Over two miles long, nearly a mile wide and currently almost 2,000 feet deep. It’s a pit that is massive. Some would say…super.
For the full story, check out Take a tour of the Super Pit: The largest open-pit gold mine in Australia.
The town of Kalgoorlie has the feel of an Old West mining town…which I guess is appropriate.
There’s an odd feeling of money here, with many new and expensive cars, and lots of shops and restaurants.
That mountain in the distance is actually just some of the dirt, rock and detritus dug out of the Super Pit in the hunt for gold. Over 200,000 tons of rock gets hauled out per day.
Not an actual accident, but a staged reminder of what could happen if people don’t pay attention. This truck was actually driven over by one of the gigantic dump trucks you’ll see in the next image.
Here one of the dump trucks heads to the repair yard. The glowing number on the back is also on the sides, and lets anyone nearby use the radio to contact the driver, without knowing specifically who’s driving.
How big is big? Check out the next image.
Yeah, like I said. Big. Over 20 feet tall and 42 feet long.
Note the mechanic near the wheel (which are nearly 12 feet tall).
This massive machine is just for changing the tires on the dump trucks.
What do you use to fill a house-size dump truck? How about a garage-size scoop?
The Super Pit wasn’t always a pit. For 90 years the area had over 2,000 miles of traditional (and hand-dug) mine shafts and tunnels. The wood and metal from these must be disposed of separately, lest the chemicals (like arsenic) leach into the environment. (Check out the state government's plan for future sustainability of the Kalgoorlie area, and a more in-depth look at the environmental impact of open pit mining.)
The Pit is mostly goldless rock. To get at the gold, they have to dig down to it, and that means terraced steps and roads.
The red topsoil, one of Australia’s more iconic colorings, comes from a high amount of iron.
This image also gives a good perspective of how huge the Super Pit is.
Those trucks from earlier images? That’s them as dots down the bottom.
The gray rock is some of the oldest rock in the world, at around 2.8 billion years.
See the tiny squares? Those are old mine tunnels the Super Pit exposed as it was dug deeper.
This image is an overview of an area of rock they blasted while I was there. The rows of dots in the middle left (see closeup on the next slide) are the charges.
The charges are set.
Normally they schedule blasts during shift change or lunch breaks. They get everyone out of the mine, blast, then everyone goes back in.
The blast itself was unremarkable. Just a puff of smoke. Granted, I was clear on the other side of the mine.
To keep dust in check, an immense quantity of water is sprayed on the roads and piles of rock.
Since most of the people who work at the mine live nearby, they have ample motivation to keep dust and noise to a minimum.
Though spread out, there’s always something going on. Trucks both loaded and empty move up and down the ramps. Pumper trucks spray water on roads. Excavators dig out loose dirt and rocks.
This is another shot to give you an idea of scale. Note the white pickup truck on the right.
The excavators are way too slow to come out of the Pit during shift change, so the operator heads down in a pickup truck to relieve his day (or night) shift counterpart.
At the depth they’re at now, there are roughly six trucks worth of useless rock for every one that has gold in it. As they near the bottom, that will be closer to 1:1.
Each 793C costs around AU$4 million, but they help the Super Pit generate about AU$3 million a day.
Each shift is 12 hours. After a few weeks on, you get a break, then you do night shifts. Then a break, then day shifts. There’s no penalty for being tired though. If you get woozy, you can call your boss, and a relief driver will come down and take over for you. Too much money and too many lives are at stake to risk tired drivers.
Each of those tires weighs 5 tons and costs $40,000.
With a top speed of 33 mph…on flat ground, the 793C isn’t exactly a Hennessey Venom GT.
Nor would you want it to be, since even at those slow speeds, even a slight contact with a wall would mean tremendous damage.
At the top of the Pit is this cistern, which supplies the pumper trucks their water so the dust doesn’t get out of hand.
The water for the town is actually piped in from Perth. On the ride to the Pit, we paralleled the white-painted tube all the way.
All that rock gets brought up here and has to be processed to get the gold out of it. That cylinder in the middle is one of several involved in crushing the rocks into dirt.
Hundreds of steel balls get fed into the crusher, along with tons of rock. As it all spins, the balls pound the rocks into submission. Different size balls are used at different stages of the process.
You want to know what it takes to extract gold from rocks? It takes steel balls to extract gold from rocks.
These hoppers hold the soon-to-be-crushed steel balls. You see, rocks don’t turn to dust easily, and these steel balls will make the supreme sacrifice for the cause.
Over time and constant tumbling they get worn out to the point of being useless, so there needs to be a steady supply.
These are about the size of a grapefruit.
Finally, after all that, gold! Tiny, tiny traces of gold, mixed in with pyrite. The ground around this conveyer belt was sparkly with “gold.”
This will be processed further to separate out the fool's gold from the real.
The gold actually gets made into bars on site. Unfortunately, we weren’t even allowed to show the building where it happens. I can tell you it was completely non-descript, which is probably the point.
Just take a moment and imagine barreling down an Australian highway at 80-plus mph, oncoming traffic a few feet to your right, and one of these road trains blows past you.
In case there’s an issue in the mine, the processing goes on so there’s no downtime with the rest of the operation. Here, you can see one of the storage areas that holds ore waiting to be processed. The metal teepee cover is to help keep the dust contained.
There’s actually another mine next to the Super Pit called Mt. Charlotte. Its ore is also processed at the Super Pit’s plant, and brought to the site using a really long conveyer belt.
The Super Pit is active 24 hours a day, every day of the year. It only shut down once since it opened, right after an earthquake in 2010.
For the full story behind this tour, check out Take a tour of the Super Pit: The largest open-pit gold mine in Australia.