tree fell spanning a ditch

[Moosedog6540]

I have several trees that fell in a storm, they fell spanning a ditch, so they are supported at each end, but they are 4-6 foot off the ground in the middle. What is the proper means to drop these safely and without pinching a blade? Thank you.

 

[4seasons]

Two questions first:
1: How much chainsaw experience do you have?
2: How big are these tree? Both diameter and height.

The technique will vary based on the size and how the tree lies. Being able to read how the tree will react to the cut is key to a safe removal. Since you ask this question I would guess that you don't have lots of experience with a saw and would be better off to hook a tractor, truck, or winch to the tree and pull it to somewhere you are comfortable cutting. That of course is not the way I would tackle it, but I grew up on a farm and bought my first chainsaw at 16 years old.

 

[ATpro]

The first thing you have to worry about is spring back from the top or butt end. Sometimes the butt will try to right itself if it's not all the way out of the ground or the root ball is to heavy when the weight of the trunk is relieved to close to the butt. Then there is the spring back problem from the top because of the limbs under pressure. I would start with liming the top first and eliminating that problem then taking a section off at the time from the top. You can work your way back then and once you get in the ditch the tree may get down to a level you can handle better. If not you can still look out for the stump righting itself when you cut it at the butt and be prepared for that. First cut on top and then an offset undercut will help relieve a pinched blade. You can drive a wedge in the top cut and the tree will hinge on that and keep from pinching the blade on the undercut.

 

[Moosedog6540]

Sorry, I should have given a better description. The trees were pretty much dead standing, no root ball or significant limbs to deal with, just a decent sized tree (18-24”), spanning a low spot and touching on both ends. I can’t get the tractor to them to pull, need to cut on site. I have a decent amount of time behind the saw, just have traditionally struggled with this scenario. The wedge from the top makes sense while it is undercut. If I start from one end it will be dropping every cut. Seems like I need to start in the middle to get both sides on the ground, then it becomes easy.

 

[4seasons]

If you are saying start from both sides meaning start at the top, cut to the ditch, then start at the stump and cut to the ditch, then yes, this is good approach.

Now the wedge in the top is for a thru cut from the top. Use a plastic felling wedge, not a metal splitting wedge as it will fall into you chain when you cut thru. The other method is to cut halfway down from the top while watching the gap in the cut for signs of it closing. If it closes it will pinch the bar or grab the top of the chain shoving the saw back at you. As soon as you see the gap narrow, or when you are halfway through, pull your saw out and finish the cut from the bottom. This is assuming of course that you have already released all the stress that the top and bottom are going to have on the bridge by cutting the truck right up to the sides of the ditch.
It is always a pain to get a pinched bar out but sometimes it will damage the bar and chain. But most of the time when it happens to me I just grab one of my other saws and make the next cut to release the pressure. A few times though I have got the second saw pinched also and have to go back to the house for a third saw. Sometimes though it is possible to drive a wedge in the gap with a maul to get a pinched saw out or get enough leverage to lift or roll the trunk to take the pressure off.

 

[CacaoBoy]

Seems like I need to start in the middle to get both sides on the ground, then it becomes easy.

Your first post said "they are 4-6 foot off the ground in the middle." It sounds as if you might find yourself using the chainsaw above head level if you start in the middle -- not a good idea. A photo or two would help.

 

[ATpro]

It only takes a second or two to drive a wedge in, it's good insurance. On something this big you could cut half way through, drive a wedge in, and keep cutting. I use a wedge on the top cut/off-set undercut if I suspect there may be a problem. The off-set undercut creates a hinge affect and the wedge helps control the hinge and keeps the cut from closing up on you if there is back pressure from things like limbs and such. If the tree is already on the ground and the tree isn't big enough to wedge I double cut to make room for the pinch and blade. That is where the old Bow Saw really shined, you could cut right on through. The Bow Blade was tapered on the back and all you had to do is keep feeding it through, pinch or no pinch. When sizing the wood size with the bow size, production is way faster with the bow.

 

[Moosedog6540]

Good stuff, thank you everyone
Eric