Heavy equipment has a thing for record months. An excavator puts together a monster four weeks, someone puts out a write-up with the crew lined up in front of the bucket, and everyone moves on. I get it. A huge month makes a good story, but it doesn’t tell you a whole lot about what a machine does after it’s been grinding away for a year.<\/p>\n
Which is why a result Thiess published in July caught my eye. Thiess is a mining contractor that runs sites in Australia, Asia and the Americas, and this time it put out numbers for a single Liebherr R 9600 covering a full 12 months. It also said how many hours the machine actually spent working to get there, and that’s a figure these announcements tend to skip.<\/p>\n
So how much dirt are we talking about?<\/p>\n
According to Thiess’s announcement<\/a>, the excavator moved roughly 22.2 million bank cubic yards of material (17 million bank cubic meters, the metric figure Thiess uses) at MACH Energy’s Mount Pleasant Operation. That’s an open-pit coal mine near Muswellbrook, in the Hunter Valley of New South Wales. Thiess puts 6,840 operating hours behind that figure, counted from the start of last July to the end of June.<\/p>\n If “bank” seems like an odd word to stick in front of a volume, it basically means the material gets measured the way it sat in the ground, before anyone blasted or dug it. Dirt and rock fluff up once they’re broken loose, so the same load takes up more room in a truck than it did in the ground, and counting in bank cubic yards gives you the smaller, more honest number.<\/p>\n Thiess calls this a world record for an R 9600 over a 12-month stretch. That’s a record for one model of excavator. I can’t find an independent body that keeps score on this sort of thing, so it’s Thiess’s claim, and you can weigh it that way.<\/p>\n It’s still a frankly ridiculous amount of ground. The Bureau of Reclamation<\/a> says crews excavated more than 5.5 million cubic yards of material to build Hoover Dam, and this one excavator moved about four times that in a year.<\/p>\n A year has 8,760 hours in it. This excavator logged 6,840 of them as operating hours, or about 78 percent. Operating hours are pretty much the time the machine was running and doing its job. The rest of the calendar goes to things like servicing, repairs, shift changes and all the little delays that stop a mine for a few minutes at a time.<\/p>\n Thiess hasn’t broken down the other 1,920 hours. So I can’t tell you how much of that was planned maintenance and how much was stuff going wrong. But I’d argue that 78 percent is the most useful number in the whole announcement. If you’ve ever owned a truck that spent more time at the dealer than in your driveway, you already know a big machine that’s sitting still is just a very expensive lawn ornament.<\/p>\n Rae O’Brien, Thiess’s group executive for Australia East, said that “achieving a world record of this scale requires consistent execution over time.” It’s corporate-speak. But she’s right about the time.<\/p>\n Spread the volume across those hours and you get about 3,250 bank cubic yards for every hour it ran. A cubic yard is a box three feet on each side. So picture roughly 3,250 of those boxes coming out of the ground every hour, and keep in mind that’s an average, with the slow hours and the busy ones baked in.<\/p>\n Liebherr ran a story about this exact excavator in its customer magazine in April<\/a>. It said the R 9600 moved about 2.24 million cubic yards in its first full month at Mount Pleasant. That beat the site’s previous monthly best of about 2.15 million cubic yards, which another R 9600 working the same mine had set.<\/p>\n For some context, Liebherr-Australia application engineer Harvey Konya said in that story that around 1.3 million cubic yards in a month is already beyond what counts as exceptional for an excavator this size. Ryan Fox, Thiess’s project manager at Mount Pleasant, sounded like he was just getting started: “Today’s record is tomorrow’s target.”<\/p>\n Personally, the year impresses me more.<\/p>\n Split Thiess’s 12-month figure evenly and it comes to about 1.85 million cubic yards a month, against 2.24 million in that record month. An average month landing below the best one is what you’d expect over a year. But this machine averaged well above Liebherr’s own idea of an exceptional month for 12 months straight, and that’s arguably the harder thing to pull off.<\/p>\n The two companies don’t quite agree on when the digging started, either. Liebherr and Thiess give start dates about two weeks apart. That gap leaves the annual total alone, but it makes it tricky to line the record month up neatly inside Thiess’s 12-month window.<\/p>\n It’s Liebherr’s hydraulic mining excavator in the 600-metric-ton class, which works out to around 660 US tons. Class is the important word there. It’s a size bracket, so this particular machine could weigh a bit more or less than that.<\/p>\n It’s also a long way from the heaviest excavator you can buy. Komatsu’s biggest one<\/a> is a good deal heavier, and if you want to see where some of these giants are heading, Fortescue now runs a fleet of electric excavators that drag a power cable around an iron ore mine<\/a>.<\/p>\n A machine like the R 9600 has one job, and it’s to sit at a dig face and fill haul trucks, one bucket at a time. So a year like this depends on the trucks, the dig plan and the mechanics as much as the excavator. Thiess credits its maintenance crew with keeping the fleet reliable, its technical services team with planning the dig, and its operations team with tuning dig sequences and haulage. That reads a lot like the standard corporate thank-you list. In this case, I think it’s probably just accurate.<\/p>\n One thing I’d love to know is how much of that 22.2 million cubic yards was coal, and how much was overburden. That’s the rock and dirt miners have to strip away before they can reach a coal seam. Thiess counts all of it as material moved, and its announcement doesn’t split the two apart.<\/p>\n Thiess announced the 12-month result on July 6. Fox had already told Liebherr for that April story that he believes his crew can get to about 2.35 million cubic yards in a single month, and that it’s their next goal.<\/p>\n","protected":false},"excerpt":{"rendered":" Heavy equipment has a thing for record months. An excavator puts together a monster four weeks, someone puts out a … <\/p>\nHow much of the year was it actually digging?<\/h2>\n
This machine already had a record month<\/h2>\n
So what is an R 9600, anyway?<\/h2>\n