How long before the arrival of trains must workers move to safety according to the lookout's duty?

Workers must move to safety 15 seconds before the arrival of trains as specified in the lookout's duty. This timeframe ensures that there is adequate warning and reaction time for individuals to clear the tracks or any potentially hazardous areas before a train approaches. The emphasis on this specific duration is rooted in safety protocols that aim to prevent accidents and ensure the well-being of all personnel on or near the railway. By adhering to the 15-second rule, workers can take the necessary actions to avoid dangerous situations effectively.