Which types of signals must locomotive engineers understand?

Locomotive engineers must have a thorough understanding of block signals and interlockings as both are crucial for safe train operations. Block signals indicate whether a section of track is clear or occupied, helping engineers manage the spacing and movement of trains to prevent collisions. Understanding how these signals operate allows engineers to make informed decisions while navigating the railway.

Interlockings are critical components of railway signaling systems that control train movements through junctions and crossings. They ensure that conflicting train paths are managed safely, thereby preventing accidents. By comprehending how interlockings function and their relationship to block signals, locomotive engineers can optimize their responses while operating a train in various conditions.

The other options include signals that may not be formal elements of railway training or terminology typically used in the context of locomotive operations. Understanding the specific signals that directly influence train movement and safety is vital for any locomotive engineer trainee.