Question

The safe speed on transition curve of B.G. track can be calculated by using formula :
1. \(4.35 \sqrt{(R-67)}\)
2. \(4.4 \times\sqrt{(R-67)}\)
3. \(3.65 \times \sqrt{(R-6)}\)
4. None of the above

Answer 1

Correct Answer - Option 1 : \(4.35 \sqrt{(R-67)}\)

Concept:

As per martin’s formula, safe speed can be given as follow:

a) For low speed (< 100 kmph)

(i) On a transition Curve:

Depending on the radius of the curve (in meter) and the speed for transition curves can be given by Martin’s Formula,

For Broad Gauge and Meter Gauge:

The safe speed on the transition curve

\({V_s} = 4.35\sqrt {R - 67} \) km/hr

or

\({V_s} = 4.4\sqrt {R - 70} \)

For Narrow Gauge:

The safe speed on the transition curve

\({V_s} = 3.65\sqrt {R - 6} \) km/hr

Subjected to a maximum of 50 kmph.

(ii) On a non-transitional curve: 80% of the above-given speeds for respective gauges.

b) For High speed (> 100 kmph)

\({\rm{V}} = 4.58\sqrt R\) kmph