G’day all, What, if any, is the difference between operating a 30t digger to operating a 400t digger? All the 400’s I’ve seen operate like they have Valium in the fuel tank. Cheers in advance guys.
Good day All of the larger machines have slower cycle times than that of the 13 -26 ton machines , if you watch the large mining machines load it is really slow compared to smaller excavators. Kind regards Uffex
Smoothness is the key on a big machine. You can't accelerate hundreds of tons when swinging like you can 30 tons. Big machines load trucks all the time where a 30T machine might spend a lot of time simply moving dirt into or out of a hole and dumping it on a pile. Correct set-up and reducing the swing angle to the minimum for truck loading is critical. Big machines may seem slow and ponderous but by golly they can move dirt when measured in what they move per operating hour. We have 350-tonne machines that are moving around 3000 tonnes/hour in good digging.
If anyone had a pic of the pinion gear(s) from one of these diggers, it would be interesting to see. I would venture a guess that there would be at least 2, and they're probably 2' in diameter.
4 actually. Even something like a 60-ton machine would have 2. We changed a swing bearing and all the swing drives in one of ours not long ago. I’ll see if I can round up some photos
Big machines might look slow but those buckets are moving huge amounts of material on each pass.
There used to be a dragline not far from me. It looked like a barn with a crane attached. First time I saw it, I was delivering a load of pipe. I parked about 250 feet away from this barn, and wondered what kind of crane was on the other side of the building. A loud buzzer sounded, and the boom picked up, and the barn started to swing around. Took me a moment to process what I was looking at. I got a quick tour. The barn, or cab swings slow enough that you can climb aboard while she swings, but as the operator pointed out, the end of the boom is moving a lot faster, and that bucket looked big enough to park a couple tandem trucks side by side.
Hitachi EX3600 swing bearing replacement. Suspended load as per photo in the region of 140 tonnes give or take. Guide bolts on upper frame were aligned with the holes in the bearing using GoPros fixed to the frame so that the cranes could be signalled without the need for anyone going underneath a (large) suspended load to line everything up.
A bloody smart idea that Nige.
Thanks heaps for all of your replies. Are the controls identical in the bigger machines?
All the controls basically do the same 4 functions - Boom up/down, stick in/out, swing left/right, & bucket curl/dump There are a number of different control patterns between different manufacturers, so movement of a particular joystick on a particular make of machine may not result in a movement of the same function as it would on a machine from a different manufacturer.
I was reading that the Bucyrus 3850B stripping shovel would swing from 0-25 MPH! The end of the boom probably felt like 100 MPH. They had to pull the tub out of Big Muskie to make repairs and it took 22 major pieces of earth moving equipment to do it. I couldn't find the picture.
I knew a guy that crawled out on the boom of one the big draglines out at Falkirk to do some welding. He said that was an adventure. He figured he was moving 40 mph.
The drag line I was talking about is on this forum. The Maid Marion. I think it is in Australia now
Friend of mine years ago was sent to one of the coal mines by the Boilermakers union. He's normally a pressure welder but they were waiting for something so asked if he could do some welding on a drag line boom. The cables are already strung out on the boom and you just hook your stinger up. He goes up, grinds out the crack and as he's preparing to start welding, the machine starts moving. ***!!! He gets on the radio and tells the foreman he's up on the boom doing repairs. Foreman tells him they don't shut the machine down for minor repairs. He said, in no uncertain terms, to find another welder. He was about 1/2 way up and also said he felt it was going 50 MPH. I think the new rules don't allow the machine to run when they are on the boom. I think that would scare the crap out of most people.