What action must crew members take when moving at restricted speed?

When moving at restricted speed, crew members must keep a lookout for broken rail and be prepared to stop within half the range of vision. This practice is essential to ensure safety when visibility may be limited or when operating in areas where track conditions may be uncertain. The requirement to stop within half the range of vision allows for timely reactions to any obstructions or hazards that may present themselves on or near the tracks, thus minimizing the risk of accidents or derailments.

The importance of monitoring for broken rail cannot be understated, as this can severely compromise train safety. The practice is in line with the underlying principles of operating at a speed that allows for sufficient reaction time to unexpected circumstances. Hence, maintaining this vigilance is a critical component of responsible rail operation, especially under conditions where restricted speed is warranted.