Tunnel shield for use in coal mines and method

摘要

Tunnel shield 11 for use in advancing the roadways associated with long wall coal faces comprising forward and rear sections 21, 23 which can be advanced relative to one another, e.g. by hydraulic rams 25 extending between the two sections, there being anchoring pads 27 on each section for anchoring the section to the tunnel wall while the other section is being advanced. Preferably, a bridging skin 49 is provided between the two sections and a tail skin 47 is provided on the rear section 23 beneath which a rack 51 for prefabricating tunnel supports is located. The shield skin is partly open at one side to provide access to the coal face and both sections are preferably supported on hydraulically operated feet 31, 35 for lowering off purposes. By using the shield to advance roadways, propping of the roadways can be carried out in a safe area at the rear of the shield rather than in the traditional location adjacent the head of the roadway where access to the coal face is always required.