779. Firedamp drainage in coal mines.

779.     Firedamp drainage in coal mines.

At coal mines, regulations1 make provision as to the process, known as 'firedamp drainage', of collecting firedamp2 in the mine before it has been diluted by any ventilation and its safe disposal3. Requirements are imposed in respect of firedamp drainage systems4, as to the drilling of boreholes5 for tapping firedamp6 and the facilities to be provided at each borehole for measuring the percentage of inflammable gas in the gas flow7; the insertion, sealing and methods of connection of stand pipes in boreholes8; the design, construction, installation,