When should yellow-red flags be displayed in relation to a Form B track bulletin?

Yellow-red flags are employed as a visual warning system to indicate specific conditions or actions that need attention on the track. In the context of a Form B track bulletin, displaying yellow-red flags plays a crucial role in ensuring the safety of train operations in relation to track work or other hazards.

When a Form B track bulletin is issued, it outlines specific areas of track that are affected and the precautions that must be observed. By displaying yellow-red flags one hour before and after the bulletin's effect, it signals to train crews and other personnel that they need to be cautious and prepared for any potential hazards during that entire timeframe. This approach maximizes safety by providing clear visual cues ahead of time to alert everyone involved in train operations about the potential dangers, allowing them to adjust their actions accordingly.

This timeframe includes the active period when the conditions specified by the bulletin are in effect, as well as a buffer before and after. This is essential because it helps to prevent accidents that could occur due to a lack of awareness of changing track conditions or ongoing work. The flags serve as critical indicators for maintaining safe practices during these periods.