Points, Crossings and Turnouts of Railways.pptx

Engineering

1. Points and Crossings of Railways Understanding the Fundamentals Meet Amin – 22000975 Darsh Shah - 22000976

2. Content Introduction to Points and Crossings of Railway Importance in Railway Infrastructure Turnouts

3. INTRODUCTION TO POINTS AND CROSSINGS OF RAILWAY Points, also known as turnouts, are movable sections of railway track that allow trains to switch from one track to another. Crossings, on the other hand, are fixed sections of track that enable trains to safely cross from one track to another at different levels.

4. IMPORTANCE IN RAILWAY INFRASTRUCTURE Points and crossings are critical components of railway networks, enabling: Route selection for trains to reach various destinations. Diverting trains to sidings for maintenance or allowing faster trains to overtake slower ones. Connecting different railway lines.

5. Turnouts Simplest combination of points and crossings. Enables one track either a branch line or a siding, to take off form another track. OBJECTIVE : To provide facility for safe movement of trains in either direction on both tracks.

6. Parts of Turnouts A pair of points or switches A pair of stock rail A Vee crossing Two check rails Four lead rails Two wing rails Studs or stop Switch tie plate/ Gauge tie chair/ Crossing tie plate Bearing plates, slide chairs, stretcher bars Rods, cranks, levers etc. (for operating the points) Locking box, lock bar, plunger bar (locking system)

7. Types of Turnouts Facing Direction : One standing at the toe of switch and look towards the crossing. Trailing Direction : One standing at the crossing and looks towards the switches. Facing Points of Turnouts : Train passes over the switch first and the over the crossing. Trailing Points of Turnouts : Train passes over the crossing first and then over the switch. Point may be ‘facing’ or ‘tailing’ depending upon the movement of the train.

8. Types Of Turnouts Right Hand Turnout : If the train diverted from main track is diverted to the right of the main route in the facing direction, then the diversion is known as Right Hand Turnout. Left Hand Turnout : If the train diverted from main track is diverted to the left of the main route in the facing direction, then the diversion is known as Left Hand Turnout.

9. Working Principle Of Turnout Works with a combination of points & crossing Consists of : A pair of points or switches Four lead rails Two check rails A crossing

10. A Pair Of Switches Tongue Rail : Tapered with toe at one end & heel at other end. Fixed at heel & move about this point. In one position (F), it leaves a gap with alignment & in other position (L) toe fits closely against alignment. Stock Rail : Position of straight alignment against which the tongue rail fits.

11. A Crossing Connected with ordinary rails to permit the two rail to cross each other. Check rails : Provided on the opposite side of the crossing. To guide the wheel & check the tendency of other wheel to climb over the crossing. Wing Rail : Help in channelizing the wheel in proper routes. Point Rail Nose of Crossing Point where the splice and point rails meet.

12. Points Or Switches

13. Components Of Switches A pair of stock rails A pair of tongue rails Heel block or Distance block Stretcher bar Switch tie plate or gauge tie plate Side chairs or sliding plates Studs or stops

14. Heel Clearance Or Heel Divergence Distance between the running face of stock rail & gauge face of tongue rail, measured at the heel of the switch. Heel Clearance = Flange wat clearance + Tolerance for wear + Width of head of rail

15. Flangeway Clearance Distance between adjacent faces of stock rail & check rail. Provides as a clearance for free movement of wheel flanges.

16. Flangeway Depth Vertical distance between the top surface of running rail to that heel-block used between stock rail and check rail.

17. Switch Angle Also known as angle of Switch Divergence. Angle between the running faces of stock rail & tongue rail. For fast moving train, small switch angle is desirable. Depends on : Heel Divergence Length of tongue rail.

18. Types Of Switches No separate tongue rail. Some portion of track is moved side to side. Not used Tongue rail is combined with the stock rail.

19. Classification Of Spilt Switch Based on fixation at Heel : Loose heel type or articulated type Fixed heel type or spring type or flexible type Based on cut provided : Under cut switches Over riding switches Straight cut switches

20. Loose Heel Type : Tongue rails are joined to lead rails by fish plates. 2 front bolts are kept loose to allow throw of switch. Bolts are kept tight when the tongue is open. Suitable for short length switch. Fixed Heel Type : Improvement of loose heel type. All 4 bolts are tight when the tongue is closed. Suitable for long tongue rails.

21. Under Cut Switch Straight Cut Switch Over-riding Switch

22. Crossings A device which provides two flangeways through which the wheels of the flanges may move, when two rails intersect each other at an angle. Flanged wheels jump over the gap from 'throat' to 'nose' of crossing. Wheel flanges are guided by 'check rails' to prevent striking the nose.

23. Components of Crossings A crossing or Vee piece Point & Splice rails Wing rails Check rails Chairs at crossing, toe & heel Blocks at throat, nose, heel & distance block Packing below wing rails at toe & throat

24. Types Of Crossings Acute Angle Crossing

25. Types Of Crossings Obtuse Angle Crossing

26. Types Of Crossings Square Crossing

27. Types of Crossings Spring or Movable Crossing

28. Types of Crossings Ramped Crossing

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