What activities are permitted in an underground mine when only the escapeway is available for use?

The correct choice relates directly to the safety and accessibility requirements that are paramount in mining operations. When an underground mine has only the escapeway available for use, the main focus is on ensuring safe evacuation routes for personnel in the event of emergencies. Therefore, activities that are permitted during this condition are confined to those that maintain or restore the escapeway itself.

Restoring the escapeway is essential because it ensures that the escape route remains in good condition and accessible for miners who may need to use it during an emergency. Maintaining the integrity and functionality of the escapeway is a critical safety measure, as failure to do so could jeopardize the safety of all personnel underground.

In contrast, conducting routine inspections of non-essential areas could lead to unnecessary risks, as those areas might not have the same urgency or safety priority as maintaining the escapeway. Similarly, transporting equipment to the surface or performing maintenance on machinery could create hazards or block the escapeway, making it less safe for emergency egress. Thus, the allowance for activities is strictly limited to those that contribute to the safety and accessibility of the escapeway when it is the only passage available.