What is a primary concern regarding haulage equipment in doors?

The primary concern regarding haulage equipment in doors is that it can obstruct airflow. In underground mining operations, proper ventilation is critical for maintaining a safe working environment. Airflow is essential for diluting harmful gases and ensuring adequate oxygen supply for workers. When haulage equipment obstructs airflow, it can create areas with poor ventilation, leading to increased risks of hazardous conditions, such as the buildup of toxic gases or a lack of breathable air. Consequently, maintaining clear pathways for air circulation is crucial for the safety and health of all personnel working in the mine.