When does an engineer move by absolute block?

An engineer moves by absolute block when there is no automatic train stop or dead man protection in the head car. This scenario indicates a situation where additional safety measures are not in place to prevent overspeeding or unintended movement of the train. In such cases, the engineer must operate under strict rules to maintain safe distances and ensure that the train does not enter an occupied block.

Using absolute block means that train movements are restricted to ensure safety, especially when automated systems that typically help manage train speed and stopping are absent. This precaution is critical for maintaining safety on the tracks, as it necessitates continuous manual control and attention from the engineer. It effectively enhances safety protocols during potentially hazardous situations where automatic systems would typically assist in preventing accidents.

The other scenarios provided do not necessarily imply the need for absolute block procedures as they may not involve the same level of risk or safety concerns associated with operating without automatic safety systems.