What is the maximum number of air brake devices that can be cut out together in a train?

The correct answer is two, which reflects the regulations that govern the operation of air brake systems on trains. According to safety standards, if too many air brake devices are cut out, it could jeopardize the train's overall braking capacity and increase the risk of accidents. By allowing only two air brake devices to be cut out simultaneously, safety is preserved while still providing the flexibility to manage minor issues with the train's braking system. This limit ensures that there remains adequate braking power to control the train effectively, particularly in emergency situations. Therefore, maintaining a balance between operational flexibility and safety is essential, and this particular guideline reflects that balance in practice.