Why is it important to check angle cocks after adding cars to a train?

Checking angle cocks after adding cars to a train is crucial primarily to prevent any leaks in the brake system. Angle cocks are valves located at each end of a railcar that control the flow of air in the braking system. If these valves are not properly closed or if there is an issue with their sealing after adding new cars, it can lead to air leaks.

Air leaks can significantly impair the functionality of the train's braking system, which relies on a pressurized air supply to operate effectively. A compromised braking system can result in insufficient braking power, potentially leading to dangerous situations while the train is in operation. Therefore, ensuring that angle cocks are checked and functioning correctly is part of maintaining a safe and reliable train operation, directly linked to the integrity of the brake system.

While correct airflow, train stability, and communication between cars are important factors in train operation, the immediate priority when checking angle cocks pertains to the integrity and effectiveness of the braking system.