Draft forces are present when a train is in which condition?

Draft forces are significant when a train is in a slack-stretched condition. In this scenario, the couplers between the railcars are pulled tight, leading to the carriage of traction force along the train. This condition arises when the locomotive is applying power to move forward, causing a tension in the train’s couplers, which translates to a pulling force that is referred to as draft.

When the train is in slack-stretched condition, the draft forces effectively help to maintain control over the train's movement, ensuring a smoother operation as the tension created assists in transferring the pulling force from the front of the train to the rest of the railcars. Understanding the dynamics of draft forces is vital for operational safety and efficiency, especially during acceleration and on inclines.