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Introduction to Rails and Joints

Introduction to Rails and Joints. AIM. TO UNDERSTAND Track structure History of rail Functions of rail ,Components of the rail Material and properties of rail Grade of rail and its identification Dimensional tolerances Rail closures Causes of rail deterioration Rail joints.

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Introduction to Rails and Joints

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  1. Introduction to Rails and Joints

  2. AIM • TO UNDERSTAND • Track structure • History of rail • Functions of rail ,Components of the rail • Material and properties of rail • Grade of rail and its identification • Dimensional tolerances • Rail closures • Causes of rail deterioration • Rail joints

  3. HISTORY OF RAIL TRANSPORT • 1825 – First train journey - Stockton to Darlington, U.K • 1833 – Mohawk to Hudson, USA. • 1835 – Nuremburg to Furth, Germany. • 1853 – Bombay to Thane, India.

  4. HISTORY • The earliest record of use of track for transportation comes from England where in 1604 ,a railway was constructed from a coal mine to river Tyne.The track were made of wooden rails upon which carts with wooden wheels were Pushed/Pulled by man or horse . • In the late 1760s, It was began to fix plates of cast iron to the upper surface of the wooden rails. • By 1776, iron had replaced the wood in the rails and wheels on the carts.

  5. HISTORY ………………….. • Wagonways evolved into Tramways and spread though out Europe. • Another system was introduced, in which unflanged wheels ran on L-shaped metal plates - these became known as plateways. • The earliest of these in general use were the so-called cast iron fishbelly rails from their shape

  6. HISTORY …………………. • For a long time ,double headed and bull headed rails were popular in world railway system • About 80 years ago , flat footed rails were introduced. • The performance of these rails has found to be superior to all previous types of rails.

  7. HISTORY ……………………….. • The introduction of process for making cheap steel led to the era of great expansion of railways that began in the late 1860s. Steel rails lasted several times longer than iron.

  8. Conversion of Bloom to Rail

  9. Functions of rail • To offer hard and unyielding surface to the rolling rigid wheel on it. • To act as beam and transmit the wheel loads to the sleepers. • To steer the wheels in the desired direction.

  10. Components of Rail • Head:- Bears the load and allow wear during service • Web:-Bear the load and allow wear due to corrosion • Foot:-To give stability against overturning and distribute load over large area of the sleeper surface

  11. INDIAN RAILWAYS STANDARD SPECIFICATION FOR FLAT BOTTOM RAILWAY RAIL

  12. RAIL MATERIAL

  13. ROLE OF ALLOY METALS IN RAIL STEEL • Carbon:- • 1) Increases the tensile strength of steel • 2) Increases the hardness of steel • 3) Lowers the melting point of steel • 4) Makes steel easier to harden with heat treatments • 5) Lowers the temperature required to heat treat steel • -1) Decreases the ease with which steel can be machined • -2) Decreases the ductility of steel • -3) Increases the difficulty of welding steel

  14. ROLE OF ALLOY………………… • Manganese:-Increase hardness thereby improving strength and toughness. • Silicon& Aluminum:-Useful in killing the steel(Removal of excess oxygen from steel). • Chromium, Copper:- Increases corrosion resistance.

  15. ROLE OF ALLOY………………… • Molybdenum:- Increases the toughness of steel. • Nickel:- Increases the toughness, corrosion resistance of steel. • Vanadium:- Increases strength while retaining ductility of steel. • Niobium:- Increases the toughness, strength, formability, and weldability of the steel.

  16. ROLE OF ALLOY………………… • Injurious alloy metals:- • Sulphur:-decreases ductility and notch impact toughness especially in the transverse direction, weldability decreases with increasing sulfur content. • Nitrogen and Hydrogen:-make steel brittle. • Phosphorus:-increases strength and hardness but decreases ductility and notch impact toughness of steel. 

  17. Brand marks Brand mark shall include: • Rail section • The Grade of steel • Identification mark of manufacturer • Month (using Roman numbers) and last two digits of year of manufacture • Process of making (O –Basic oxygen or E- electric) (Brand mark will be rolled at every 3.0m)

  18. Grade of steel

  19. Rail Section of rails

  20. Main Dimensions of Rails

  21. Permissible Wear on Rails(Para-302) • Vertical Wear

  22. Contd. …. • Lateral Wear

  23. Quality of Rails (C.S.No-117) • Prime Quality Rails: New Rail as per IRS-T-12/09( Its latest version). These rails are further classified based on tolerance in end straightness as under- • Class ‘A’ Rails • Class ‘B’ Rails • ‘Industrial Use Rails’ : Rails with relaxation in sectional tolerance as provided in Amendment to IRS – T-12/09 but otherwise conforming to T-12/09 in all other respects i.e. Chemical composition, mechanical properties etc. These rails can be used in Industrial siding with speed restriction of 50 Kmph

  24. Identification of different qualities of Rails (As per T-12/09)

  25. Standard length and Identification for new Rails

  26. COLOUR CODING Prime 13 m Prime 12 m Prime 11 m Prime 10 m IU 13 M IU 11 M REJECTED

  27. Prime quality rail (Paint marking for quality & length)

  28. IU quality rail (Paint marking for quality & length) & stamping I U

  29. Standard sections of Rails (CS-117 dated 19.05.09)

  30. Contd. …..

  31. Rail Closure (Para-256) • A rail piece of less than the standard length, used in the track for closing a rail gap, is called rail closure. The shortest length of rail closure to be used in the track as a permanent measure is 5.50 m. • On following locations and 500m approaches on both side, minimum length of closure is 11m. Tunnel, Deep cutting, Major & Important bridges and high embankment

  32. Guide lines for using closure • Limited use. • Only hacksaw cut, no gas cut. • Avoid on junction of different types of rails and/or sleepers. • Avoid on bridges, level crossings and points and crossings. • Better not to use opposite to each other.

  33. Causes of Rail Deterioration (Para- 249) 1) Corrosion and rusting (Generally noticed on web & foot of rail) Locations Prone to corrosion : i) Platform lines. ii) Sidings where corrosive goods are dealt. iii) Tunnels and damp cuttings. iv) Coastal area. v) Industrial belts.

  34. Contd. … 2.Wear on Rail Table : • Normally of very small order. • Amount of wear increases with heavy traffic density as in suburban section. 3. Flattening of rail table: • Mostly occurs on the inner rail of a curve. • Indication of over loading

  35. Contd. … 4. Wear on Gauge Face: • Noticed on outer rail of a curve. • Due to heavy pressure from the wheels which results in the running edge becoming worn or ‘side-cut’. • Specially in suburban sections where multiple unit coaches are provided.

  36. Contd. … 5. Hogging of Rail Ends: • A hogged rail is one with its end or ends bent in vertical direction. • Due to bad maintenance of joints. • Due to unserviceable sleepers on joints.

  37. Contd. … 6. Battering of Rail Ends: • Occurs where the gap on fish plated joints are excessive. • Caused by impact of wheels on end of a rail particularly if the fishplates do not fit snugly.

  38. Contd. … 7.Wheel burns: • Wheel slipping occurs usually on adverse gradient or while starting on raising gradient. • Heat is generated and depression is caused on rail table known as wheel burns. • Also occur due to sudden application of brakes.

  39. Contd. … 8.Corrugation: • Rail table develops hollows and ridges. • Also known as “Roaring rails”. • Excessive vibrations are caused. • Fastening and packing tends to get loose. • Track needs frequent attention.

  40. Service Life of Rails

  41. Drilling of holes in rails

  42. Drilling of holes in rails • The position of hole in rail is at a specified distance from the base of the rail and not in the centre of the web. • the proper drilling of a hole should be ensured by making use of template. • Punch should be used for making the hole centres on the web. • The permissible tolerance is only 0.8mm

  43. Drilling of holes in rails

  44. Rail Joints Requirement • It should hold the rail ends in the correct position, both in the horizontal and vertical planes. • It should provide elasticity equal to that of the rail. • It should allow free expansion and contraction of the rail. • As the contact surfaces wear out under traffic, necessary adjustment in the joint should be possible to retain level and line.

  45. Rail Joints Requirement …………….. • The joint components, i.e. fishplates, bolts and nuts, should not be very heavy. • It should be easy to maintain and the cost of maintenance should be minimal. • The cost factor should always be borne in mind because nearly 25 percent of the track maintenance cost in other than LWR tracks is for the joints alone. • It should permit easy replacement of any single rail from the track.

  46. Suspended or supported joint • Supported Joint • Suspended Joint • Bridging Joint • Which is better ?

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