Sleepers Ppt

A Presentation on

Sleepers

Department of Civil Engineering,M.S.P.V.L.Polytechnic College,

Pavoorchatramwww.ustudy.in

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.www.ustudy.in

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.www.ustudy.in

Types of Sleepers

Wooden Sleepers Cast Iron Sleepers

Steel Sleepers Concrete Sleepers

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Classification of wooden sleepers

Untreated Sleeper – ‘U’

Treated Sleeper – ‘T’

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Advantages/Disadvantages of wooden Sleepers

Advantagesi) Easy to manufacture and handling.ii) Suitable for track circuited area.iii) Can be used with or without ballast.iv) Suitable for bridges,

Points/Crossings.v) Suitable for gauntleted track.vi) Alignment can be easily corrected.

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Disadvantages:

i) Lesser life.ii) Liable to damage by beater

packing.iii) Difficult to maintain the gauge.iv) Susceptible to fire hazards.

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Description of Wooden SleepersSize 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.

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Cast Iron 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.

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Pot sleeper

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CST-9 Sleeper

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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.

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Usual defects in CST-9 SleepersCracks at rail seats or fractureWear of lug and rail seatTie bars weakened by corrosion,

broken or damaged by falling of wagon parts.

Corrosion of tie bars inside the cast iron plates.

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ST Sleeper

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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.

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ST Sleeper with pressed up lug

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ST Sleepers with loose jaws

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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

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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.

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Usual defects in ST SleepersRusted and corroded metalCracks at rail seat or near the lugsElongation of holesInspection of sleepers- Over 20

years oldPrecautions during maintenanceReconditioning of sleeper

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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.

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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.

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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.

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Contd. …

Disadvantage :i) Handling and laying is difficult

being heavy.ii) Damage is very heavy in case of

derailment.iii) No scrap value.iv) Not suitable for manual packing.

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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.www.ustudy.in

The End

THANK YOU

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