Basics of Railway track and its components.

2. :

4. Load Transfer

5. Important Functions of Ballast
 To transfer and distribute the load form sleepers to a
larger area of formation.
 To provide elasticity and resilience to track for getting
proper riding comfort .
 To provide necessary resistance to track for
longitudinal lateral stability .
 To provide effective drainage to track.
 To provide effective means of maintaining evenness
and alignment of track

6. Standard Ballast Profile

7. Advantage of Traditional Ballasted Track
Advantage
•
•
•
•
Relatively low construction costs.
High elasticity.
High maintainability at relatively low costs.
High noise absorption.

8. Disadvantage of Traditional Ballasted
Track
Disadvantage
• Over time, track tends to ‘float’, in both longitudinal and
lateral direction, as a result of non linear, irreversible
behaviour of the materials.
• Limited non-compensated lateral acceleration in curves, due
to limited lateral resistance offered by the ballast.
• Ballast can be churned up at high speeds, causing serious
damage to the rails and wheels.
• Reduced permeability due to contamination, grinding down of
ballast and transfer of fine particles from sub grade.

9. • Ballast is relatively heavy, leading to an increase in costs of
building bridges and viaducts, if they are to carry continuous
ballasted track.
• ballasted track is relatively high, this direct consequences on
tunnel diameter and access points.

10. Advantage of Ballastless Track
• Reduced Height
• Lower maintenance requirement and hence,
higher availability for train operation
• Increased service life
• Lack of suitable ballasted material
• A requirement for track to cause(even) less
noise and vibration nuisance

11. • Ballastless tracks are the good options for high speed
heavy haul trains; but on the other hands they are
costly also.

12. PRINCIPAL FEATURES OF
PERMANENT-WAY
12

13. rails
Sleepers
Ballast
Embankment
Function
•Support & guide vehicles running on it
13

14. •Conventional Track
•Consists of two “Rails” located at a fixed distance apart
•Called “Gauge”
•The Gauge of a track is the distance between inner edges of the
heads of rails in track, measured at 16mm below the top surface
of the rail.
14

15. Rails
Rails are members of the track laid in two parallel lines to provide
on our continuous and land surface for the movement of
Trains.
Function of rails
(a)
(b)
(c)
(d)
(e)
Provide a continuous and level surface
Provide a pathway which is smooth and less friction
Lateral guide for the wheels
Bear changes due to vertical loads etc.
Transfers to formation through sleepers on wider area.
15

16. 16

17. Coning of wheels – The distance between the inside edges of
wheel flanges is generally kept less than the gauge. Gap is
about 38 mm on Either side. Normally the tyre is absolutely
ahead centre on the head of the rail, as the wheel is coned to
keep it in this central position automatically. These wheel are
coned at a slope
Theory of coning:- On a level track, as soon as the axle moves
towards one rail, the diameter of the wheel tread over the rail
increases, while It decreases over the other rail. This prevents
to further movement And axle retreats back to its original
position ( with equal dia or both rails and equal pressure on
both rails).
17

18. • Advantages of coning of the wheels are :1. To reduce the wheel and tear of wheel flange
and rails which due
• To rubbing action of flanges with inside to
cess of the rail head.
2. To provide a possibility of lateral movement.

19. Sleepers
Sleepers are transverse ties that are laid to support the rails. They
Have an important role in the track as they transmit the wheel load
From the rails to the ballast.
Functions and requirement of sleepers
(a) Holding the rails to their correct gauge alignment
(b) Giving a firm and ever support to the rails
(c) Transfering the load evenly from rails to a wider area of the ballast.
(d) Providing longitudinal and lateral stability the permanent way.
Sleeper density and spacing of sleepers
Sleeper density is the number of sleeper per rail length. It is M +X
Specified on where
M– length of the rail
19

20. Sleeper Density
• M+4 low density traffic < 10 GMT & D & E
routes
• M+7
– M is the rail length for 13 m rail length M+7 =20
• For Long Welded Track 1540 sleepers per Km
or 1660 sleepers per Km
20

21. Concrete Sleeper
Pre-Stressed Concrete Sleeper (PSC)
21

22. REQUIREMENT OF SLEEPER
• IT SHOULD PROVIDE EASY MEANS OF MAINTAINABILITY
•
HANDLING OF RAILS, SLEEPER & FASTENING SHOULD BE EASY
• QUICK RESTORATION AFTER ACCIDENT IS POSSIBLE
•
MATERIAL AND DESIGN IS AVAILABLE
•
IT SHOULD HAVE ANTI THEFT AND ANTI-SABOTAGE QUALITY
•
IT SHOULD BE OVERALL CHEAP

23. LOAD DISTRIBUTION FROM AXLE TO SLEEPERS

24. DESIGN CONSIDERATIONS
• THE REACTION AT THE RAIL SEAT DEPENDS
UPON------– SLEEPERS SPACING
– AXLE LOADS
– SPEED OF TRAINS
– THE STANDARD OF MAINTENANCE OF TRACK

25. DESIGN CONSIDERATIONS
• TO CALCULATE THE FORCES TO WHICH THE
CONCRETE SLEEPERS ARE SUBJECTED
IS
COMPLICATED AND IS GENERALLY BASED ON
OBSERVATIONS,
EXPERIENCE
AND
MEASUREMENTS.

26. DESIGN CONSIDERATIONS
• FOR BG (22T AXLE LOAD), A WHEEL LOAD OF 11 T
AT THE RAIL TOP WILL CAUSE A VERTICAL SLEEPER
REACTION OF 6 T.
• FOR MG (14T AXLE LOAD), THIS VALUE IS 5 T.
THESE LOADS ARE AUGMENTED BY 150% TO CATER
FOR DYNAMIC AUGMENT FOR DESIGN PURPOSE.

27. CONDITION NO. 1
NO CENTRE BINDING
15 TONNE
15 TONNE
1750 MM
p
670MM
1040 MM
1040 MM

28. CONDITION NO. 2
WITH CENTRE BINDING
15 TONNE
15 TONNE
1750 MM
p’
p’
670MM
1040 MM
1040 MM

29. CONDITION NO. 3 : Lateral load
13 TONNE
7 TONNE
1750 MM
p

30. DESIGN CONSIDERATIONS
1.237
CONDITION 2
B.M.
CONDITION 3
CONDITION 1
1.277

31. DESIGN CONSIDERATIONS
• MAX. B.M. AT RAIL SEAT IS GOVERNED BY
CONDITION NO.1
• MAX. B.M. AT CENTRE IS GOVERNED BY
CONDITION NO.2
• CONDITION NO.3 DOES NOT GOVERN THE
MAX. B.M. AT ANY LOCATION AND HENCE
IS NOT CONSIDERED

32. SHAPE OF SLEEPER IN PLAN –
– SHOULD NOT ALLOW CONCENTRATION
OF THE BALLAST REACTION IN MIDDLE
HENCE TRAPEZOIDAL SHAPE
ADDITIONAL LATERAL RESISTANCE DUE
TO WEDGING ACTION

33. SHAPE OF SLEEPER IN PLAN
•SLEEPER PROFILE IS TRAPEZOIDAL BECAUSE
IT IS HAVING MORE SECTION MODULUS COMPARED
TO RECTANGULAR SECTIONS WITH SAME CROSS
SECTIONAL AREA.
IT ALSO FECILITATE EASY DEMOULDING AND
MORE ROOM FOR HTS WIRES AT THE BOTTOM.

34. ADVANTAGES OF PSC SLEEPERS
• HEAVY WEIGHT--PROVIDES LONGITUDINAL & LATERAL
STABILITY REQUIRED FOR LWR
• WITH ELASTIC FASTENING, IT CAN MAINTAIN GAUGE
AND ALIGNMENT PROPERLY, HENCE MORE SAFE
• FLAT BOTTOM –SUITES MECH. TAMPING
• COST EFFECTIVE
• DURABLE--IMMUNE TO TERMITE, FIRE, RUSTS, ETC.
• ANTI THEFT & ANTI-SABOTAGE
• SUITED FOR TRACK CIRCUITING

35. DISADVANTAGES OF PSC SLEEPERS
LAYING & HANDLING IS DIFFICULT AS IT IS HEAVY
DIFFICULT TO RESTORE TRAFFIC AFTER ACCIDENT
NOT AMENABLE TO MANUAL LAYING OR MAINT.
REQUIRES MORE BALLAST AND WIDER FORMATION
NO SCRAP VALUE- DIFFICULT TO DISPOSE
MAINTENANCE OF JOINT IS DIFFICULT
NOT UNIVERSAL --USE OF DIFF. TYPE OF SLEEPERS

36. FUNCTIONS OF SLEEPER ASSEMBALY
• TRANSMIT AXLE LOAD OF VEHICLES TO
BALLAST PROPERLY
• HOLD
– GAUGE
– LEVEL
– ALIGNMENT
• PROVIDING LONGITUDINAL & LATERAL
STABILITY TO TRACK

37. Fishplate
– To provide continuity across rail joint for the
movement of railway vehicles
– Rail ends are connected by “fishplates” & “fish
bolt”
37

38. FASTENINGS
• Fixing
arrangement for
Rails and
sleepers
• Various types
• Depending on
type of Rails &
Sleepers,
38

39. FASTENING
• UIC ORE DEFINITION
– FASTENINGS OR FASTENING DEVICES ARE DESIGNED AS
THAT ASSEMBLY OF PARTS , ENSURING THE CONNECTION
BETWEEN RAILS AND SLEEPERS OR RAIL BEARERS IN THE
CASE OF TRADITIONAL TRACK LAYING SYSTEM OR WITH
SUBSTRUCTURE IN CASE THE TRACK IS LAID DIRECTLY ON
THE STRUCTURES OR ON THE TUNNEL BASE.

40. FASTENING TYPES
• VARIOUS TYPES
–RAIL FREE
–RIGID
–ELASTIC

41. FASTENING (FORCES)
• FORCES IN TRACK
– DOWNWARD FORCES: SLEEPER UNDER
LOAD,THERE WILL BE A TENDENCY OF GAP
BETWEEN RAIL AND FASTENING - FASTENING
PREVENTS THIS
– UPWARD FORCES: LOAD AWAY FROM
SLEEPER, TRACK TENDS TO LIFT UPWARD,GAP
BETWEEN RAIL AND SLEEPER – FASTENING
PREVENT THIS

42. FASTENING (FORCES)
– ROTATION OF SLEEPERS: ROTATION OF SLEEPERS
ABOUT ITS OWN AXIS - FASTENING TO PREVENT THIS
– LATERAL FORCES: DUE TO PARASITIC MOTIONS AND
DUE TO LONGITUDINAL COMPRESSION(DURING
BUCKLING)– RAIL HAS TENDENCY TO MOVE LATERALLY
ON SLEEPER AND SOMETIME COMPLETE TRACK MOVE
LATERALLY-FASTENING SHOULD PROVIDE BUCKLING
STRENGTH AND TORSIONAL STRENGTH

43. FASTENING (FORCES)
• LONGITUDINAL FORCES: CAUSED BY THERMAL
STRESSES,WAVE ACTION AND ADHESION
BETWEEN RAIL AND WHEEL.THESE FORCES MAY
CAUSE MOVEMENT OF RAIL OVER SLEEPER OR
MOVEMENT
OF
ENTIRE
RAIL/SLEEPER
ASSEMBLY--FASTENING SHOULD PREVENT THIS.
DOWNWARD LOAD ON TOE OF RAIL CAUSED BY
ELASTIC FASTENING IS CALLED TOE LOAD.

44. FASTENING (FORCES)
– VIBRATIONS- LOW FREQUENCY DUE TO
PARASITIC MOTION and VERY HIGH
FREQUENCY VIBRATIONS IN VERTICAL PLANE
DUE TO RAIL WHEEL INTERACTION 700 TO
1200 CPS AND AMPLITUDE OF 0.1 MM TO 0.3
MM WITH ACCELRATION OF 70 TO 100 g

45. EFFECTS OF VERY HIGH FREQUENCY
VIBRATIONS
– CAUSE OF FATIGUE FAILURE
– LOOSENING OF FASTENING
– LOOSENING OF BALLAST
– LOSS OF TOE LOAD
– EFFECT ON ROLLING STOCK
– RAIL CORRUGATION
THE FASTENING SHOULD ABSORB
AND DAMP THE HIGH ENERGY VIBRATIONS.

46. ELASTIC FASTENING
• RAIL IS CONNECTED WITH SLEEPER THROUGH AN
ELASTIC MEDIUM, SUCH THAT IT ABSORBS ENERGY
OF VIBRATIONS AND DOES NOT ALLOW TO CAUSE
GAP BETWEEN RAIL AND SLEEPERS.
• THERE SHOULD BE DAMPED ELASTIC SUSPENSION
WITHOUT PLAY. THE FASTENING PERMITS THE
MOVEMENT OF RAIL WITHOUT CAUSING ANY GAP.

47. TYPE OF ELASTIC FASTENING
• TYPE I – IN WHICH TOE LOAD IS DERIVED FROM
A FRICTIONAL GRIP OR NAILING EFFECT
• ERS, DS 18 AND MACBETH
• TYPE II – IN WHICH LOAD APPLICATION IS
OBTAINED THROUGH A SCREW THREAD
• HM, NABLA, VASSLOH
• TYPE III – IN WHICH THE LOAD IS
PREDETERMINED AT THE DESIGN STAGE
• PENDROL

48. OBJECTIVES OF ELASTIC FASTENING
• ELASTIC RUBBER PAD
• ABSORBS SHOCKS AND DAMP OUT VIBRATIONS
• INCREASE FRICTIONAL RESISTANCE TO LONG. OR
LATERAL MOVEMENT OF RAIL.
• DISTRIBUTE LOAD UNIFORMLY OVER SLEEPER
• PROVIDE ELECTRIC INSULATION BETWEEN RAIL
AND SLEEPER
• REDUCE NOISE LEVEL

49. MECHANISM
Weight of rail
Source of
Vibration
Vibration blocked by fastening
spring
Rail
Fastening
GRP
Sleeper
Ballast
Wt of
sleeper
Vibration absorbed by rubber pad
Vibration absorbed
By stone friction &
Spring action

50. MECHANISM
LOAD
ENERGY
ABSORBED
ERC & GRP 60 %
BALLAST 25%
FORMATION
15%

51. VOSSLOH FASTENING
Sleeper screw
in dowel
Tension clamps
Guide plate
Rail Pad

52. COMPARISION BETWEEN ELASTIC
FASTENING
TYPE II (BOLTED FASTENER)
TYPE III ( CAST IN ANCHORAGE
FASTENER)
THREADED ELEMENT APPLYING ANCHORAGE FIXED AT THE TIME
FORCE TO A SPRING STEEL
OF CASTING
ELEMENT
THREADED ELEMENT IS
-------REMOVABLE
RUBBER PAD BETWEEN RAIL
RUBBER PAD BETWEEN RAIL AND
AND SLEEPER
SLEEPER
TOE LOAD GENERATED BY
NO SUCH PROVISION
TIGHTENING NUT
ADJUSTABLE TOE LOAD
FIXED TOE LOAD
ALLOWS REPLACEMENT OF
CASTING ANCHORAGES CANNOT
ALL THE COMPONENTS IN THE BE RENEWED
EVENT OF DAMAGE
OILING OF THREADS ONCE IN 3 NO NEED.FIT AND FORGET TYPE
YEARS

53. REQUIREMENT OF TOE LOAD
• ERC MARK III HAS AV. TOE LOAD OF 1000 KG
UNDER 12 MM. DEFLECTION.
– THE AV. STATIC TOE LOAD =1000x4 =4000 KG.
ASSUMING 0.5 AS COEFF. OF FRICTION BETWEEN
RUBBER PAD AND RAIL, THE RAIL TO SLEEPER
RESISTANCE IS APPROX. 2000 KG.
– THIS IS > AV. SLEEPER TO BALLAST RESISTANCE ( 1000
KG.). SO THE CHANCES OF RELATIVE RAIL TO SLEEPER
MOVEMENT ARE LESS.

54. WHY GREASING?
LOADED
CONDITION
AXLELOAD
22 Tons
FREE
CONDITION
FREE
CONDITION
TOE LOAD
850-1100Kg
TOE LOAD
850-1100Kg
Minimum
Compressive
stress
Maximum
Compressive
stress
Minimum
Compressive
stress

55. WHY GREASING?
Figure shows the torsional
force exerted due to
corrosion.
Torsional Force
ERC
ERC
CORROSION
Torsional Force
LINER
INSERT
PSC

56. WHY GREASING?
CORROSION
End of function life
Rate of
corrosion
Jamming of ERC
Reduction of strength
Loss of Toe Load
End of function Life
Life cycle Time

57. RUBBER PAD
• FUNCTIONS
–
–
–
DAMPING OF HIGH FREQUENCY VIBRATIONS
VIBRATIONALLY ISOLATE RAIL
PREVENT GAP
THE MECHANISM FOR ACHIEVING THIS IS – MOLECULES
BROUGHT CLOSER UNDER FORCE, ENERGY DISSIPATION
WHEN FORCE IS REMOVED.
DAMPING IS BEST WHEN RESTRAINING FORCE IS
PREPORTIONAL TO AMPLITUDE OF VIBRATION.

58. RUBBER PAD
• COMMON TYPE OF PADS
– PIMPLE TYPE PADS
– GROOVED TYPE PADS
• THICKNESS
6 MM

59. LOAD DEFLECTION CHARACTERSTICS
25
SOLID PAD
PRESSURE ON RAIL(T)
20
15
GROOVED PAD
10
5
0
0
10
20
30
40
50
DEFLECTION 1/100 MM
60

60. RUBBER PAD
• MATERIAL
– NATURAL RUBBER
– RIBBED SMOKED SHEET
– BLEND OF STYRENE RUBBER/ POLY
BUTADIENE RUBBER

61. RUBBER PAD
• THE TOP SURFACE OF RUBBER PAD, WHICH
COMES DIRECTLY IN CONTACT WITH RAIL,
EXECUTE VERY HIGH FREQUENCY 1000 Hz (LOW
AMPLITUDE 0.05- 0.1 mm) VIBRATIONS.
• WHILE THE BOTTOM SURFACE, WHICH COMES IN
CONTACT WITH SLEEPER, EXECUTE LOW
FREQUENCY 20 Hz VIBRATIONS.

62. RUBBER PAD
• FOR IMPROVING THE PERFORMANCE OF RUBBER
PAD , MATERIAL SHOULD BE WITH VARYING
ELASTIC PROPERTIES.
• SO THE TOP OF RUBBER PAD SHOULD HAVE HIGHER
MODULUS OF ELASTICITY( HARDER) WHILE
BOTTOM SHOULD BE OF SOFTER MATERIAL.

63. LINERS
– DISTRIBUTION OF TOE LOAD OVER LARGER AREA
ON RAIL FOOT
– ALLOW FLEXIBILITY FOR USE OF DIFFERENT RAIL
SECTION ON THE SAME/ COMMON SLEEPER
– PERMITS GAUGE ADJUSTMENT IN CURVED
TRACK AND CORRECTION IN ALIGNMENT
– PROVIDE INSULATION BETWEEN RAIL AND
INSERT

64. LINERS
• THE REQUIREMENTS OF LINER
– THE LINER SHOULD HAVE PROPER SLOPE TO
MATCH WITH RAIL FOOT SLOPE
– THE VERTICAL LEG OF LINER SHOULD FIT
PROPERLY BETWEEN RAIL AND MCI INSERT TO
MAINTAIN GAUGE
– IT SHOULD BE EASY TO FIX & MANUFACTURE

65. INSERTS
• IT IS EMBEDDED IN CONCRETE AT THE TIME
OF CASTING
• THIS IS ANCHORAGE FOR ERC
• GRIPS THE CLIP EFFECTIVELY
• PROVIDES LATERAL SUPPORT TO RAIL
• SHOULD HAVE ADEQUATE PULL STRENGTH
(MORE THAN 10T)

66. INSERTS
• TOE LOAD IS FUNCTION OF DIA. OF HOLE
AND DIFFERENCE BETWEEN APEX OF HOLE
AND TOP OF SHOULDER
• CORRECT POSITIONING IS IMPORTANT
– VERTICAL POSITIONING FOR TOE LOAD
– LATERAL POSITIONING FOR GAUGE
• THE GAP BETWEEN TOE AND RAIL SEAT
SURFACE SHOULD BE 8 MM.

67. MAINTENANCE OF RAIL JOINTS ON CONCRETE
SLEEPERS
• RAIL JOINTS TO HAVE 1 M. LONG FISHPLATE
• RUBBER PAD OF THE JOINT & SHOULDER
SLEEPERS TO BE RENEWED EVERY YEAR
• CRIB & SHOULDER BALLAST AROUND THE JOINT
TO BE SCREENED EVERY YEAR
• THE FISH PLATE SHOULD BE GROUND TO
ACCOMMODATE ELASTIC RAIL CLIP / PROVIDE JCLIP

68. Thank You