Ex-miner’s rock ‘remedy’
Tuesday, 1st November, 2011
By Erica Visser
Contractors for the city’s new multi-million dollar shopping centre had overlooked a better option for breaking the hard rock on the site, according to a local man with more than 40 years’ mining experience.
Work has been on hold for months as the developer and contractors try to find the best way to remove about 3000 cubic metres of rock.
Last week the developer, Leasecorp’s Steve Palyga, said that the company was investigating a non-explosive product called NoneX.
City Council’s Building and Environmental Health Manager, Geoff Laan, described it as the best option.
But retired miner Peter McManus said that he had worked with NoneX and another similar substance, Expando, extensively and that Expando was superior because it was more environmentally-friendly and would keep more locals in work.
While NoneX requires a licensed user from outside the city to complete the work, Expando can be used by local labourers, Mr McManus said.
“Expando is a non-explosive and non-toxic chemical agent that can be used by any experienced person,” he said.
“I am sure there would be a couple of companies in Broken Hill that would be capable of carrying out the drilling, breaking and removing the amount of rock that is on the site using the Expando method.”
John Rothwell, the owner of the company that makes Expando, No Blast Pty Ltd, said that it can be used on construction sites by labourers.
Unlike NoneX, which causes some underground vibrations and requires a taped-off exclusion zone, Expando is mixed into a putty and cracks rock as it heats underground.
“Both methods incur drilling holes, so whichever way they go is going to be expensive,” Mr McManus said.
“Expando is roughly about $1.80 per drilled metre and if anything, the product would be cheaper than NoneX.”
He said the only disadvantage was the time it took to break the rock.
“Basically they both crack rock - NoneX does it really quick, but it also does create a little bit of noise and some vibration,” Mr McManus said.
“Expando does take longer to use. It takes two to six hours to put in and up to three days to work but what’s a few days when they haven’t done anything for months?
“It’s definitely a safer product. It doesn’t throw any rock around and it doesn’t require electricity.”
Mr McManus said he wanted to make sure contractors considered other non-explosive methods.
“There’s other alternatives rather than blasting or using NoneX,” Mr McManus said.
“Why give these ‘experts’ from out of town work when there’s people in town to do it?”
Mr Palyga said that he could not comment on the matter but would discuss it with contractors.