How Does a 3-Mile Train Start Moving Without Snapping?
A 3-mile freight train weighs more than 15,000 tons. The coupler holding the front car to the lead locomotive snaps at around 390,000 pounds of pull. Pulling 15,000 tons from a dead stop should rip that first car loose before the rear of the train ever moves an inch. How does this happen every day across North America without trains tearing themselves in half? Why doesn't the front car shear off the moment the throttle opens? What is the engineer doing that the math seems to forbid?