Railway Track Structure & Its components Train Resistances Hauling capacity

1. RAILWAY ENGINEERING
By: Lohit A Havalagi
Assistant Professor, NKOCET Solapur
India

2. BALLAST
CESS
BALLAST CRIB

3. Ballast Crib & Ballast cess
BALLAST CRIB
BALLAST CESS
SLEEPER
RAIL

5. Fishplate & Fish Bolt

7. Level Crossing

8. Points & Crossings

10. Concrete sleeper

11. Cast Iron Sleeper

12. CONONG OF WHEELS

14. Coning of Wheels

15. Tractive Resistances
1. Train Resistance
I. Speed Independent (Rolling) Resistances
II. Speed Dependent Resistances
III. Atmospheric Resistances
2. Resistance due to Track Profile
I. Grade Resistance
II. Curve resistance
3. Resistance due to Starting & accelerating
4. Wind Resistance

16. Track stresses

17. Track stresses

18. Track Modulus
• Load Per Unit Length of the rail Required to
Produce Unit Depression.
• Depends Upon:
1. Gauge
2. Type of Rail section
3. Type of sleeper and density
4. Type of ballast section
5. Subgrade

19. Track stresses
1. Wheel loads
2. Dynamic effect of wheel loads
3. Hammer Blow
4. Lateral Thrust due to Nosing Action
5. Pressure Exerted by the flanges of the wheels
on sides of rails
6. Stresses due to Irregularity of track
7. Additional stresses on curves

20. Hauling Capacity (H.C) &
Tractive Effort (Te)
• Load handled by the locomotive
• H.C is the Product of Coefficient of friction &
Weight on the driving wheels.
Average value of Coefficient of friction= (1/6)

22. Buckling of Track Due to
Temperature stresses

23. Stresses in Rail
• Longitudinal Stresses due to Tractive Effort &
Braking Forces.
• Thermal stresses
• Due irregularity there will be heavy impact on
the rails.
• Minimum Ultimate Tensile Strength of Rail =
72.42 kg/cm2

24. Stresses in the Sleepers
• Stresses in sleepers depends upon:
• Wheel load
• Irregularities in the track
• Speed
• Dynamic effect of wheels on rails
• Elasticity of the rail

25. • Efficiency of Fastenings
• Design & Dimension of Sleeper
• Strength of Sleeper
• Track Modulus
• Stiffness of the rail
• Maintenance of track

26. Stresses in the Ballast
Stresses in Ballast depends on:
• Elastic Property of the sleeper
• Degree of compaction
• Nature of Ballast bed
• Bigger the cess & size of sleeper, lesser the
Pressure in ballast & formation.

27. Stresses in the Formation
• Stresses in subgrade is decreased by
increasing both depth & Size of the Ballast.
• Quality & Gradation of Ballast influences
ultimate pressure on formation.