Under what condition can maintenance work be performed between machinery or equipment and ribs?

Maintenance work between machinery or equipment and ribs can be performed when the area has been tested and secured if necessary. This condition is critical for ensuring the safety of workers during maintenance activities. Testing and securing the area can involve assessing the structural integrity of the ribs and ensuring that there are no potential hazards, such as falling rock or equipment that may lead to unsafe conditions.

By securing the area, potential risks are mitigated, allowing maintenance tasks to be carried out more safely. This procedure is in line with mining safety regulations that aim to protect workers from accidents that could arise from working in potentially unstable or dangerous areas.

The other options do not adequately ensure the safety necessary for maintenance work. While having an experienced worker present is beneficial, it does not provide the same level of safety assurance that comes from securing the work area. Scheduled maintenance times are important, but they do not replace the need for safety measures. Similarly, working when other workers are not around may not be safe if the environment has not been assessed and secured. Overall, the focus on testing and securing the area highlights a proactive approach to maintaining safety standards in mining operations.