Jul 2008

Following on from the visit to the Platinum mine, the following day I headed out to the site where the world's largest diamond was found, Cullinan. Cullinan is about an hours drive north east of Pretoria and is an otherwise quite country town, surviving on the back of the diamond mine. The mine itself is surrounded by a mining small village, hospital and fire station; it was interesting to learn that during the early 1900's miners would be required to "living-in" in an attempt to control theft. The mine is over 100 year old and has produced a significant amount of the world's diamonds including the largest which was named the "Cullinan diamond" and is now part of the British crown jewells.
Original production was from an opencut that eventually reached 400m in depth, before underground methods were used. Current depth is 800m bellow surface and uses a modified sub level caving method. The shear size and grandure of the mine is nothing like I have ever seen before, with the workshops and lunch room underground being very well apointed and even includes a fish pond.

Survey methods at the mine include real time monitoring of a nearby road using extensiometers and tilt meters, GPS monitoring of the highwall and fine dam, in addition to the typical control surveys, drivage and grade control. Due to the age of the mine some of the original plans for the area over 100 years old and impressive to see especially the draftsmanship, sadly the one thing that modern drafting lacks.

Back to survey reality here as the team consists of a 3 surveyors and 3 assistants. For a while there I thought every mine had scores of assistants.

The long awaited visit to South Africa has begun. After months of planning I've finally landed in South Africa and have spent the last couple of days with the Mine Surveying Inspectorate, gaining an understanding of their Regulations and how they go about their surveying and drafting audits of Mines. Todays visit was to one of the Platinium mines in Rustenburg, in North West Provence.

The Platinium reef (seam) outcrops in the Rustenburg area and dips away to the North at about 15 degrees. Although some mining has occured by open cut methods, the vast majority of Mines in the area are underground. Access to the underground was very different to what I'm used to and is via a chairlift, not unlike a ski lift, down to the production level, then a 500m walk to the production unit. The Mine is very tidy and presents well but what really impressed me was the fact that they employ 8000 people at this mine, eight thousand! I was initially shocked by their safety statistics of 1 fatality, 52 Lost Time Injuries and 32 Serious Injuries, but taking into consideration the size of the workforce and excepting the fatality, thats not too bad and I'm assured that it is on the improve. The method of mining here is by longwall, but not in the same sence as a typical longwall in an Australian coal mine, but rather the face is drilled and blasted then cleared using a scraper. The supports placed are timber props and the "seam" is only 1.0m thick. Bloody hard work on your knees all day I'm sure. All ore haulage takes place using battery powered locos on rails back to the hopper and onto the belt for transport to the surface up the decline.
The survey office at the mine consists of the Mine Surveyor, Assistant Mine Surveyor, 6 surveyors, 21 assistants and one draftsperson. Wow, wouldn't that be nice back home. The methods of surveying are fairly typical and use Leica equipment for control traverses, direction and grade control. Face pickup is fairly conventional using chainage and offset from existing survey stations.

The return trip from the mine took the scenic route back to Pretoria, through an agricultural area and past the weekend retreat areas visited by these from Pretoria and Johannesburg. Roadside stalls are a frequent sight through out South Africa, with most trying to make a living from selling fruit, vegetables, exhaust systems repairs and hubcaps. Tomorrow I'm off to a diamond mine, gold will be next week. Anyone know a good jeweller?