Question

The Cant deficiency for a $5^{\circ }$ curve of B.G track is _________ cm (upto two decimal places).

• A. 4.6

Answer 1

The correct option is A 4.6
Given, $D=5^{\circ }$

Radius, R = $\frac{1750}{D}=\frac{1750}{5}=350m$

From Martin's formula

$V_{max}=4.35\sqrt{R-67}$ (assuming $V_{max}<100kmph$

$V_{max}=4.35\times \sqrt{350-67}=73.18kmph$

Theoretical cant required,

$e_{th}=\frac{G{V}^2}{127R}=\frac{1.75\times {73.18}^2}{127\times 350}=0.211m=21.1cm$

and for speed < 120 kmph
$e_{max}=16.5cm$

Hence, cant deficiency = 21.1 - 16.5

= 4.6 cm