What three methods are used to determine the air pressure at the rear of a train?

The correct answer involves three methods that provide an accurate assessment of air pressure at the rear of a train. Using an accurate gauge is essential, as it directly measures the air pressure within the brake line. This allows for immediate and reliable feedback on the braking system's status.

The End-of-Train (E.O.T.) device plays a critical role as well, as it is equipped with sensors that monitor the pressure in the brake line and transmit this information back to the locomotive. This communication ensures that the engineer is aware of the conditions at the rear of the train, which might differ from those at the front due to potential pressure loss or leaks.

Finally, having a distributed power locomotive expands the control and monitoring capabilities of the train. These locomotives help manage the air brakes more effectively throughout the train by providing additional data and control from locations between the front and rear of the train.

Together, these three methods ensure a comprehensive understanding of air pressure at the rear, thus enhancing the safety and efficiency of train operations.