Just wondering how accurate the lift charts are on these mini's. I'm looking to off load a (1200 lb) 500 gallon empty propane tank with a 35 size mini (8000lb). Any words of wisdom?
You should not have a problem. Although if I were to do it, I would likely drive the mini up to the tank (perpendicular to the tank) and put the blade down, slightly elevating the front of the tracks. I would hook up to the tank and lift the tank up off the trailer, making sure the machine could hold the tank up without going over relief. I would then drive the truck or trailer out from under the tank and set the tank down.
excavators' lifting power is mainly at ground level below ground. close is the key.. don't swing until it is close to the ground. we've had to bring in cranes on some jobs, because the hoe wouldn't pick the pipe off the trailer... this was a 600 Komatsu, which is big.. once it was on the ground it would pick the pipe fine. it was that extra 8' of height that just killed it's ability to lift.
that should pick it up, just use common sense and pay attention, follow what the others said.
Remember the lift charts refer to the dipper arm being naked (ie, no bucket, hitch or thumb). With heavy loads you may well find that the boom won't lift it but the dipper arm will. Make sure you sling it well (if there are no lifting points on the tank make sure to go around the tank twice to stop the chain/rope/sling from sliding) and use ropes to hold the tank , if it is likely to turn during the lift. Make sure that the ropes are long enough so the helpers can stand well clear of the lift. Think it through and double check everything.
I'm thinking I'll do what KSSS suggests and test the lift before getting to carried away. Fortunately the tank has good lifting lugs but they are spaced about 8' apart which gives me grief with the angle of the slings being derated so much. The backup plan will be a 12 ton picker truck.
It should pick it up, just keep in mind simple physics