The schematic ventilation circuit (Figure 1) shows the general ventilation distribution for a mine's two kilometre longwall block. The mine has five mains headings (two intake travel roads A and C, one intake conveyor road B and two returns D and E).

Overcasts Node A is in maingate intake Inbye panels Node A* is in returns adjacent to overcasts 60 m /s 500 m 1500 m B Maingate 55 m /s A A* B A 300 m Tailgate D C 40 m /s D 115 m /s 2 1 Bleeder 2 VVTT Conveyor EDCBA Intake travel Mains Return Figure 1. Schematic diagram of a longwall ventilation circuit