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Railway engineering


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A brief introduction to Railway Engineering and General Practices Involved

Published in: Engineering
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Railway engineering

  1. 1. Railway Engineering Submitted by: Akshay Kaushal (110134) Jaspreet Singh (110138)
  2. 2. History of Indian Railway
  3. 3. Railway Engineering • It is a branch of civil engineering concerned with the design, construction, maintenance, and operation of railways. • Railway engineering includes elements of civil, mechanical, industrial, and electrical engineering. • Railway engineers handle the design, construction, and operation of railroads and mass transit systems that use a fixed guideway (such as light rail or even monorails). • Typical tasks would include determining horizontal and vertical alignment design, station location and design, construction cost estimating, and establishment of signaling & controlling system. • Railroad engineers can also move into the specialized field of train dispatching which focuses on train movement control.
  4. 4. Section of Permanent Way
  5. 5. RAIL GAUGE The gauge of a railway track is defined as the clear minimum perpendicular distance between the inner faces of the two rails.
  6. 6. Dimension of gauges 1. Broad Gauge(BG) 1676mm(5’6”) 2. Standard Gauge(SG) 1435mm 3. Metre Gauge(MG) 1000mm 4. Narrow Gauge(NG) 762mm(2’6”) 5. Light Gauge 610mm
  7. 7. Coning of Wheels • Coning of wheels – The distance between the inside edges of wheel flanges is generally kept less than the gauge. Gap is about 38 mm on Either side. Normally the tyre is absolutely ahead centre on the head of the rail, as the wheel is coned to keep it in this central position automatically. These wheel are coned at a slope • Theory of coning:- On a level track, as soon as the axle moves towards one rail, the diameter of the wheel tread over the rail increases, while It decreases over the other rail. This prevents to further movement And axle retreats back to its original position (with equal dia or both rails and equal pressure on both rails).
  8. 8. Coning of Wheel on Level-track
  9. 9. RAILS The high carbon rolled steel sections, which are laid end-to-end, in two parallel lines over sleepers to provide continuous and leveled surface for the trains to move and for carrying axle loads of the rolling stock are called rails. `
  10. 10. Functions of the rails: To provide continuous and level surface for the movement of trains with minimum friction with steel wheels of the rolling stock; Provide strength, durability and lateral guidance to the track; Transmit the axle loads to sleepers which transfer the same load to the underlying ballast and formation; Bear the stresses developed due to heavy vertical loads, breaking forces and temperature variance.
  11. 11. RAILS Types of rails: 1. Double Headed Rails (DH Rails) 2. Bull Headed Rails (BH Rails) 3. Flat-footed Rails (FF Rails)
  12. 12. Length of Rails On Indian Railways the standard lengths are the following: Length = 12.80 m. (42 ft.) for BG (say 13 m) and Length = 11.89 m. (39 ft.) for MG (say 12 m)
  13. 13. Corrugated or Roaring Rails In certain places, head of rails are found to be corrugated rather than smooth and straight, when the vehicles pass over such rails, a roaring sound is created which is intense enough to be unpleasant.
  14. 14. Hogged Rails Due to battering action of wheels over the end of the rails, the rails get bent down and get deflected at the ends. These rails are called hogged rails. Measures taken to rectify the hogged rails are: 1. Cropping 2. Replacing 3. Welding 4. Dehogging
  15. 15. Reason of Hogging!
  16. 16. Kinks In Rails When the ends of adjoining rails move slightly out of position, “shoulders” or “kinks” are formed. Measures taken to rectify kinks in rails: 1. By correcting alignment at joints and at curved locations. 2. Proper packing of joints. 3. Proper maintenance of the track periodically in repect of cross levels, gauge, alignment, welding of worn out portions etc.
  17. 17. Buckling of Rails Buckling means the track has gone out of its original position or alignment due to prevention of expansion of rails in hot weather on account of temperature variations.
  18. 18. Damaged Rails These are the rails which should be removed on account of their becoming unsafe for a railway track.
  19. 19. Rail Features • Crushed Heads • Square or Angular Break • Split Heads • Split Web • Horizontal Fissures • Transverse Fissures • Flowing Metal in Heads • Horizontal Cracks
  20. 20. Crushed Head
  21. 21. Split Heads
  22. 22. Horizontal and Transverse Fissures
  23. 23. Flowing Metal in Heads
  24. 24. Rail Joints • Supported Rail Joint • Suspended Rail Joint • Bridge Joint • Base Joint • Welded Rail Joint • Staggered or Broken Joint • Square or Even Joint • Compromise Joint • Insulated Joint • Expansion Joint`
  25. 25. Rail Joint
  26. 26. Insulated Joint
  27. 27. Expansion Joint
  28. 28. Creep of Rails Creep is defined as the longitudinal movement of the rail with respect to the sleepers.
  29. 29. Defects of Creep (i) Sleepers move out of position thereby the rail gauge. (ii) Position of points and crossings are disturbed. (iii) Interlocking mechanism gets disturbed.
  30. 30. Remedies or Prevention of Creep • Pulling back of rails • Provision of Anchors or Anticreepers. • Use of steel sleepers. Anticreeper
  31. 31. Sleepers Sleepers are the transverse ties that are laid to support the rails. They transmit wheel load from the rails to the ballast.
  32. 32. Classification of sleepers (i) Wooden sleeper (ii) Metal sleeper Cast iron sleeper Steel sleeper (iii) Concrete sleeper Reinforced concrete Sleeper (R.C.C) Prestressed Concrete Sleeper .
  33. 33. Wooden Sleepers • Hard wood such as, sal and teak • Soft wood such as, chir and deodar
  34. 34. Metal Sleepers
  35. 35. Concrete Sleepers
  36. 36. Sleeper Density Sleeper density is the number of sleepers Per rail length. It is specified as (M+x) or (N+x), where M or N is the length of the rail in meters and x is a number that varies according to factors such as axle load, speed, type & section of the rail etc. It varies in India from M+4 to M+7 for main tracks.
  37. 37. Track Fittings & Fastenings • Fish plates • Spikes – Dog spikes – Screw spikes – Round spikes – Standard spikes – Elastic spikes • Bolts – Dog or Hook bolt – Fish bolt – Rag bolt – Fang nut and bolt • Keys – Wooden key for C.I. Chair – M.S. key and steel trough sleepers – Stuart’s key – Morgan key – Cotter and tie bars • Chairs – Cast steel chairs – Mild steel and Cast Iron Slide Chairs
  38. 38. • Blocks – Heel blocks – Distance blocks – Crossing blocks – Check blocks • Plates – Bearing Plates – Saddle Plates Track Fittings & Fastenings contd..
  39. 39. Fish Plate
  40. 40. Dog Spike
  41. 41. Screw spikes
  42. 42. Chair
  43. 43. Bearing Plate
  44. 44. Ballast To provide structural support for the track, holding it in good line and surface To distribute the load evenly to the subballast and subgrade and thus help to provide stability Provide for drainage Ballast in railroad terminology is durable granular material placed between the crosstie and the sub ballast to hold the track in line and grade. The primary purposes of ballast are:
  46. 46. Types of Ballast • Broken Stone • Gravel or River Pebbles or Shingle • Ashes or Cinders • Sand • Mooram • Kankar • Brick Ballast • Blast Furnace Slag • Selected Earth
  47. 47. Ballast Size • For wooden sleepers = 5.1 cm • For steel sleepers = 3.8 cm • For under switches & crossings = 2.54 cm
  48. 48. Points & Crossings • Points and crossings provide flexibility of movement by connecting one line to another according to requirements. • They also help for imposing restrictions over turnouts which necessarily retard the movements. • From safety aspect, it is also important as points and crossings are weak kinks or points in the track and vehicles are susceptible to derailments at these places.
  49. 49. Turnouts • It’s the simplest combination of points and crossings which enables one track either a branch line or a siding, to take off from another track. • Parts of a turnout: – A pair of points or switches – A pair of stockrails – A Vee crossing – Two check rails – Four lead rails – Switch tie plate – Studs or stops – Bearing plates, slide chairs, stretcher bars etc. – For operating the points – rods, cranks, levers etc. – For locking system – locking box, lock bar, plunger bar etc.
  50. 50. Types of Switches
  51. 51. Crossings A crossing or a frog is a device which provides two flangeways through which the wheels of the flanges may move, when two rails intersect each other at an angle.
  52. 52. Acute Angle Crossing
  53. 53. Diamond Crossing
  54. 54. Square Crossing
  55. 55. Track Junctions • Turnouts • Symmetrical split • Three throw switch • Double turnout or Tandem • Diamond crossing • Cross overs • Single slip and double slip • Gauntlet track and ladder tracks • Temporary diversion • Triangle • Double junctions
  56. 56. Turnout
  57. 57. Symmetrical split
  58. 58. How Railway Track Changes
  59. 59. Signalling It consists of the systems, devices and means by which trains are operated efficiently and tracks are used to maximum extent, maintaining the safety of the passengers, the staff and the rolling stock.
  60. 60. On the basis of Operating Characteristics: • Detonating Signals (Fog or audible signals) • Hand signals (Visual Indication signals) • Fixed signals (Visual Indication signals)
  61. 61. Detonating Signal
  62. 62. Hand Signals
  63. 63. Fixed Signals
  64. 64. • Stop or Semaphore type Signals • Warner Signals • Shunting Signals (Disc or Ground Signals) • Coloured-light Signals On the basis of Functional Characteristics:
  65. 65. Semaphore type signals
  66. 66. Warner Signals
  67. 67. Shunting Signals
  68. 68. Coloured-light Signals
  69. 69. • Reception Signals – Outer signals – Home signals • Departure Signals – Starter – Advance Starter On the basis of Locational Characteristics:
  70. 70. Departure Signals
  71. 71. • Repeater or Co-acting signals • Routing Signals • Calling on signals • Point indicator • Modified lower quadrant semaphore signal • Miscellaneous signals On the basis of Special Characteristics:
  72. 72. High Speed Bullet Train
  73. 73. THANK YOU