This standard lays down the requirements for timber used for structural supports such as props, cogs, cross bars, and lagging in underground coal mines. It specifies the suitable timber species, dimensional tolerances, and permissible natural defects to ensure structural integrity and safety in mining operations.
timber for use in coal mines
Quick Reference Values
Typical prop length1.5 m to 4.5 m
Typical prop diameter100 mm to 250 mm
Maximum permissible taper10 mm per meter length
Maximum permissible bow/crook1 in 100 of length
Practical Notes
Ensure timber is properly treated with preservatives as per IS 401 if it is to be used in damp, underground environments for an extended period to prevent fungal decay.
Inspect timber for critical defects like severe cross-grain, splits, and large dead knots, which severely reduce compressive strength parallel to the grain.