Q.1 For a railway track, the width of the formation depends upon which of the following? i. Type of sleepers ii. Type of ballast iii. Type of gauge iv. Number of tracks, i.e. single or double track
- ABoth iii and ivCorrect
- BBoth i and iv
- CBoth i and ii
- DBoth ii and iii
Solution
Concept
Formation width of a railway track depends mainly on the gauge and the number of tracks.
Step-by-step solution
1. Formation is the levelled bed (embankment top or cutting bottom) on which ballast and track are laid. 2. A wider gauge needs longer sleepers and a wider ballast section, so it needs a wider formation. 3. A double track needs about one extra track width plus the track spacing, so it needs a much wider formation. 4. So formation width depends on the type of gauge (iii) and the number of tracks (iv). 5. Answer is (A).
Explanation
Formation width is decided mainly by the gauge (BG, MG or NG) and by whether the line is single or double. Wider gauge and more tracks need a wider formation. Standard railway tables give formation width by gauge and number of tracks.
Why the other options are wrong
B: sleeper type is not the main deciding factor, and it misses gauge. C: sleeper and ballast type do not mainly decide formation width. D: ballast type is not the main factor, and it misses number of tracks.
Shortcut
Formation width = Gauge + Number of tracks.
Common mistake
Choosing ballast or sleeper type because they lie on the formation. The width is still set mainly by gauge and number of tracks.
Correct answer: A) Both iii and iv