The Reason Trains Carry Fuel They'll Never Actually Use

Freight locomotives depart with fuel loads that exceed what any reasonable route calculation requires — and the excess isn't waste planning. It's operational insurance against a specific category of railroad contingency that dispatchers and engineers know is always possible: rerouting. When a mainline is blocked by a derailment, a crossing accident, or track maintenance, a locomotive can be redirected over a longer alternate route that might add hundreds of miles to its journey without warning. A locomotive that left with precisely calculated fuel for its intended route can't handle that rerouting without stopping for fuel — and stopping for fuel on an unplanned diversion creates cascading delays that cost the railroad more than the extra fuel weight it carried as contingency from the origin.