What permission is required for a stone train to occupy the main track from Prima DEF?

The correct answer indicates that permission from the RWIC (Roadway Worker In Charge) is necessary for a stone train to occupy the main track from Prima DEF. This requirement is in place to ensure safety and adherence to operating rules, as the RWIC is responsible for managing work zones and ensuring that all movements in the area are safely coordinated.

The RWIC's authorization is crucial because it ensures that all safety protocols are followed and that there’s clear communication between the stone train and other train operations in the vicinity. This authorization typically includes confirming that the track is clear and that any work-related procedures are in place to guard against potential hazards.

In contrast, other options do not provide the same level of oversight needed for such operations. For instance, a General Notice might relay information but does not confer direct permission. Approval from the Engineer could pertain to operational decisions but does not specifically address the immediate requirement for track occupancy safety that the RWIC's permission provides. Similarly, Form L clearance relates to specific signaling and track occupancy arrangements but does not replace the need for active control and safety measures managed by the RWIC.