Aboroginal groovings had been discovered on sandstone next to a creek bed, these were deemed of important archeological heritage and had to be preserved. Long Wall mining was programmed to take place underneath the location and a plan was developed, between ourselves, the contractor and the client, Xstrata Coal. We were engaged by the contractor as technical advisors.
We had gained a reputation for difficult projects, having previously worked on a site of significant Aboriginal heritage importance, we were well placed to offer technical advice.
The plan was to saw cut and remove blocks either side of the groovings, storing the blocks for re-instatement 6 months later, then use a down hole hammer to drill 100mm dia. holes at 300mm centres along the length of each, to a depth of 40 metres.
After the two saw cuts, 1.2 metre apart x 700mm deep and 25 metre long, we did one cross cut then used the core drill to form splitter holes and split blocks out at 1 metre spacings, numbering each block and side wall.
After two weeks, all blocks were out. The water pump was used to pump out water after rain, as electric pump could not remove sufficient volume. It was an interesting project, re-instatement took place two years later when all numbers had washed off!!!
How we solved the giant stone jigsaw puzzle in the re-instatement works, as someone had moved the blocks around, is another story, but it won an environmental award for Xstrata Coal!!!