I wanted to add to this thread now that I've had some time with my grapple (about 3 hours of clearing construction debris). If you are going to purchase a grapple, they are not all the same! Figure out what you are going to do with it first, because jaw design is going to effect how you use it. I purchased my grapple based more one weight rather than shape or design as I didn't want to eat up my lift capacity with a heavy grapple. My grapple is shaped like two short crescent moons that come together. This shape allows it to open WIDE and grab a very large object but the bottom jaw is only lightly curved and when the bucket is in the upmost position, is still curved down enough that nothing will rest on the bottom shelf without it falling out unless the grapple is closed. Given mine is small at only 60" and my tractor is a bit small (
L4701), this may not have been the best choice of design as I'm not going to be picking up cars and car-sized boulders. It is very, very handy from "over the top" as shown in the above post, but I had a huge pile of 3/4 sheet and smaller chip plywood that was water rotted and needed to be cleaned up. Since the lower lip doesn't extend out for a nice deep shelf, or curl high enough to get under, I couldn't get enough of the bottom "lip" under the plywood far enough to get enough grip to pick up the piles. As a result, it wasn't very effective and took me a lot longer to clear the pile. I also tore up the ground pretty bad in attempting to get purchase on the pile as I pushed it forward in each attempt. 3 guys with hands probably could have done it just as fast if not faster... But what's the fun in that? Eventually I got most of it but made a lot of trips with only 1 or two chunks of board. Like I said, 3 guys... Here's what my grapple looks like in its uppermost curl - notice there's no way to stack anything on it as there's no bottom "shelf". I would also add that since uppermost curl is already so far "down", if I curl the bucket all the way under and open the jaws, I can literally scrape the ground like fingernails on a chalkboard without the lower jaw even touching the ground. I'm not sure how I'll use this feature just yet but I suspect I will if I need to break up the ground in front of me. I guess I could use it like a giant rake, but I think that's a bit overkill for the leaf piles. Note that my opening is something like 60":
I did manage to pick up a some concrete chunks, old steel pipe with concrete at the base and piles of old barbed wire and dump them over the top side of the dumpster, however, and that was quite effective so the ability to open wide and clamp down from directly above like a giant claw is effective. Brush piles are also cake with this type of design as stuff falls right out when you open the jaws. If I could go back and do this again, I'd probably try something more like this shape but note it's only a 38 degree opening and for "big stuff" might be an issue:
Bottom line - figure out what you are most likely to do. A large shelf-like bottom jaw may affect the overall opening width quite a bit and may limit your ability to "dig in" from above but if you are going after largish, flattish objects that are hard to get a hold of, you'll need that large bottom "shelf" to get under what you are picking up and give you some leverage to pick it up. Also you may want to open the jaw, stack a bunch of stuff by hand, then climb on the tractor and carry it away. You won't be doing that with my kind of grapple.
Happy grappling.