What is the maximum bearing surface of jacks used for roof support?

The maximum bearing surface for jacks used in roof support is established to ensure adequate strength and stability in underground mining operations. A bearing surface that is too small may lead to failure of the support system, which can pose significant safety risks to miners. The 36 square inches specification is based on engineering practices that consider the load distribution and the properties of the rock formations encountered in coal mining operations.

When selecting jacks for roof support, it is crucial that they provide sufficient support to safely hold the rock and prevent collapses. The 36 square inches allows for an effective distribution of the load across the bearing surface, helping to reduce the potential for localized failures that can occur if the supporting system is inadequately sized.

Therefore, this specification is designed to promote safety and stability in mining environments, highlighting the importance of adhering to industry standards in roof support systems.