design of turn out THEORY.pptx

design of turn out THEOry

1. Design of TURNOUT INTERSECTION POINT TNC

2. Tangential type

3. INTERSECTING TYPE

4. Tongue Rail Stock Rail Switch Entry Angle Switch Entry Angle Straight Switch Curved Switch TTS ATS Switch Entry Angle

5. Switch Entry Angle for Switches (BG) 1 in 8.5 curved (PSC) 0 o - 46 ’ - 59 ” 1 in 12 curved (PSC) 0 o - 20 ’ - 00 ” 1 in 16 curved (PSC) 0 o - 20 ’ - 00 ” 1 in 20 curved (PSC) 0 o - 20 ’ - 00 ”

6. d c = heel clearance d = heel divergence Heel Divergence & Heel Clearance c

7. Heel Divergence BG(1 in 8.5 CU SW, PSC sleeper ) 182.5mm BG(1 in 12, CU SW, PSC sleeper ) 175mm

8. Heel Divergence B T A C AC = AB + BC AB = TA Tan( θ ) , BC = TA x TA / (2 R) θ

9. TURN-IN-CURVE TURN-IN-CURVE (CONNECTING CURVE ) STRAIGHT CROSSING LEAD CURVE (TURNOUT CURVE ) MAIN TRACK

10. Turnouts on Concrete Sleepers Sleeper Orientation Switch Portion- Perpendicular to main line Lead Portion- Laid with their axis at an angle of  /2 with the perpendicular to the main line where,  is the angle between the perpendicular to main line and the perpendicular to the tangent drawn on gauge face of outer rail of turnout at that point (  goes on increasing towards crossing) Crossing Portion- Sleepers axis perpendicular to bisector of crossing angle. (spacing along the bisector of crossing angle)

11. SLEEPER SPACING - LEAD PORTION

12. SLEEPER SPACING – CROSSING PORTION

13. Features of Turnouts on Concrete Sleepers Spacing (ORS) Uniform spacing except for the sleepers near ATS ( to accommodate S & T fittings)

14. 90-/2   90-/2 RE RE Interchangeability of Sleepers on LH/RH Turnouts

15. RE RE Interchangeability of Sleepers on LH/RH Turnouts

16. Fan Shaped Layout Conventional Layout

17. Orientation of Sleeper in Fan Shaped Layout

18. Marking on PSC Sleepers for Points and Crossings

19. Tongue Rail

20. 6 28 6 22 12R Q Bottom of Tongue Rail Bottom of Stock Rail Top of Tongue Rail Top of Stock Rail JOH 13 6 mm High Tongue Rail 144 156.4 172 1682 5840 Head Width 13mm Vertical Planning Of Tongue Rail 60 Kg UIC, 1 in 12 Turn Out 4244 166 Level Point Head Width 43.3 mm 43.3

21. 1 in 12 Curved Switch (RDSO/T-4218, 60kg,PSC) Pre-Curving of Tongue and Stock Rail ATS SRJ ATS

22. 30 11856 40 30 43 32 32 12356 1144 T-4218 for 1 in 12, 60kg

23. 69 52 52 23 23 31 7620 T-4865 for 1 in 8.5, 60/52kg

24. Points and Crossings are laid without Cant Approach rails are Canted (1 in 20) Improper fishing at SRJ and Heel of Crossing R everse canting of sleepers in 4 sleepers On all three sides 1AS, 2AS, 3A, and 4A (Before SRJ) 1E, 2E, 3E, and 4E (Beyond Heel of Crossing) (on both Straight and Turnout side) Running out Cant on Approaches

25. Running out Cant on Approaches

26. Running out level difference between SR and TR behind Heel of switch

27. PROVISIONS IN IRPWM The tongue rail and stock rail shall be fabricated in workshop as per standard RDSO drawings. Field officials should check the curvature of Stock Rail and Tongue Rail before laying. In case of Turn out taking off from curve suitable curvature as per resultant lead radius to be provided both in Stock Rail and Tongue Rail. The versine at each station in lead curve and turn in curve should not be beyond 3 mm, from its design value, as a good maintenance practice.

28. DESIGN VERSINE FOR 1 IN 8.5 T/O

29. DESIGN VERSINE FOR 1 IN 12 T/O

30. Running Rail Gauge Face 1415 1415 4330 1500 227.5 875 1500 227.5 41 68.75 Check Rail Machined Check Rail Check Rail Flare 1 in 70

31. Check Rail Clearance Tighter clearance causes wear on check rail & slackness causes wheels to strike ANC & wear of nose of crossing.

32. Check Rail Clearance c < G – g – t max For Gauge 1676 mm = 1676 - 1600 - 28.5 = 47.5 mm ( max.) (Limits as per SOD 48 to 44 mm ) For Gauge 1673 mm = 1673 – 1600 – 28.5 = 44.5 mm (Limits as per SOD 45 to 41 mm ) Check Rail clearance

33. Various factors limiting speeds over turnouts are as follows: A-Kink in the turnout route at the toe of switch rail B-Entry from straight to curve without transition – This is eliminated in curved switches C- Lead curve without super-elevation D-Entry from curve to straight without transition E-Gap at the V of crossing

34. 1- Turnout with straight switches

35. Offsets to Lead Curves for Turnout with Straight Switches - The lead curve is extended from heel at point ‘B’ to a point ‘H’ so that the tangent to the curve runs parallel to the gauge line at a distance ‘Y’

36. Example

37. 2- Turnout with Curved Switches The lead curves in these layouts starts at toe of switch, are tangential to the switch angle and meets the straight leg of crossing at a distance ‘w’ from the TNC of the crossing iiikkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk

38. At toe of switch, thickness of tongue rail is ‘t’. Derivation for lead curve radius will be same as for straight switches. The same can be derived by substituting ‘t’ (toe thickness) for ‘d’ (the heel divergence).

39. - Example Calculate the lead and the radius of a 1 in 12 turnout with curved switches.