When approaching turnouts with the train's air brakes released, how should dynamic brake retarding force be limited?

Limiting the dynamic brake retarding force to 50 percent of maximum dynamic brake effort is important for several reasons. When a train is approaching turnouts with the air brakes released, it is critical to manage the speed and the forces acting on the train to maintain control and ensure safety.

Dynamic braking works by utilizing the traction motors of the locomotive to slow down the train, but applying too much dynamic braking too quickly can lead to wheel slip, instability, and loss of control. By restricting the dynamic brake force to 50 percent of maximum effort, it allows for a smoother reduction in speed while providing adequate retarding force to keep the train under control as it approaches the turnout. This approach minimizes the risk of over-stressing the train's components and helps prevent derailment or other incidents associated with excessive braking force.

Overall, managing dynamic brake effort effectively helps to ensure that the train navigates turnouts safely and maintains operational integrity.