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Length of Transition Curve based on Rate of change of Super Elevation Calculator

Transition Curve Length Formula:

\[ LSE = 0.073 \times e_{Vmax} \times V_{max} \times 100 \]

m
km/h
%

1. What is a Transition Curve Length Calculator?

Definition: This calculator estimates the length of transition curve needed based on equilibrium cant and maximum train speed, including a tolerance factor.

Purpose: It helps railway engineers design smooth transitions between straight and curved tracks for passenger comfort and safety.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ LSE = 0.073 \times e_{Vmax} \times V_{max} \times 100 \]

Where:

  • \( LSE \) — Length of transition curve (meters)
  • \( e_{Vmax} \) — Equilibrium cant for maximum speed (meters)
  • \( V_{max} \) — Maximum speed of train on curve (km/h)

Explanation: The formula calculates the minimum length required for a smooth transition based on speed and cant, with an optional tolerance percentage.

3. Importance of Transition Curve Calculation

Details: Proper transition curves ensure gradual introduction of centrifugal force, preventing sudden lateral forces that could derail trains or discomfort passengers.

4. Using the Calculator

Tips: Enter the equilibrium cant (typically 0.05-0.15m), maximum train speed, and tolerance percentage (default 5%). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is equilibrium cant?
A: The difference in height between outer and inner rails needed to counteract centrifugal force at maximum speed.

Q2: Why include a tolerance factor?
A: The ±5% tolerance accounts for variations in construction and operational conditions.

Q3: What's a typical maximum speed?
A: Varies by line class - from 50 km/h for freight lines to 300+ km/h for high-speed rail.

Q4: How does cant affect curve length?
A: Greater cant requires longer transition curves to maintain comfortable rate of change.

Q5: Can this be used for highway curves?
A: No, highway transition curves use different formulas based on vehicle dynamics.

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