1. Sleepers A Presentation on Department of Civil Engineering,
M.S.P.V.L.Polytechnic College,
Pavoorchatram

2. Sleepers are members generally laid transverse to the rails, on which the rails are fixed to transfer the loads from the rails to the ballast and the subgrade.

3. Main function of Sleepers
Holding rails to correct gauge and alignment.
Firm and even support to rails.
Transferring the load evenly from rails to wider area of ballast.
Elastic medium between rails and ballast.
Providing longitudinal and lateral stability.

4. Types of Sleepers Wooden Sleepers Cast Iron Sleepers Steel Sleepers
Concrete Sleepers

5. Classification of wooden sleepers
Untreated Sleeper – ‘U’
Treated Sleeper – ‘T’

6. Advantages/Disadvantages of wooden Sleepers
Easy to manufacture and handling.
Suitable for track circuited area.
Can be used with or without ballast.
Suitable for bridges, Points/Crossings.
Suitable for gauntleted track.
Alignment can be easily corrected.

7. Disadvantages:
i) Lesser life. ii) Liable to damage by beater packing. iii) Difficult to maintain the gauge. iv) Susceptible to fire hazards.

8. Description of Wooden Sleepers
Size of wooden sleepers in mm : B.G. : For ordinary track 2750x250x130 (9’x10”x5”) Durable and non durable types of sleepers. Life of Sleeper: Durable –19 years (B.G.)/ 31 years (M.G.) Non-Durable- 12 to16 years.

9. Cast Iron Sleepers A) C. I. Pot Sleepers B) C S T- 9 Sleepers
Type of Cast Iron Sleepers:
A) C. I. Pot Sleepers
B) C S T- 9 Sleepers
Advantages of Cast Iron Sleepers:
i) Lesser corrosion.
ii) Easy handling due to light weight.
iii) Higher Scrap value.

10. Pot sleeper

11. CST-9 Sleeper

12. Contd. …
Disadvantages of Cast Iron Sleepers: i) Not suitable for high speed route. ii) Difficult to maintain the Gauge. iii) Lesser lateral stability. iv) Not fit for track circuited area. v) Not suitable for mechanical maintenance. vi) Tie bars weakened by corrosion.

13. Usual defects in CST-9 Sleepers
Cracks at rail seats or fracture
Wear of lug and rail seat
Tie bars weakened by corrosion, broken or damaged by falling of wagon parts.
Corrosion of tie bars inside the cast iron plates.

14. ST Sleeper

15. Steel trough Sleepers
Types of S.T. Sleepers i) ST sleepers with Pressed up lugs. ii) ST Sleepers with loose jaws. iii) Bolt and clip type ST Sleepers. iv) Special ST Sleepers for Turn out. v) ST Sleepers with pad plates for use with elastic rail clip.

16. ST Sleeper with pressed up lug

17. ST Sleepers with loose jaws

18. Contd. …
Advantages of ST Sleepers: i) Longer life ii) Better Stability iii) Lesser damage during handling /Transport iv) Easy to maintain Gauge v) Simple Manufacturing Process vi) High Scrap value

19. Contd. …
Disadvantages of ST Sleepers: i) Liable for corrosion. ii) Not fit for track circuited area. iii) Develops cracks at rail seat during service. iv) Can only be used for rails for which it is manufactured.

20. Usual defects in ST Sleepers Rusted and corroded metal
Cracks at rail seat or near the lugs
Elongation of holes
Inspection of sleepers- Over 20 years old
Precautions during maintenance
Reconditioning of sleeper

21. Concrete Sleepers
Types of concrete Sleepers: i)Mono-block Prestressed Concrete Sleepers. a) PSC-12 for 52 Kg Rails b) PSC-14 for 60 Kg Rails ii) Two block reinforced concrete Sleepers.

24. Contd. …
Advantages of concrete Sleepers: i) Greater stability. ii) Track geometry maintained for much. longer duration hence economical. iii) Best suited for machine maintenance. iv) Suitable for Track circuiting area.

25. Contd. …
v) No chances of damage by fire/ corrosion vi) No possibility of theft. vii) No chances of gauge widening. viii) 60 Kg Sleeper can be used for 52 Kg rail. ix) Best suited for LWR track. x) Best performance on P & C, S.E.J. Guard rails , Level Crossings, Check rail in curve.

26. Contd. … Disadvantage : Handling and laying is difficult being heavy.
Damage is very heavy in case of derailment.
No scrap value.
Not suitable for manual packing.

27. Contd. … Conditions for laying Concrete Sleepers:
i) Track should be deep screened.
ii) Cuttings having rocky bed should have clean ballast cushion of at least 300 mm.
iii)On Arch bridges formation cover min. 1 m.
iv) On other bridges ballast cushion not less than 300 mm.

28. The End
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