What is the minimum number of openings required for a manhole (MH) up to 12' in depth?

The minimum number of openings required for a manhole up to 12 feet in depth is two. This requirement is in place to ensure adequate access for personnel who may need to enter the manhole for maintenance, inspection, or repairs. By having at least two openings, safety can be maximized; one opening allows for entry while the second provides a means for ventilation or rescue if necessary.

Additionally, having multiple openings can facilitate easier access for equipment and tools, thereby improving the efficiency of work performed within the manhole. This configuration helps to prevent the accumulation of hazardous gases and ensures that workers can enter and exit safely, especially in deeper manholes where the risk of entrapment or asphyxiation is increased.