Entering the Gate End

of the safety zone and will begin to advance. Because adjacent shields are not allowed to be off the roof at the same time, shields 1 through 5 will not all advance at the same time. Instead, alternate shields will advance simultaneously, followed by the remaining shields.

When cutting out at the endgate, the shearer needs to reach a reference point so that the program knows the shearer is ready to change directions and go to the next turn point. For the headgate, this reference point is set by parameter “HG Turn Point”. Setting this parameter to 7 means the shearer position has to reach shield 7 or less every time it cuts out at the headgate.

Parameter "HG Turn Point”

For the tailgate, this reference point is set by parameter “TG Turn Point from TG”. Setting this parameter to 5 means the shearer position has to reach the 5th shield from the end of the face every time it cuts out at the tailgate.

Parameter "TG Turn Point from TG”

The best way to determine these values is to tram the shearer to the stop points at each end and then set the parameter 2-3 shields towards mid-face. For example, when going into the head gate, if the shearer reaches number 7, then set the “HG Turn Point” to 9. This way the turn point will always be reached. When the SRB position reaches the HG or TG Turn Point, then the shield system is ready for the shearer to travel back to the next turn point in the mining cycle. The next © Caterpillar