Graeme Templer, Australasian Transport Risk Solutions (ATRS) - A Look at Special Cases of Turnouts

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Graeme Templer, Australasian Transport Risk Solutions (ATRS) delivered the presentation at the RISSB’s 2013 Rail Turnouts Workshop.

The RISSB’s National Rail Turnouts Workshop 2013 gives all those involved an in-depth forum to consolidate and share the latest technical information for rail turnouts. Drawing on industry expertise, the workshop features technical and practical presentations that address key turnout functions in an every-day operational context.

For more information about the event, please visit: http://www.informa.com.au/railturnoutsworkshop13

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Graeme Templer, Australasian Transport Risk Solutions (ATRS) - A Look at Special Cases of Turnouts

  1. 1. A look at special cases of turnouts Graeme Templer Senior Associate, Australasian Transport Risk Solutions (ATRS) May 2013 Newcastle
  2. 2. • Grinding turnouts, when is it necessary? • Effect of wheel profile • Effect of hollow wheels • Rail head shape when not ground • Impacts and discontinuities • Contact band and ARTC grinding standard • Axle load distribution, histogram • Fatigue failure of rail • Heavy haul lessons learned • Rail Seat Tolerances, re inventing the wheel Questioning the Absolute Truths
  3. 3. Grinding turnouts when is it necessary • Impacts
  4. 4. • Frederick’s 1968/74 at a bad fishplated joint, 10 x axle load at rail surface • Australian National Railways 1984/89 3x axle load at dipped peaked or stepped weld • Core 2002 5x axle loads in turnouts • CRC AT9 2010 confirmed the above impacts in turnouts IMPACTS
  5. 5. • The following contact stresses calculated from a computer model • Both wheel and rail profile • Model Moves wheel from side to side to obtain maximum contact stress • Maximum allowable for Pt Kembla rail is 1035 Mpa otherwise corrugations will develop • 985 Mpa to less than 1035 mpa corrugations may develop • Below 985 Mpa corrugations will not develop • (BHP Melbourne research laboratories early 1980’s) Rail stresses static condition no dynamics
  6. 6. New ANZR1 wheel on R3 rail profile Contact stress is 1231 MPa (NCOP profile)
  7. 7. Average worn ANZR on R3 profile contact stress is 1154 MPa
  8. 8. Slightly worn WPR2000 on R3 profile Contact stress 2000 MPa
  9. 9. Average worn WPR2000 on R3 profile Contact stress 1328 MPa
  10. 10. Add Impact factor five times axle load Contact stresses • New ANZR1 on R3 contact stress is 6255 MPa • Average worn ANZR1 on R3 contact stress is 5770 MPa • Slightly worn WPR2000 on R3 profile is 10,000 MPa • Average worn WPR2000 on R3 profile is 6640 MPa • Contact stress for LWC to develop in 47kg,53kg rail ex Pt Kembla is 1035 MPa
  11. 11. Current grinding profile for turnouts 50 40 30 20 10 0 -40 -30 -20 -10 0 10 20 30 40 45 Gauge Corner C/L ~ 30-40 mm Gauge Corner Region Field Side Region Running Surface Region
  12. 12. Joints in T/O’s have not been straightened • Narrow contact band, stresses well above 1035 Mpa • A good strategy to trash the 47kg and 53 kg turnouts is to grind a narrow profile on the rail where weld geometry in turnouts has not been rectified. • Do not grind without rectifying weld geometry
  13. 13. Why does the 47 kg Pt Kembla rail corrugate into 0.5 to 2m wavelength long wave corrugations? • Rail is a poorly designed section for bending • Pt Kembla Rail has a low 0.2% FATIGUE failure yield stress 231 MPa • Fracture mechanics by (BHP) MRL determined that at a contact stress above 1035 MPa corrugations will develop • Speeds and axle loads increased beyond 19 t at 90 KPH • Currently 23 t at 80kph, 21 t at 115kph, locos 23t at 115kph • It is the unsprung mass of the locos that cause the damage • Rail fails in full section bending some plastic flow of the rail surface
  14. 14. Curve 51kms North of Adelaide 19 November, 2009
  15. 15. CAT Trolley
  16. 16. 1m to 1.5m corrugations in rail Derrinallum, Western Line Victoria, 47 kg on Concrete, instantaneous values greater than 0.3mm
  17. 17. Rail GTKs have an influence on residual life of 47kg 53kg rail • Western Victoria 300 MGT • Vic Border to Adelaide 500 MGT • Some sections of TAR 500 MGT • Some sections of the TAR 200 MGT • Coonamia to Broken Hill 150 MGT • Melbourne to Albury 300 MGT • Tottenham to Newport 500 MGT • Victorian NE West track 50 MGT • Southern NSW 53 kg rail 200 to 300 MGT • Northern NSW 200 MGT maximum
  18. 18. Why grind the East West Nth Sth rail? • To prevent corrugations forming • Weld geometry in T/O’s has never been rectified • Axle loads are such that normal surface defects shelling, flaking spalling RCF does not develop. • Grinding does not improve dipped weld geometry • Grinding a narrow contact band increases contact stresses with impact which ensures the corrugations will develop faster • Why grind?
  19. 19. The P1 gauge
  20. 20. MP12 grinders incapable of producing 0mm peak over 1m
  21. 21. Intermodal axle loads
  22. 22. From wayside Approximately 12 % of axles are above 19 t those that do the damage to the rail
  23. 23. Final Grinding: A reciprocating grinder. GOOD FINISH, REGULAR LATERAL PROFILE AND NO DIPS
  24. 24. Another type linear grinder
  25. 25. Good lateral profile as a bi-product
  26. 26. Weld shape effect • Effect of shape of weld profile • Next lot of slides Dipped weld profile not improved by grinding
  27. 27. Weld pulls down with incorrect grinding technique TR Weld 0010G018 217.5 km - Mar 2001 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 -500 -400 -300 -200 -100 0 100 200 300 400 500 Distance from Weld C/L (mm) Height(mm)
  28. 28. Coota to Parkes Weld profile after straightening
  29. 29. Coota to Parkes after straightening
  30. 30. Fatigue curves Stress versus cycles Bending Stress Pt Kembla rail
  31. 31. Summary • If average axle loads are below 20 t. Ask the question why are we grinding the turnouts • If you decide to grind because it is nice to have then rectify the welds first • Grind off welds with a reciprocating linear grinder • Throw out the P1 gauges • Note turnout grinders do not grind pout long wave corrugations in turnouts • Long wave corrugations 0.5m to 2.0m primarily 0.7m
  32. 32. Wheel profile the WPR2000 wheel • Effect of introduction of the WPR2000 wheels to the Interstate Network
  33. 33. The WPR2000, I in 10 conicity with a worn profile in the corner The high conicity is designed to pull the high outer wheel from the high rail and reduce wear of both wheel and rail The thickening of 7mm total in the gauge corner gives the wheel more metal to wear The 1 in 10 conicity allows this profile to go around tighter curves than the ANZR1 profile without wheel creep
  34. 34. Stability for wheels that end up with a lot of running on tangent tracks
  35. 35. Conicity of the WPR2000 Profile 0 20 40 60 80 100 120 140 -30 -20 -10 0 10 20 30 40 50 60 70 WPR2000 wheel profile Millimetres Millimetresorconicity1:n WPR2000 shape Conicity, 1:n
  36. 36. WRP2000 on un canted rail as per all of ARTC unground T/Os except new Vossloh T/O
  37. 37. Contact Band through Points and unground crossings Note at bottom and top through VEE At sides on running rail WRP2000 on Gauge
  38. 38. Vee crossing up end Leeor Loop
  39. 39. Ararat mixed gauge diamond K crossing
  40. 40. Westmere Down End Vee crossing
  41. 41. Tattyoon up end vee crossing
  42. 42. Lubeck up end Vee crossing
  43. 43. Murtoa up end vee crossing
  44. 44. Murtoa down end vee crossing
  45. 45. Jung siding
  46. 46. Pimpinio vee crossing down end
  47. 47. Gerang Gerung down end vee crossing
  48. 48. New vee crossing at Stawell in service for two weeks
  49. 49. New vee crossing at Stawell
  50. 50. New vee crossings at Stawell
  51. 51. Vee crossings at Stawell
  52. 52. T/O at Musswellbrook Note how wheels with high conicity cause abnormal wear
  53. 53. Recent order for turnouts had the same problem • For a third time a new supplier delivered turnouts not designed for the WPR2000 wheel still used in the Hunter Valley • Change of people and drawings not altered • Wheel profiles must be given to supplier
  54. 54. Solution
  55. 55. Hollow wheels • When the WPR2000 profile was introduced no wheel condemning gauge was introduced to measure hollowing • Wheel became more hollowed that prior to the WPR2000 introduction • Effect of hollow wheels Effect of wheel defects
  56. 56. Plastic failure in the gauge corner creating untestable rail Corrugations, Shelling, Flaking, Squats, RCF
  57. 57. Hollow wheels Solution is to grind a champher in the gauge corner What is actually happening • Grinding off the corner creates high contact stresses at the interface pf corner grinding • this leads to accelerated RCF • This generates more grinding to remove the RCF • Solution new wheel gauge developed and hollowing defined fro the WPR2000 wheel
  58. 58. Warp of the rail seats relative to each other • This is a condition not understood in ARTC until relatively recently • However was a common problem in the heavy haul and South Africa • For twenty years there had been a truth it was caused by peak and dipped welds
  59. 59. Mould numbers still visible • Mould numbers are still visible • Sleepers that skew have same mould numbers
  60. 60. Possible mechanism that causes skewing Rail seat Casting tolerances
  61. 61. Skew Sleepers TAR
  62. 62. Skew Sleepers TAR
  63. 63. Special pad to prevent skewing
  64. 64. Mechanism of sleeper skewing • Identified in overseas railway in Pilbera in Australia • Cause is warping of rail seats in longitudinal direction • Moulds tolerance should be 1 in 400 on rail seat but some moulds are 1 in 100 • Demonstrate with eraser
  65. 65. The longer rail span • The longer span over skewed sleepers increases the rail stress even further • Fatigue life of rail is shorter than we think
  66. 66. Bending stress with skewed sleepers • The bending stress with skewed sleepers is 60 % higher than with regular spaced sleepers will have a significant impact on rail fatigue life
  67. 67. Lesson for turnouts • Rail seat tolerances must be 1 in 400 for rail seats in the turnouts • If this cannot be achieved then special anti skew pads should be provided for turnouts
  68. 68. Heavy haul • Some examples in the Hunter Valley • Kinematic Gauge Optimisation • It’s a development from one of the suppliers, twice as expensive as a normal turnout but they last at least 3 times as long • They are shaped with a curve in turnout Points 203 • Hunter has installed 2 x KGO switches, 203a points has lasted 4 years, previous switch life was 12months. • Also on at 142Pts installed Nov 2009, still OK, previous life 6 months
  69. 69. • The tangential switch assembly is an AS60Kg / AS68Kg ZU1-60 arrangement that has been • manufactured to improve performance by incorporating Kinematic Gauge Optimisation or KGO • In simple terms the switch and stock rail have been designed to assist the wheel in traversing the • entry into the switch by controlling the wheel more effectively in both the straight and curving • movements. The KGO design achieves this by bending the stockrails outwards by up to 15mm to • achieve a varying rolling radius difference on the wheel. This widening of the stockrail at the entry • of the switch also has the added advantage of increasing the thickness of the blade through the first • 10 metres of the blade
  70. 70. Points 203 in the Hunter
  71. 71. Swing Nose Frog
  72. 72. Flushing Questions Money

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