe marks indicating the position of the nominal contact bands as shown in Appendix 1. Turnouts Rail template tolerance requirements for turnouts are as per Section with the following exceptions; All rail flow on the gauge side of rails shall be removed Allowance for Rail Rotation An allowance for potential rail rotation which may be due to rail seat wear and/or applied wheel loads has not been made. Allowance for Transposed Rail MTM do not transpose rail, as such, an allowance for transposed rail has not been made. Gauge Corner Relief Generally any required gauge corner relief is built into the templates. Consequently, gauge corner undercutting, that leads to two point wheel / rail contact conditions in the sharper curves (with radii less than 800 m), as illustrated in Figure 16, and which exceeds the specified tolerances in this region shall not be accepted. Figure 16 also shows that the grinding facet produced at the gauge is greater than the maximum allowable limit of 4 mm (refer to Section 12.1). However, in special circumstances where approved by an Authorised MTM Representative, the rail condition may warrant the use of an additional gauge corner relief, to extend the rail life. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 21 of 37

22 The usage of up to 0.6 mm gauge corner relief as measured by the gap between rail and template may be approved in these circumstances. The grinding facet limits as specified in Section 12.1 must still be observed. Figure 16: Unacceptable Gauge Corner Undercutting (Arrow Points to Gauge Corner) Field Side Relief Generally any required field side relief is built into the templates. Additional relief requirements may be specified but only up to the tolerances stipulated (refer to Section ). 11. Metal Removal for Grinding 11.1 Metal Removal for Corrective Grinding Allowance may be made for some gauge corner cracking/checking to remain after grinding (refer to Figure 17). To minimise the amount of metal removal, major rail rectification (e.g. repair and build up of the nose at crossings), should be undertaken prior to rail grinding works. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 22 of 37

23 Figure 17: Gauge Corner Checking Defects Left in the Rails after Grinding (Arrow Points to the Gauge Corner) 11.2 Metal Removal for Preventive/Transitional Grinding Plain Track When rail (including new rail) is ground under the preventive grinding regime a minimum amount of metal shall be removed. In conjunction with restoration of the rail profile to the designed template as specified in Section 10.1, a minimum of 0.2 mm of metal shall be removed from all surfaces where there is wheel contact, the exception being the gauge face of the high rails (at an angle >45º to the horizontal) in the sharper curves where gauge face wear has been occurring. Turnouts Figure 18 provides an illustration of the tangent profile (TGT) in relation to a new 60 kg rail. Considerable amount of material needs to be removed particularly from the gauge corner region of the new rails. Rails in turnouts are not canted, as with Plain track rails, and hence do not match the wheel profiles. For new rails, grinding shall not extend beyond 10mm on the field side of the rail centre line, as illustrated in Figure 18. The TGT profile exhibits an undercut in the gauge corner region, to ensure that wheel / rail contact is made near the centre of the running surface, rather than the gauge corner region, of the turnout rails. Excessive grinding of the stock rail towards the tip of the switch shall be avoided. This can occur due to the double grinding the stock rails, with the switch both closed and open. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 23 of 37

24 TGT Template Field Side 10mm max Gauge Side Figure 18: New 60kg/m Rail in Turnout with Tangent (TGT) Template 12. Surface Finish Grinding Facets The grinding process leaves visible facets on the head of the rail and gauge face. These facets shall be controlled if excessive contact stress points shall be avoided. The allowable maximum facet width shall be: 4 mm in the gauge corner region 8 mm elsewhere on the ground surface Other Surface Irregularities There shall be a minimum standard of finish arising from the normal rail grinding process, an example is shown in Figure 19. Surface defects identified prior to grinding (such as dipped welds or wheel burns) may not be able to be dealt with as part of the normal grinding operation. Such locations should be noted for separate dealing. Otherwise the requirements are as follows, in terms of possible grinding machine induced characteristics: There should be no sharp ridges especially at the interface of facets There should be no gouging on the rail surface and sharp scratches, as illustrated in Figure 20 There should be no indentations or longitudinal anomalies in the rail There should be no overheating (bluing) of the rail surface There should be no severe cyclic grinding scratch marks, as illustrated in Figure 21. Such scratch marks have the potential to develop into short pitch corrugations PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 24 of 37

25 Figure 19: Acceptable Standard of Finish from Grinding Figure 20: Unacceptable Severe Grinding Scratches (Arrow Points to Gauge Corner) PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 25 of 37

26 Figure 21: Unacceptable Cyclic Grinding Scratches Short pitch corrugations (30-90 mm in wavelength) shall be removed completely, and the remaining longitudinal unevenness along the rail running surface shall be less than 0.05 mm when measured at the centre of the running surface over any 500mm length, using a suitable measuring system. Generally, the assessment of corrugations shall be conducted at the checking location. However, additional measurements may be conducted at any location within a ground section in which visual examination may indicate the presence of cyclic irregularities after grinding In the first grinding cycles, the longer pitch corrugations (about mm in wavelength) shall be reduced In subsequent grinding cycles the longer pitch corrugations shall also be removed, unless otherwise directed by an Authorised MTM Representative, so that the remaining longitudinal unevenness along the rail running surface shall be less than 0.1 mm over a 1m wavelength The roughness over the running surface of the rails shall be no rougher than a R a of 10.0µm, when measured over a distance of 25mm Note: Any measurements of surface roughness (as measured along the rail) need to adopt established and calibrated procedures as specified in AS 2382 Surface Roughness Comparison. There shall be no increase in the maximum level of wheel-rail noise ( 5%), measured using the procedures detailed in AS 2377 (2002), arising from the rail grinding operation (measured after 1-2 MGT of traffic). In this context, noise refers to either sound pressure levels or L eq levels taken at a minimum distance of 10 m from the track, at one (1) second intervals and averaged during the passage of traffic. 13. Competencies N/A PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 26 of 37

27 14. Related Documents MTPR MTPR Internal Rail Defects- Definition and Remedial Action Surface Rail Defects- Definition and Remedial Action 15. Records N/A 16. Appendices Appendix 1 - Tangent Rail Template and Contact Region Appendix 2 - High Rail Templates and Contact Region Appendix 3 - Low Rail Template and Contact Region Appendix 4 - New MTM Template in tangent Track and Curves PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 27 of 37

28 16.1 Appendix 1 Tangent Rail Template and Contact Region Table 1: X-Y Co-ordinates of Tangent (TGT) Template X Y X Y X Y X Y PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 28 of 37

29 Y axis Coordinates (mm) Y Axis Coordinates TRACK ENGINEERING STANDARD X Y X Y X Y X Y Note: The TGT profile has been specified for a free standing rail centreline using the above coordinate system incorporating the rail centreline. Therefore when producing rail profile templates a cant adjustment of 1:20 (2.86) clockwise rotation shall be added so that the profile is referenced perpendicular to the track plane. Rail Centreline Contact Band Not to Scale Rail Contact X -9 X Axis Coordinates (mm) Figure 22: Tangent (TGT) Template and Nominal Running Surface Contact PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 29 of 37

30 16.2 Appendix 2 High Rail Templates and Contact Region Table 2: X-Y Co-ordinates of High Rail (H1) Template X Y X Y X Y X Y PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 30 of 37

31 X Y X Y X Y X Y PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 31 of 37

32 Table 3: X-Y Co-ordinates of High Rail (H2) Template X Y X Y X Y X Y PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 32 of 37

33 Y Axis Coordinates (mm) (mm) TRACK ENGINEERING STANDARD X Y X Y X Y X Y Note: The H1 and H2 profile has been specified for a free standing rail centreline using the above coordinate system incorporating the rail centreline. Therefore when producing rail profile templates a cant adjustment of 1:20 (2.86) clockwise rotation shall be added so that the profile is referenced perpendicular to the track plane. Contact Band H H MTM H1 MTM H Not to Scale X X Axis Coordinates (mm) (mm) Figure 23: High Rail (H1 and H2) Templates and Nominal Running Surface Contact PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 33 of 37

34 16.3 Appendix 3 Low Rail Templates and Contact Region Table 4: X-Y Co-ordinates of Low Rail (L1) Template X Y X Y X Y X Y X Y PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 34 of 37

35 Y Axis Coordinates (mm) TRACK ENGINEERING STANDARD X Y X Y X Y X Y X Y Note: The L1 profile has been specified for a free standing rail centreline using the above coordinate system incorporating the rail centreline. Therefore when producing rail profile templates a cant adjustment of 1:20 (2.86) clockwise rotation shall be added so that the profile is referenced perpendicular to the track plane. Contact Rail Centreline Contact Band Not to Scale -8 Rail Contact X -9 Run-Off X Axis Coordinates (mm) Figure 24: Low Rail (L1) Templates and Nominal Running Surface Contact PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 35 of 37

36 16.4 Appendix 4 Template Co-ordinates for Universal Profile (MTM Profile) of Rails in Tangent and Curves Table 5: X-Y Co-ordinates of Universal (MTM) Rail Template X Y X Y X Y X Y Note: The MTM profile has been specified for a free standing rail centreline using the above coordinate system incorporating the rail centreline. Therefore when producing rail profile templates a cant adjustment of 1:20 (2.86) clockwise rotation must be added so that the profile is referenced perpendicular to the track plane. PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 36 of 37