What is the signal series in Tunnel B going uptown?

The signal series in a tunnel system varies based on operational protocols and local regulations concerning train signaling. In your question regarding the signal series for Tunnel B going uptown, the series defined as 100 odd indicates a specific classification of signals that are utilized for controlling train movements in that segment of the track.

In many rail systems, odd-numbered signals are typically used to indicate certain aspects of train operations, such as clearances or restrictions. The choice of the 100 series is often used for its distinctiveness, as it helps train operators quickly identify the signal status while ensuring standardization across the rail network. This level of specificity is crucial for maintaining safety and efficiency within the system.

The other options may represent different signal series that could apply to other scenarios or sections of the rail system but do not specifically relate to Tunnel B's uptown signals as outlined in the question. The adoption of the 100 odd series suggests that it is designed for clarity and alignment with operational standards for that particular segment of the railway infrastructure.