How far must fans be offset from the nearest side of the mine opening?

The requirement for fans to be offset from the nearest side of the mine opening is based on both safety and operational efficiency. An offset of fifteen feet is recommended to ensure that the airflow, which is crucial for maintaining safe working conditions, is not disrupted by the mine's opening. This distance helps prevent the direct impact of external elements or weather conditions, which could adversely affect the ventilation system within the mine.

This spacing also allows for adequate maintenance access to the fans, ensuring that they can be serviced without risk of falling debris or other hazards that may be associated with the mine opening. Additionally, a proper offset minimizes the chance of any potential obstructions that could interfere with the fan's air movement, ensuring effective ventilation throughout the mine.

In contrast, shorter offsets might not provide the necessary protection and could lead to ventilation inadequacies, which can compromise safety. Therefore, adhering to the guideline of fifteen feet underscores the importance of safe operational practices in underground mining.