Tractive Effort Required During Free-Running Calculator

Free Run Tractive Effort Formula:

\[ F_{free} = (98.1 \times W \times G) + (W \times R_{sp}) \]

Free Run Tractive Effort:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Free Run Tractive Effort?

Free Run Tractive Effort refers to the pulling or pushing force that a vehicle or locomotive needs to overcome resistance and move forward. It is the force required to maintain motion against various resistances including gradient resistance and specific train resistance.

2. How Does the Calculator Work?

The calculator uses the Free Run Tractive Effort formula:

\[ F_{free} = (98.1 \times W \times G) + (W \times R_{sp}) \]

Where:

\( F_{free} \) — Free Run Tractive Effort (N)
\( W \) — Weight of Train (tonns)
\( G \) — Gradient (%)
\( R_{sp} \) — Specific Resistance Train (N/tonn)

Explanation: The equation calculates the total force required to overcome both gradient resistance (98.1×W×G) and specific train resistance (W×Rsp).

3. Importance of Tractive Effort Calculation

Details: Accurate tractive effort calculation is crucial for locomotive design, train operation planning, and ensuring efficient and safe railway operations. It helps determine the required locomotive power for specific train configurations and route conditions.

4. Using the Calculator

Tips: Enter train weight in tonns, gradient in percentage, and specific resistance in N/tonn. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect specific resistance train?
A: Specific resistance arises from various factors including vehicle design, track conditions, curvature, air resistance, and other environmental conditions.

Q2: Why is 98.1 used in the gradient component?
A: The constant 98.1 represents the product of gravitational acceleration (9.81 m/s²) and the conversion factor for percentage gradient.

Q3: How does gradient affect tractive effort?
A: Higher gradients require significantly more tractive effort as the locomotive must overcome the gravitational force component acting against the train's motion.

Q4: What are typical values for specific resistance?
A: Specific resistance values vary widely depending on train type, speed, and conditions, typically ranging from 5-15 N/tonn for freight trains.

Q5: Can this formula be used for all train types?
A: While the basic principle applies to all trains, specific resistance values may need adjustment for different train configurations and operating conditions.