I have a bunch of notes that I haven’t turned into posts; this is one of them.
You can see signs of South Africa’s mining history if you travel around Joburg at all. Remember that Joburg wouldn’t exist if it weren’t for mines – it is the largest city in the world not on a river or body of water. As you fly in over the city you can see scarred circles in the earth that are defunct mines; Joburg has generally built itself around them, and the effect of modern homes next to what looks like a festering wound in the earth is a bit jarring. As technology has improved it has sometimes become economically viable to re-process the waste, so some of the man-made hills are now disappearing again.
Camelthorn tree. For perspective, the larger thorns are as long as my finger.
Driving to the mine I worked at in Northern Cape is impressive. It doesn’t look that big from a distance, but as you approach you realize that it’s the proportions (long and low) that make it seem smaller, not the actual size. A massive berm rises above flat grasslands and stunted trees. I’m probably misjudging this, but I would guess the berm – the waste excavated from the pit – is likely ~150 ft tall. While that is big for a mound of dirt that stretches the entire pit circumference (possibly 30 km), even more impressive is the view from the edge as you look inside. The pit walls are built up as the pit is excavated down. Cresting the hill for the first time and looking down inside is like discovering an underground world that has been exposed. Bakkies (pickup trucks) look like ants; the industrial dump trucks look like the Hot Wheels-sized versions of themselves. That’s saying something when each truck can haul >250 tons and is larger along every axis than a portable home.
These dump trucks have electrical contacts so they can use electric motors to supplement the diesel engine going uphill; engineers will appreciate the extra (and efficient) power this provides at low speeds.
You can see signs of South Africa’s mining history if you travel around Joburg at all. Remember that Joburg wouldn’t exist if it weren’t for mines – it is the largest city in the world not on a river or body of water. As you fly in over the city you can see scarred circles in the earth that are defunct mines; Joburg has generally built itself around them, and the effect of modern homes next to what looks like a festering wound in the earth is a bit jarring. As technology has improved it has sometimes become economically viable to re-process the waste, so some of the man-made hills are now disappearing again.
Driving to the mine I worked at in Northern Cape is impressive. It doesn’t look that big from a distance, but as you approach you realize that it’s the proportions (long and low) that make it seem smaller, not the actual size. A massive berm rises above flat grasslands and stunted trees. I’m probably misjudging this, but I would guess the berm – the waste excavated from the pit – is likely ~150 ft tall. While that is big for a mound of dirt that stretches the entire pit circumference (possibly 30 km), even more impressive is the view from the edge as you look inside. The pit walls are built up as the pit is excavated down. Cresting the hill for the first time and looking down inside is like discovering an underground world that has been exposed. Bakkies (pickup trucks) look like ants; the industrial dump trucks look like the Hot Wheels-sized versions of themselves. That’s saying something when each truck can haul >250 tons and is larger along every axis than a portable home.
These dump trucks have electrical contacts so they can use electric motors to supplement the diesel engine going uphill; engineers will appreciate the extra (and efficient) power this provides at low speeds.
No comments:
Post a Comment