Which of the following is the correct holding test time for a 400 meter train?

The correct holding test time for a 400 meter train is 20 minutes. This duration is established based on the safety protocols and operational requirements necessary for ensuring that the train is properly assessed for conditions that may affect its performance or safety during a hold.

In the context of rail operations, holding tests are critical for verifying that trains are functioning as expected, particularly with regard to their braking systems and other safety mechanisms. A 20-minute holding period allows sufficient time to conduct comprehensive checks and ensure that any potential issues are identified and addressed before the train resumes its journey.

Longer or shorter holding times would not provide the same level of assurance regarding the train’s readiness or could potentially lead to delays and complications in operational schedules. This adherence to the 20-minute standard reflects established best practices within the industry, which prioritize safety and efficiency.