Consider the following statements related to economic design of modern track: 1.Axle loading, possible weight reduction of the rolling stock and increase in number of axles should be rationalized. 2.Rail to sleeper fastenings for different type of sleepers at high speeds should have definite standards. 3.The weight of the sleeper and the rail may not be related to each other. Which of the above statements are correct?
- A1 and 2 onlyCorrect
- B2 and 3 only
- C1 and 3 only
- D1, 2 and 3
Solution
Concept
In economic track design, axle load, fastenings, rail and sleeper must be planned together as one system.
Step-by-step solution
1. Statement 1: Rationalizing axle load, the weight of rolling stock and the number of axles is part of economic track design, so it is correct. 2. Statement 2: Fastenings for different sleepers at high speed need definite standards, so it is correct. 3. Statement 3: The weight of the sleeper must be related to the weight of the rail for a balanced track, so it is wrong. 4. Correct statements are 1 and 2 only.
Explanation
A modern track works as one system. Rail weight, sleeper weight, fastenings and axle loads must all match each other. So the claim that sleeper and rail weight may not be related is wrong.
Why the other options are wrong
B and C include statement 3, which is wrong. D includes all three statements, but statement 3 is wrong.
Shortcut
In track design, components are always related, so reject any statement that says they 'may not be related'.
Common mistake
Thinking the rail and sleeper can be chosen independently of each other.
Correct answer: A) 1 and 2 only