Why are railway tracks laid on large sized concrete sleepers?
(a) When the train passes over a railway track, the whole weight of the train acts on the railway line beneath it. Due to large sized concrete sleepers, the force of this weight spreads out over a large area, thereby reducing the pressure on the ground. As a result, the railway track can bear it.
Why are iron rails of railway track fixed over wide wooden or concrete sleepers Class 8?
Explanation: Wooden or concrete sleepers are fixed over a wide region to spread out the load due to the moving train. The wider the area, the less the pressure exerted. In the absence of the sleepers, the rails would sink into the ground due to the heavy load of the moving train.
Why are wooden sleepers kept below the railway line?
We know that Concrete or wooden sleepers are kept below the railway line so that the weight of passing trains is spread over a large area of ground and the track may not sink into the ground. Therefore the pressure acting on the ground under the sleepers is reduced.
Why are wooden slippers kept below railway?
Railway tracks are laid on large sized wooden sleepers so that the thrust due to the weight of train is spread over large area . This reduces the pressure on the ground which would prevent the yielding of the ground.
Why do train tracks have wooden planks?
The crushed stones are what is known as ballast. Their purpose is to hold the wooden cross ties in place, which in turn hold the rails in place. The answer is to start with the bare ground, and then build up a foundation to raise the track high enough so it won’t get flooded.
What is laid down below the railway lines to distribute the pressure of train?
Sleepers are laid below the rails so that the weight of passing train is spread over a large area (which decreases pressure) and the track may not sink into the ground.
Why the railway tracks are placed on broad wooden or concrete wedges?
Railway tracks are laid on wooden sleepers so as to spread the surface area of contact, such that if a train moves over the rails, the railway are not damaged. Increase in area = Increase in denominator = Decrease in final value.
What are the function of sleepers?
(i) The primary function of a sleeper is to grip the rail to gauge and to distribute the rail loads to ballast with acceptable induced pressure. (ii) The side functions of a sleeper include the avoidance of both longitudinal and lateral track movement.
What is the function of a fish plate?
Functions of Fish Plates are : a) To join the rail ends to maintain the line and level of the top table and gauge face of the rail ends and to resist the impact and prevent the deflection of the rail joint with the help of closely spaced sleeper support. b) To transfer the load of the wheels from one rail to the other.
Which of the following is not used to fix the rail to sleepers?
2. Two way keys are not used for fixing which of the following sleepers? Explanation: Two way key has a two way taper provided at both the ends and it can be driven in both the direction. It is used for fixing CST-9, Pot and Trough sleepers.
What must be done to wooden sleepers before use?
Explanation: The wood for the sleepers is taken directly from the trees and they contain moisture. In order to reduce the moisture content, seasoning is adopted. In India, air seasoning is the most commonly used method.
What is used for fixing the rails to the wooden sleeper?
Bearing plates are used for fixing wooden sleepers to rails.
What is coning of wheel?
Coning of Wheel The rim or flanges of the wheels are never made flat but they are in the shape of a cone with a slope of about 1 to 20. This is known as coning of wheels. The coning of wheels is manly done to maintain the vehicle in the central position with respect to the track.
What are the disadvantages of coning of wheel?
Disadvantages of Coning of Wheel
- The pressure on the horizontal component of force near the inner edge of outer rail has a tendency to wear the rail quickly.
- The horizontal component has to turn the rail outwards and hence the gauge may be widened.
What is the drawback of bull headed rails?
What is a drawback of Bull headed rails? Explanation: Bull headed rails can better withstand wear and tear and thus have long lives. But they require a chair so that they can be fixed with sleepers.
What would be the result without coning of wheels?
Explanation: Without coning of wheels the flat wheels might slip on the tracks during traversing a curve. This would lead to contact of flange and rail track. This would lead to uncomfortable journey.
What is the value of coning of wheels?
Purpose: To keep the train in its central position of the rails, coning does not allow any sidewise movement on a straight track. to allow the wheels to move different distances on a curved track and thereby reduce wear and tear.
Which type of railway sleepers have the best service life?
Concrete sleepers have many advantages like longer lifespan, high stability, small maintenance, low damage rate and low scrap rate. They are widely used in high speed railway and the stability is much higher than wood sleepers.
Which is statement is correct for coning of wheels?
Explanation:
| A. | The coning of wheels is provided for smooth running of trains. | The coning of wheel prevents the wear of the inner faces of rails |
|---|---|---|
| C. | If the axle moves laterally towards one rail, the diameter of wheel rim increases on that rail | On curves, the outer wheel has to travel lesser distance than the inner wheel. |
Why coning of wheel is provided?
The coning of wheels is provided to keep the vehicle in the central position with respect to the track and helps the vehicle to move smoothly on the straight and curved track. Also, due to the action of centrifugal force on a curve, the vehicle has a tendency to move out towards the outer rail.