I have an upcoming job moving some small boulders, quite a few actually. I'll be swinging them over nothing but other rocks and dirt, and if the rigging is cheap enough, no big deal if it's shot by the end of the project. These are about 3', +-, boulders, not huge, probably 12 to 1800 lbs, maybe less. The couple times I've moved some in the past, I remember it being a pain to rig, but I was working by myself, and they were much bigger. I'll have two pretty sharp guys this time, and as of now I'm thinking 2 of my 12' x 3/8" wire rope slings. I'll sell them to the guy I'm doing the project for, for around what replacements will cost me, as they for sure will see some heavy abuse getting pulled out, and they are cheap as heck anyway. I don't have any straps I want to basically throw away, and I think the cables will grip OK, though I can see multiple tries until the CG and the pick point is flyable, but that's OK, I'm working by the hour and the helpers are paid for. Another possibility is welding something up out of scrap, or borrowing ( one only in my area, owned by a roofing company) a crane pallet picker, make that a boom truck pallet picker. Whatever we do it needs to be quick to get, and I keep coming back to cable rigging. Any ideas out there?
what about an sds hammer and a 3/4 bit and some eyebolt anchors.... guess it would depend on the type of boulders??? If your boulder size doesn't vary too much I don't see why the rope wouldn't work just go with 3 or 4 pieces shackle them together at one end for the pick and the other for under the boulder... like a basket
I've rigged quite a bunch of rocks building retaining walls. Those rocks tend to be somewhat rectangular, longer and narrow, but usually bigger on one end than the other. I usually use two chains, wrapping one on each end, kind of like rigging a pipe or beam, then I have my 12' cable spreaders with hooks hanging from the ball or block. The chain can adapt for the bigger and smaller ends, making two pick points where the loops are. After setting, you can pop off the hook and make a short loop with it, and pull it out with the crane if its trapped. If you've got really round rocks, you can do the same with 3 or 4 cable spreaders with hooks, and wrap the chain below the center of the "ball". The chain can't come up and off because it can't get bigger, and the rock will kind of just lean into the cable chokers. If you don't have spreaders with hooks, you could do the same with 4 chokers and shackles. Found some pictures. The first one is a chimney cap rock, I used a spreader because I was worried about it breaking, and I didn't have any good notches to hold the rigging out- from sliding in. I didn't want it to drop on the chapel. If I remember right, I had to add some shackles to the one side to get it to pick level so they could put it on the chimney. Second shows a different chimney cap. Third picture shows what I'm talking about with the loop of chain, usually I end up with two loops of chain on the rock, but I think this one we were trying to tip it in under another rock so we only went with one chain and got it balanced. We evidently were using the spreader bar on some of rocks also, because its laying on the rocks to the left of where the guys are standing. Last one was at a resort, they had built this wall and water slide, then got a torrential rain a couple weeks later and it washed under the rocks collapsing it into the water slide. I think we have just a single chain around it here, and we got it kind of lifted up, then added a second chain before I flew it back off the wall, to get down to the sub problem. Then we flew the rocks back in.
I thought I'd throw this picture in as well, its the largest thing I've lifted with cranes I own (I worked for a guy with a 360 ton crane for a while and we did bigger lifts there). . This is a 98,000lbs rock. We were moving it out of the side of this driveway to expand the road. We backed a triple axle lowboy up the road and set it right on top of the rear axles on a road plate. It had the tires squatted pretty hard, and the tractor didn't have enough weight on the drives to make the hill where we offloaded it. We used the chains to hold the cables together on the rock, I just didn't want them to slide apart and fall off the narrower ends- just a security so to speak.
I'm not one for chains usually, but on rocks the ability to shorten and lengthen, plus the fact that they can't be eaten up like nylons. You can also pull them back out without the "thimble" or eye of a cable choker catching.
Thanks DD, I didn't even think of bringing along my chains. I rarely use them, and I usually get a heads up, and as I go across the Port scales right at 39,700-39,900 lbs on my rear tandems, I don't pack anything I don't use all the time just to save weight. I'll bring everything I have, including some things not rated for lifting but maybe handy nonetheless, to keep the chains or cables in position. It looks like this week sometime, should be fun, I'll report back how it went.
This thing works really well on rocks up to about 4 ' . But you need two lines. Most of the ones left around are sold as yard art.
I was thinking of your picker when he posted, but its tough to get one, for just one job. I don't think he has two lines either. It sure would be handy though.
Nice looking set up. Is it a Peddinghaus or Mubea ironworker? Welder looks like an SAE300 or SAE400 but could be a SAM? Looks in great shape.
As long everybody is out of the way when picking, Weld up a set of tongs. Here's an idea … Seems like the critical part is the grab tip width, to keep the rock from tipping out.
That grappler would be great, but downsized, as it would eat up a lot of my load chart! I have just a single winch also.... The consensus so far is we will all show up on the appointed day, with every strap, wire rope sling, chain, etc. all three of us involved own, all I really care about is it's understood we're not using my good rigging (at least underneath the boulders, and the subsequent pulling it out) and if we do it'll be replaced with new! Part of that reason on my part is practical, a small part is it doesn't hurt to further my local rep of being picky as hell about my rigging. This, as opposed to my competition, who leaves his slings exposed outside 24/7, has a spreader bar with grade zero hardware store chain WELDED to it, etc., but undercuts me in price. My good customers are sharp enough to understand the difference between us, the ones that don't I don't want anyway, as they are the ones who go broke/don't pay, and are a pain to work with in general. This project is for my town's largest developer, his personal home's landscaping, who I've known for 30 years, so we are all "on the same side", wanting to get 'er done safe and quick as possible. If I did a lot of this type work, I'd for sure fab some kind of gripper picker up.
Yes its a Pedinghaus. The welder is a SAM 400, i have an LN7 feeder that can be run off it but no one ever thinks of running 3/32 wire anymore. The tongs look like a good comprimise to the rock grapple, maybe a bit of shape added to the angle irons might make them even better. I put about 80 man hours into rebuilding the rock grapple and did one job with it,ill probably be lucky to ever use it again but thats how things go.
if the weights aren't too much you might be able to use a demo blanket