Which of the following factors affect the selection of radius of a curve on a railway track?

Which of the following factors affect the selection of radius of a curve on a railway track?

The key parameters to determine the minimum curve radius of the railway are superelevation cant, unbalanced lateral acceleration, and other parameters; the determination of these parameters is influenced by complex factors such as the performance of high-speed train and track structure.

When a train travels around a curve at a speed lower than the equilibrium speed is known as?

(4) Cant excess – Cant excess occurs when a train travels around a curve at a speed lower than the equilibrium speed. It is the difference between the actual cant and the theoretical cant required for such a lower speed.

What are factors affecting minimum radius of curvature?

Minimum curve radius can be determined to take into account superelevation, lateral acceleration, sight distance and lateral Jerk.

How do trains go around bends?

When a train with slanted wheels turns, centrifugal force pushes the outside wheel to the larger part of the cone and pushes the inside wheel to the smaller part of the cone. As a result when a train is turning it is momentarily running on wheels that are effectively two different sizes.

What is the radius of a one degree curve?

As an example, a curve with an arc length of 600 units that has an overall sweep of 6 degrees is a 1-degree curve: For every 100 feet of arc, the bearing changes by 1 degree. The radius of such a curve is 5729.57795.

What type of curve is used for railway?

A track transition curve, or spiral easement, is a mathematically-calculated curve on a section of highway, or railroad track, in which a straight section changes into a curve. It is designed to prevent sudden changes in lateral (or centripetal) acceleration.

What is responsible for the cant deficiency in a vehicle when it moves around a curve?

Cant deficiency is present when a vehicle’s speed on a curve is greater than the speed at which the components of wheel to rail force are normal to the plane of the track. In order to reduce cant deficiency, the speed can be reduced or the superelevation can be increased.

What is the maximum superelevation provided in BG?

The maximum value of the superelevation generally adopted around many railways around the world is 1/10th to 1/12th of the gauge. The values of maximum superelevation prescribed on Indian Railways are given in Table 13.2.

What is the minimum radius of curvature?

The minimum curve radius is a limiting value of curvature for a given design speed. In the design of horizontal alignment, smaller than the calculated boundary value of minimum curve radius cannot be used. Thus, the minimum radius of curvature is a significant value in alignment design.

What happens to a train on a superelevated curve?

Since a train traversing a heavily superelevated curve at a relatively slow speed tends to cause excessive wear on the low rail, many railroads reduced curve superelevation when their passenger trains disappeared. This practice has worked against the reinstatement or speeding up of passenger service.

How is the speed of a train determined on curves?

As per the procedure being followed at present, the determination of the maximum permissible speed on curves without transitions involves the concept of virtual transitions. The linear velocity of a train moving with uniform velocity on a straight track begins to change into angular velocity as soon as the first bogie reaches the tangent point.

What is the effect of grades on trains?

The effect of grades on train operations is significant. For each percent of ascending grade, there is an additional resistance to constant-speed movement of 20 lbs. per ton of train. This compares with a resistance on level, straight track of about 5 lbs. per ton of train.

Which is the best example of speed on a curve?

Example 13.1 Calculate the superelevation and the maximum permissible speed for a 2 o BG transitioned curve on a high-speed route with a maximum sanctioned speed of 110 km/h. The speed for calculating the equilibrium superelevation as decided by the chief engineer is 80 km/h and the booked speed of goods trains is 50 km/h.