I have a few miles of old fencing that needs to be removed and some replaced, I have a 850K and 200LC Deeres to use for the removal. Cedar, Mulberries, Boxelder, Hedge trees and posts so thick you can't see the wire. So my question is, Would a root rake be the best way to remove these fences? What about a rake on the excavator, its a 50' reach so could stay back away for safety? Any recommendations on a manufacture? TIA.
50' reach means you have a long reach hoe, so a very weak arm/stick for taking out trees. I'd leave it in the yard. Will you be separating any of the hedge trees to allow someone to cut posts? I don't know what your fence line looks like, but around here a neglected fence line would be about 40' wide, with big trees in the center and progressively getting smaller as it gets closer to the field. Your 850 should be able to take out the trees without problems depending on your level of skill. Ripping will bring up roots 20' away from the tree line. If you tear up your equipment playing in dirt its your fault. Trees just want to kill you.
Stick/Root rakes are usually used after the big trees are on the ground. Using the blade on it's own is best or fitted with a tree pusher. It gives better clearance when the root balls come up under the blade.
Are you worried about the (barbed) wire? I'd try to pull the wire out first or clear beside it so you can see it. Last thing you need is wire wrapping around the sprockets.
With a fence row overgrown with trees you don't pull out the fence wire. It is rusted through in places, grown into trees, buried in dirt, and just plain missing. Its also usually brittle, so the long pieces turn into short pieces easily. You just doze the whole thing into piles and bury it after the bonfire.
It would be hard to remove so need to be careful so it doesn't get entangled and wrapped around machinery. I've found old wire with a flail mower and it's hard to remove. Wrapped around sprockets would be worse than bailer twine.
Wood fences? Barbed wire fences? What kinda fence? Clearing trees? If there is no operator that has done lots of dozer clearing then excavator is best can dig roots and push or pull and swing, high up, lots of leverage. Its all about the operator.
I wouldn't think it's a good idea to use swing to push over tree's. The same way you don't use it when swinging a wrecking ball. Hard on the swing gear.
If you are close to say a fence or building and have to pull it at you, then you had better swing it as you pull, or you and the machine could be clobbered. All operating depends on the conditions and what is needed to accomplish the chore at hand. It takes years of clearing to know how to deal with said situations. Depending on the outfit you work for, the boss likes to see progress happening, if not, then you can end up running a hand shovel instead of the excavator. Just like stump splitting with dozer, I've used swing and coast to knock down small scrub trees, no power into the swing when doing it. Then you can just grab them with the thumb etc. Its called production.
I like to use an excavator to pull the wire, posts, and entangled trees and brush out of the field edge, wad it up a bit and then push the wads to larger piles with dozer. Keeps the inevitable chunks of wire out of the tracks. I try to keep the trees and brush not tangled up in the wire separate, build a good fire with that and then throw the wads of fence and friends on top with an excavator. I've been able to pawn the slightly crispy wads of fence off on one of the local scrapyards if I can burn all the trees out of it.
Of course swing is needed in some situations but it's not good to use it for heavier work.