# Railway Engineering Questions and Answers – Requirements of a Good Ballast and Design of Ballast Section

This set of Railway Engineering MCQs focuses on “Requirements of a Good Ballast and Design of Ballast Section”.

1. The pressure distribution in the ballast section does not depend on which of the following factors?
a) Shape of ballast
b) Size of ballast
c) Cant of track
d) Degree of consolidation

Explanation: Load is transferred from sleeper to formation through ballast. The pressure distribution depends upon the degree of consolidation, size and shape of ballast.

2. Which of the following is the correct formula for calculating the depth of ballast cushion?
a) Sleeper spacing = width of the sleeper + 3 × depth of ballast
b) Sleeper spacing = width of the sleeper + depth of ballast
c) Sleeper spacing = width of the sleeper + 2 × depth of ballast
d) Sleeper spacing = 3 x width of the sleeper + 2 × depth of ballast

Explanation: The depth of the ballast cushion can be calculated by using the sleeper spacing and width of sleeper. Sleeper spacing = width of the sleeper + 2 × depth of ballast.

3. What is the shape of the pressure lines formed due to the dispersion of load in the ballast?
a) Bulb shaped
b) Straight lines
c) Parabola
d) Triangular

Explanation: The lines of same pressure are bulb shaped. But for convenience we take the load dispersion at an angle of 45° to the vertical.

4. Dwarf walls should be provided in case of cuttings.
a) True
b) False

Explanation: Dwarf walls of suitable properties are provided in case of cuttings. This is to protect or retain the ballast in case when speed of the locomotive is very high.

5. Which of the following is not a requirement of a good ballast?
a) Tough
b) Wear resistant
c) Rounded
d) Cheap

Explanation: Ballast should not be rounded. It should generally be cubical having sharp edges. This is regarding the shear strength provided by the Ballast.

6. Why should the ballast be hard?
a) So that it does not get crushed
b) So that it can absorb water
c) To allow good drainage
d) To keep it cheap

Explanation: A locomotive transfers all the load from its wheels rails and sleepers which in turn transfer it to the Ballast. Thus the ballast needs to be hard to bear this load and mitigate the risk of crushing because of it.

Sanfoundry Global Education & Learning Series – Railway Engineering.