The design speed for a two-way traffic on a two way lane road is 50
kmph. What is
the value of safe stopping sight distance, if co-efficient of friction
is 0.37 and reaction
time of driver as 2.5 sec?
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?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
(A)
A modern track has to be rationalized in view of the following to achieve over-all economy
on Indian Railways.
i. Rail requirements, like quality of steel, design of rail-section and manufacturing
process, should be rationalized so that the rail section can sustain the expected
stresses due to rolling loads.
ii. Wheel diameter in relation to qualities of rail steel and steel of the wheel tyre should
also be rationalized so as to keep Hertzian stresses within the endurance limits of
the steel.
iii. Axle loading, possible weight reduction of the rolling stock and increase in number
of axles should be rationalized.
iv. Rail-to-sleeper fastenings i.e., elastic fastenings for different types of sleepers at
high speeds should have definite standards.
v. The weight of the sleeper and the rail should be correctly related to each other
