For reference only — not a substitute for professional engineering judgement. See Terms.
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Track gauge: — mm · Rail head width: — mm
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Formula reference
Cant factor (depends on gauge and rail head width):
cf = (G + w) / (g × 3.6²) where g = 9.81 m/s²
Equilibrium speed:
Veq = √(e × R / cf) (km/h; e in mm, R in m)
Equilibrium cant:
eeq = cf × V² / R (mm; ≈ 8.9 × V² / R for standard gauge)
Cant deficiency / excess:
D = eeq − e (deficiency if +ve, excess if −ve)
Cant rate (1 in n):
n = L × 1000 / e (L in m, e in mm)
Rate of change of cant:
dc/dt = e × V / (3.6 × L) (mm/s)