|Cone crushers presented two problems for this West Belfast quarry: awkward access for housekeeping on one; manual clearance of frequent blockages on the other. The solution to the first lay in a mini-tracked dumper-loader able to access the tail drum of the conveyor, scoop the spillage and carry it up and out of the tunnel. The blockage problem was caused by the discharge conveyor below the cone slowing or stopping. It was solved by fitting a ram operated hinged plate above the feeder. Now, when the tacho senses a drop in conveyor speed, the feeder is stopped and the ram activated instantly, preventing material entering the cone.