Where will a track permit authorize a train or employee to occupy a main track?

A track permit is specifically designed to authorize a train or employee to occupy a main track under the conditions outlined in the permit itself. This means it is critical for the track permit to identify the specific tracks that are approved for use, and this information is typically found in the timetable.

Designated tracks in the timetable are clearly marked for operations, ensuring that all personnel are aware of where they are allowed to safely operate without conflict with other train movements or maintenance activities. This specificity is essential for maintaining safety and efficiency on the rail network.

The other options do not accurately reflect the purpose or usage of a track permit. For instance, while a track permit may be relevant to activities in a yard, it does not universally authorize occupation of all yard tracks without specific designation. Similarly, permits are not limited to tracks under manual control, nor do they authorize occupancy on any track that is simply out of service unless explicitly permitted in accordance with the rules. Thus, the correct answer shows a clear understanding of how permits function within established operational parameters.