Roof Bolts In Coal Mines

The traditional dead weight loading design.

Roof bolts in coal mines.

Roof bolting is hard work where miners often have to lift cumbersome pieces of heavy metal into awkward positions. The coal mine roof rating cmrr somewhat quantifies this effect through the strong bed adjustment 9. Mining roof bolters operate machinery to install roof support bolts in underground mine. Jennmar is the largest manufacturer of roof control products in the u s however we don t stop there.

Short operating length allows bolting the first row of an intersection from one set up. Experience has shown that roof bolts are extremely efficient in the suspension mode 6 7 8 though suspension becomes more difficult if the weak layer is more than 3 ft thick. In low seam mines the flexibility of the cable bolts allows greater length supports to be installed near the advancing face without the use of couplers. Roof bolts in helping to create a stable rock structure are the first line of defence to protect mineworkers from fall of ground related hazards which highlights the importance of correct roof.

Perhaps the most significant development in coal mine ground control during the last century was the introduction of roof bolting during the late 1940 s and 1950 s. Pull down loose rock that cannot be supported. Wide boom swing allows multiple bolt installations from one chassis position. From an engineering standpoint roof bolts are inherently more effective than the wood timbers they replaced.

They also drill bolt holes into roofs at specified distances from ribs or adjacent bolts. Cable bolting is sometimes used as primary support in coal mines experiencing difficult roof conditions. Low version of fletcher s rr ii with machine height as low as 25 635m. Independent front and rear lift for easy tramming on uneven bottom.

When conditions change and the miners are out of their element safety can become a concern. We can supply the construction mining or tunneling industry with much more. Take a look at our capabilities and affiliates to learn more. Roof bolts promised to dramatically reduce the number of.

Low profile roof ranger ii. Since the introduction of roof bolts in the coal mines during the late 1940s and 1950s roof bolts promised to dramatically reduce roof fall accidents.