This type of shield has two sets of legs inclined forward into the canopy and the other two inclined backwards and connected to the goaf shield. The main features of the 4 leg shield are: The front legs connect the base and the canopy and the rear legs connect the […]

Chock shields supports always have 4 hydraulic legs and all 4 legs are connected to the canopy of the support. The legs of a chock shield support are either vertical or inclined but the majority of chock shields have inclined legs as this provides better support pressure to the canopy. […]

Hydraulic powered roof supports are self advancing structures which are interconnected along the length of the longwall face. Each unit along the line is also connected to each pan of the AFC. The function of the powered supports are to: To control strata deformation, fracture and movement around the coal face, To […]