Draft forces are?

Draft forces are?

• A. A term used to describe tension coupler forces that stretch the slack in a train.
• B. The aerodynamic drag on the train.
• C. The friction between rails and wheels.
• D. A term used to describe compressive coupler forces in a train.

Answer: (A)

Draft forces are the pulling, tensile forces transmitted through the train’s couplers when the locomotive (or leading car) pulls the train. As tractive effort is applied, these couplers stretch the slack between cars, taking up the small gaps so the entire train can start moving as one unit. This tension is what we call draft force. It differs from aerodynamic drag (air resistance) and wheel-rail friction (rolling resistance), and it is not about compression or pushing forces.

Draft forces are the pulling, tensile forces transmitted through the train’s couplers when the locomotive (or leading car) pulls the train. As tractive effort is applied, these couplers stretch the slack between cars, taking up the small gaps so the entire train can start moving as one unit. This tension is what we call draft force. It differs from aerodynamic drag (air resistance) and wheel-rail friction (rolling resistance), and it is not about compression or pushing forces.