How should a train proceed after receiving a Form D line 13 along with a cab signal failure?

The appropriate course of action for a train after receiving a Form D line 13 along with a cab signal failure is to proceed according to Rule 563. This rule provides specific guidelines for operating in situations where there is a lack of cab signal control due to malfunction or failure.

Under Rule 563, the train must operate at a restricted speed until the situation is resolved, which allows for safer navigation since the cab signals are non-functional. The rule is designed to ensure that the train crew can react to any unexpected conditions or obstacles ahead while maintaining safety on the tracks.

Choosing options like proceeding at maximum speed or relying solely on fixed signal indications would compromise safety and go against established protocols for handling a cab signal failure. Hence, following Rule 563 ensures that the train can navigate the tracks safely, considering the limitations imposed by the cab signal failure.