TRL & Maximum Speed Calculation for 1.458° Curveature 1200 m.
Radius
Curve No. 1 Maximum sectional Speed = 50 KMPH
Limiting Value of Ca = 165 mm Gr.A,B,C
R= 1200 m ( 1.458 °) Limiting Value of Cd = 75 mm
Proposed Cant = 20 mm
A) GV
2
1750 x 50 ^2
Ca + Cd = = = 28.7 mm.
127R 127 x 1200
Cant deficiency Cd calculated = 28.7 - 20 = 9 mm. < 75mm. O.K.
B) Cant Excess Consideration
Considering speed of Goods Train = 50 Km. Per Hour
2
GV 1750 x 50 ^2
Ca + Cd = = = 28.7 mm.
127R 127 x 1200.000
Cant Excess = 20 - 28.7 = -8.7 mm. < 75 mm. O.K.
C) Maximum sectional Speed based on Ca & Cd (assume above)
Vmax = 0.27 x 1200.000 x( 20 + 9 )
= 50 Kmph Say 50 Kmph (Max. Permissible Speed)
Desirable Transition Length = Maximum of the following: -
(i) L = 0.0056 Ca x Vmax = 0.0056 x 20 x 50 = 5.6 m.
(ii) L = 0.0056 Cd x Vmax = 0.0056 x 9 x 50 = 2.4 m.
(iii) L = 0.72 x Ca = 0.720 x 20 = 14.4 m.
Desirable Transition Curve Length (Maxm. from the Equn. (i) - (iii) = 5.6 m
Length of Transition Curve Provided as = 90 m hence OK
Cant Gradient = (Ca / Trl. X 1000)= 1 in 4500 > 1 in 720 , hence OK
PROP. SE = 20 mm.
PROP.TRL = 90 Mtr.
PERMISSIBLE SPEED = 50 KMPH