Under what condition can a train operator key-by a signal with an AK sign displayed?

Under what condition can a train operator key-by a signal with an AK sign displayed?

• A. When the signal is malfunctioning
• B. When given authority from RCC
• C. Only at night
• D. When the signal shows green

Answer: (B)

The correct answer is based on the understanding that an operator can only key-by a signal with an AK sign when they have received explicit authority from the Rail Control Center (RCC). The purpose of the AK sign is to indicate that the signal is displaying a restriction, and it is not automatically safe to proceed without proper authorization. The RCC is responsible for overseeing train operations and ensuring safety protocols are followed. By requiring authority from the RCC, it ensures that the operator is fully informed of any necessary precautions or restrictions in place, thus maintaining safety and proper operation despite the signal's indication. Regarding the other options, while a malfunctioning signal may lead to special operating procedures, it does not automatically permit keying by without authorization. Keying by only at night does not reflect any standard operating procedure, as the ability to proceed past an AK sign is not limited to specific times. Finally, a green signal typically indicates that it is safe to proceed without restrictions, thereby negating the need for keying by.

The correct answer is based on the understanding that an operator can only key-by a signal with an AK sign when they have received explicit authority from the Rail Control Center (RCC). The purpose of the AK sign is to indicate that the signal is displaying a restriction, and it is not automatically safe to proceed without proper authorization. The RCC is responsible for overseeing train operations and ensuring safety protocols are followed. By requiring authority from the RCC, it ensures that the operator is fully informed of any necessary precautions or restrictions in place, thus maintaining safety and proper operation despite the signal's indication.

Regarding the other options, while a malfunctioning signal may lead to special operating procedures, it does not automatically permit keying by without authorization. Keying by only at night does not reflect any standard operating procedure, as the ability to proceed past an AK sign is not limited to specific times. Finally, a green signal typically indicates that it is safe to proceed without restrictions, thereby negating the need for keying by.