What is the maximum speed allowed when running on clear signals in under river tubes?

The maximum speed allowed when running on clear signals in under river tubes is 35 MPH. This speed limit is established to ensure safety and operational efficiency within the confines of the tube environment, where certain conditions can restrict visibility and the ability to respond to emergencies.

Running at this speed allows for adequate reaction time in the event of unforeseen circumstances, such as track obstructions or equipment failures. Additionally, the design and engineering of the under river tube may impose limitations that are consistent with maintaining the structural integrity of the infrastructure while ensuring passenger safety.

This specific limit contrasts with higher speeds, which may introduce risks that are not manageable in the confined spaces of underground systems. Hence, the choice of 35 MPH reflects a balanced approach to safety while allowing for the efficient operation of trains under normal conditions in under river tubes.