This is the largest digging machine (or trencher or rotating shovel) in the world. It was built by Krupp and is shown here crossing a road in Germany on the way to its destination, an open air coal mine.
Although at the mine the treads are unnecessary, it was cheaper to make the machine self-propelled than to try and move it with conventional hauling equipment. Some factoids:
- The machine is 95 meters high and 215 meters long (almost 2.5 football fields in length)
- Weight is 45,500 tons (that's equivalent to a bumper to bumper line of jeeps 80 miles long)
- It took 5 years to design and manufacture at a cost of $100 million
- Maximum digging speed is 10 meters per minute
- Can move more than 76,000 cubic meters of coal, rock, and earth per day
Annie Rassios commented in the Earth Story, while changing a bit the title to "The World’s Meanest Mining Machine": It may look like a Swiss-army knife from hell, but it is in fact said to be the world’s largest mining machine.
Strip mining is an eyesore of controversy. Some of its few benefits are that it is a safer mining method than underground tunneling; loss of life is highly reduced. Advocates tout that reclamation can benefit regional economic growth – parks, lakes, recreational facilities are often modeled to fill in the retired strip mines. A retired strip mine in Ptolemaiida Greece was reclaimed as a landfill site, now taking the refuse from all the villages and towns in an area of ~9,500 sq km produced by a population of nearly 300,000. This has really benefited our local groundwater quality so I’m glad the dump is there.
But – for the bad, strip mining is destructive of the local environment. It’s ugly. It has the potential for destroying watershed, water drainage, water contamination. No matter what reclamation proponents claim, the Earth simply can’t be put back together as it once was.
The nasty looking thing on the left of this machine is the rotating bucket-wheel excavator that is estimated to be able to strip mine at a rate of 10 meters/minute reaching a daily output of coal and rock of about 224,000 cubic meters. The machine is 95 m tall and 215 m long. It can move on wheels between sites.