Traditional Stone Working
No explosives are used at the quarry, instead the stone is extracted from the quarry face by machine or by drilling and fracturing stone. A good analogy of the quarry face is to compared it with a partially cemented dry stone wall. Where in the quarry's case the vertical joints are cemented together with the mineral haematite in the form of 'brush' ore and horizontal joints 'dry'.
When there is and absence of natural beds or the sheer size of the stone negates the use
of a sledge hammer, the stone is drilled and fractured using 'plugs' and 'feathers'.
fracture line. The picture below shows a drill hole, with 'plug' and 'feathers' inserted.
A 'plug' is a tapered steel wedge which is pushed into the 'feathers' two reversed tapered steel pieces. The plug is driven into the feathers, causing the feathers to expand in the drill hole against the stone resulting in a stress build up within the stone. Each blow delivered to the plug, by the sledge hammer increases the internal stresses inside the stone until eventually a fracture is induced. In olden times dry wooden wedges were driven into notches and soaked with water, until the pressure exerted by the expanding wood, fractured the stone.
Pictured below : A 35 Tonne block pre-drilled, having plugs and feathers inserted prior to breakage.
Below: The block clearly showing the line of fracture.
Below : The split block and the lines of drill holes.
Mine Train Quarry is still worked in the traditional ways of quarrying, the sole concession is in
the use of modern machinery in moving stone and the use of a compressor to supply air to the rock drills.