Example: Total Train Resistance
Example
Problem Statement:
A freight train with a total gross weight of 5,000 tons is traveling at a constant speed of 40 mph up a 1.5% grade on a 2-degree curve.
Using the simplified Davis Equation, the rolling resistance () for this specific train at 40 mph is estimated to be 4 lbs per ton.
Calculate the total resistance () that the locomotives must overcome to maintain this speed.
Solution: Train Resistance Calculation
0 of 4 Steps Completed1
Example: Grade Resistance Calculation
Trains are extremely sensitive to longitudinal grades due to their mass and low steel-on-steel friction.
Example
Problem Statement:
A freight train has a total mass of 10,000 tons. It is ascending a 1.5% grade. Calculate the grade resistance acting against the train in pounds.
Given:
- Train weight () = 10,000 tons
- Grade () = 1.5%
Step-by-Step Solution
0 of 2 Steps Completed1
Example: Ruling Grade Capacity
The ruling grade dictates the maximum tonnage a single locomotive can pull.
Example
Problem Statement:
A locomotive has a maximum tractive effort (pulling force) of 150,000 lbs. The rolling resistance on level track is assumed to be 5 lbs/ton. The ruling grade on the subdivision is 1.0%. What is the maximum train weight (in tons) this locomotive can pull up the ruling grade?
Given:
- Tractive Effort () = 150,000 lbs
- Rolling Resistance = 5 lbs/ton
- Ruling Grade () = 1.0%
Step-by-Step Solution
0 of 2 Steps Completed1