If PTC and Cabs fail in 562 territory with a "Clear to the next block" signal, what is the speed limit?

In the scenario described, when both PTC (Positive Train Control) and Cabs (Cab Signaling systems) fail in a territory where a "Clear to the next block" signal is displayed, the applicable speed limit is typically classified as "Restricted speed."

Restricted speed is defined as the speed at which a train must be able to stop within one half the range of vision or within a specified distance, ensuring safety under conditions where signals or onboard systems have failed. This speed is essential to maintain control and safety, particularly in territories governed by specific signaling rules.

The "Clear to the next block" indication implies that the segment of track ahead is clear, but given the failure of both critical signaling systems, the train must adhere to the more cautious restricted speed rather than any higher operational speeds. This is to minimize risk and ensure adequate response time for unforeseen obstacles or track conditions that might not be immediately visible.

Therefore, the determination of restricted speed as the appropriate limit under these conditions reflects the necessity of maintaining a conservative approach to train operation in the event of signaling system failures.