Norm Tollinsky is editor of Sudbury Mining Solutions Journal, a magazine that showcases the mining expertise of North Bay, Timmins and Sudbury. This article is from the December, 2013 issue.
Ground conditions, water ingress and a 60-year-old timbered shaft among the challenges overcome
When Bob Booth and Gary Annett of the Totten project team hand over the reins to mine manager Dave Pisaric on December 31st, life won’t be near as exciting.
Few mine development projects go exactly as planned. Mother Nature can frustrate the intentions of the most experienced and skilled engineers and geoscientists, as happened at Totten when unfavourable ground conditions and water ingress began bogging things down.
The team stepped it up a notch, hunkered down…and saw it through. Vale decided against the engineering, procurement and construction management (EPCM) approach and kept the project management in house.
Annett, with the ominous title of Totten execution manager, was assigned to Totten in February 2008. A 15-year Vale and Inco mining engineer and alumnus of Laurentian University, Annett worked his way up through operations and spent eight years at the company’s Coleman Mine.
Bob Booth, a 23-year veteran, transferred from operations to project management in 2000. He oversaw the Creighton Deep project from 2000 to 2007, served in several senior engineering and management roles both in Thompson, Manitoba and Sudbury, and was assigned to the Totten team as project manager in February 2011.
Keeping project management in-house eliminates a third party from the equation, allowing for quicker decisions when challenges are encountered, said Booth. The size of the team has to be appropriate though.
“When you bring in an EPCM team, you bring on a full suite of systems. When I arrived, there was a very small team here, so we had to grow it and the robustness of the systems to be able to deliver,” said Booth.
The project team defined a new level of excellence and trumpeted the “One team, one way to zero harm” mantra to the 500 workers from multiple contractors crossing paths and interacting at the site.
“The colour of your coveralls didn’t matter,” said Booth. “It didn’t matter if you worked for this engineering company or some other engineering company, Cementation, SCR, Technica. It was about all working toward the same goal. That’s what made us successful. It was a team effort from everyone.” One of the key indices of excellence in the mining industry is safety, and on this score, the results were world-class, said Booth.
“There are no mines that I’m aware of in North America that have an annual recordable injury frequency of 3.58. We set up the system in 2011, were middle of the pack in 2012 and this year we’re leading the pack.”
In September, the Totten team celebrated one million man hours without a lost time injury.
The mine development process began in 2006 with the construction of a wastewater treatment plant. “We had to complete the wastewater treatment plant before we could pump out one millilitre of water from the mine workings,” said Annett.
The plant, designed by AMEC, pumped out one million gallons of water from the mine, clearing the way for a thorough inspection of the shaft. The Totten Number 2 timbered shaft descends 4,130 feet. The challenge was to take a 47-year-old shaft and make it like new, said Booth.
“We don’t build timbered shafts anymore, so we had to find the right people to do this type of work. We were lucky to have Cementation on board. They had some experienced old-timers who understand timbered shafts.”
The timbers weren’t in bad shape, said Booth. Immersion in water was actually a good thing because they didn’t dry out.
A thorough classification of the ground was performed and appropriate ground support installed to stabilize challenging ground conditions, including ‘bookcasing’.
“We weren’t able to use modern-day ground support with screen and bolts, so we created concrete wall sets,” said Booth. “We classified the whole shaft from surface to the 1850-level to decide the treatment that would be required to reduce risk based on the ground in certain areas.” Beyond the 1850 level, concrete rings lined the shaft. The nine-foot by 18-foot shaft is serviced by a 16.5-foot Davey- Markham hoist and two conveyances supplied by FLSmidth and Stainless Steel Technology. There are two conveyances – an 18-tonne skip, a second 15-tonne skip with an underslung cage for 17 and a two- deck Marianne accommodating eight people in tight quarters.
There are five levels off the shaft, but only two main mining levels – 3150 and 3850. Totten had very limited lateral development.
“There was some development on the upper levels, but we aren’t using any of it,” said Annett. “We’re going after deeper ore.”
The project team oversaw 43,200 feet of lateral development, which was completed in August of this year.
“We went a bit smaller – 14 x14-feet for the drifts and 14 x 16-feet for the ramps – because of the smaller equipment we’ll be using – 30-tonne trucks and six-yard scoops instead of 50-tonne trucks and eightyard scoops,” said Annett.
Cementation drilled two ventilation raises from surface to the 1850 level – an 18-foot diameter fresh air raise and a 16-foot return air raise. Beyond the 1850 level, Redpath’s raiseboring group drilled several fresh and return air raises to the 3150 and 3850 levels – mostly 12-footers except for one 16-foot return air raise between the 3150 and 3850 levels.
A rebuilt Pitnam crusher on 3880 level will be more than sufficient to handle eventual output of 2,200 tonnes per day.
From a project management perspective, the main challenge, aside from the ground conditions and water ingress, was the sequencing of all the construction in the shaft with the delivery and installation of the infrastructure underground, said Booth.
“I think we’re both going to be bored when we move on to the next project.”
Tagged Bob Booth, Cementation, Coleman Mine, Gary Annett, Laurentian University, Occupational safety and health, Stainless Steel Technology, Sudbury, Totten Mine administration