What maximum speed must an MU train operate at if the ASC warning device fails?

When the Automatic Speed Control (ASC) warning device fails on an MU train, it is crucial to follow established safety protocols to ensure the safety of passengers and crew. The maximum speed limit in the event of an ASC failure is set at 30 mph. This speed limit is implemented to reduce the risk of accidents, as the ASC system is responsible for regulating the train's speed and ensuring safe operations under normal conditions.

Operating at this reduced speed allows the operator to have better control of the train, making it easier to respond to potential hazards or signals on the tracks. As trains can encounter various situations such as track curves, signals, and other trains, maintaining a more conservative speed helps ensure the safety of the operation until the ASC system can be repaired or the train can be taken out of service for further inspection.

By adhering to the maximum speed of 30 mph under these circumstances, the operator is minimizing risks and promoting safe train operations in compliance with the LIRR rules and regulations.