What should be done before detaching the locomotive after a pickup?

Before detaching the locomotive after a pickup, closing the angle cock on the rear of the locomotive while leaving it open on the cars is an important step in ensuring the safety and proper functioning of the train. The angle cock is a critical component in the air brake system; it controls the flow of air between the locomotive and the cars. By closing the angle cock on the locomotive, you prevent air from escaping and maintain the necessary pressure for the air brakes on the cars that are being left standing. This action helps to prevent any potential loss of brake effectiveness which is essential for maintaining safety on the track after the locomotive is detached.

Moreover, keeping the angle cock on the cars open allows them to remain in a state where they can be properly braked if necessary. This practice is vital for maintaining control over the standing cars, ensuring that they do not roll away or cause an accident after the locomotive has been removed.

Therefore, this procedure contributes to overall operational safety and efficiency in train handling.