Anyone have a clue as to how large a tree a D4 could take down?
That depends a lot on the type of tree and the operator. It could take down a pretty big oak or other hardwood (no big taproot) by cutting the roots with the corner of the blade and ramping up to get a higher point to push. This could take an hour where a D8 would take it down in 10 seconds. 12 inch or smaller should come out without a lot a work.
A large pine would be a lot tougher because of the taproot.
Around here a D6 is usually the smallest dozer used for clearing.
That's just my opinion.
James
I realigned a logging spur not too long back using a hi-trak D4. Not a super strong machine, so I would angle the blade and take a carve out of the uphill side root system. Then I would place the blade as high on that same side and start shoving. Generally resulted in a nice slow tip. Trees were average 36" Ponderosa Pine about 150' tall.
Took about 10 minutes per tree, more effort was in bucking and skidding and refilling the hole where the stump/root pulled out.
Key was to pop some of the lateral roots and weaken the uphill root system.
Like JaRo, I was thinking of the D6 as well.
Like all other things, I say it depends.... on the soil and the tree/stump you're trying to take out.
Blade time and operator made a difference. James is right. If you spend the time and cut the roots, you can take a 4' tree down.
However, I've seen trees give 8's and 9's fits, and a Track Hoe walks up and pops it from the top.
I'd think that with not a lot of time, at least a 20" tree could be felled fairly quickly.
The landfill has a two 12's and they are an awesome sight to watch push!
Never ran a high track D4. D4's have many different series down through the years, so the question can't be answered without some restrictions. Our old D4 was built in 1948, has a blade that you can adjust the angle by pulling some pins and pushing the blade to the closest place to what you want and can then get the pins back in. Pushed a lot of dirt with that thing but the short tracks and poor flotation setup made it hard to get an even finish without dragging some material back over it using the back of the blade in soft ground like filling in erosion ditches in hillside fields. The Case we have is equipped with a 6 way blade adjustable from the seat, can even dig a ditch with it using a corner of the blade. Your leaving a hing point and then pushing from the uphill side is probably the safest way if you ease up to the tree with your blade, hitting it with a jar could shake loose a Widow Maker to ruin the day.
jud
I agree an excavator works better. Just dig around the tree to weaken it so you can push it over the direction you want. Some trees you can just grab with the buccket and get it in one dig. A dozer might be better if you are clearing an area of lots of trees. I watched them chain 12,000 acres last fall with two D8's and a 150 long chain between them. They'd take about a 90 foot swath. If the trees got too thick or big they unhook from the chain and push them down with the dozers. These were junipers. I don't think it would work in larger trees like pines.
If I was going into the clearing business I'd buy one of the grinders that you mount on and excavator or for smaller stuff a skidsteer. That way you don't rip up the ground just grind up the wood.
Think of the old song about the ant that moved the rubber tree plant.
Many things are possible. Some are merely uneconomical or take far too long to achieve. A stone wall can be dismantled with a 4-lb sledge, but, I wouldn't want to be the one doing that for a couple of years.
Here's a D4 pushing weeds down:
I would think that a 10" or 12" tree could be pushed down with one if the operator knew what he was doing...anything bigger might be a challenge.
Dynamite or C4 works pretty good on larger trees, but it generally pisses off the neighbors..
Forty three years ago I was helping my dad clear a fence row in order to move some houses from the highway ROW to his subdivision. The most convenient spot was at the corner near a 60" weeping willow. I was unable to get to the heart of that tree with our chainsaw, so I climbed up about 20 feet and wrapped a cable around it. We had a contractor with an IH TD-18 (about equivalent to a CAT D-8) doing the road work. He hooked up to the cable and the best it could do was open it up enough to allow me to get back in with the chainsaw.
Today on an as built survey I saw a newer Cat D-5 that looks no bigger than the older D-3s.
It is most likely cheaper to have the tree cut and grind out the stump.
Paul in PA
Ate lunch yesterday with the local Cat salesman. He was talking about dozer sizes like 6n, 6t, etc. I asked the difference, he said the model numbers have all recently changed, a current 6 can be smaller than a 5 used to be or the same as an older 8, depends on the letter designation.
Fill the D4 with avgas. Drop back about 50 feet. Floor it. You can take down sustantial trees that way. Once.
In 1974 I was laying out a subdivision at Lake O' Pines and the largest white oak I've ever come across was in the middle of a road.
The tree should have been saved because of what it was, but it was a HUD project and everything had to be to spec.
They used a dozer and basically dug the tree up that made a pit that turned into a sink hole for months until they had dumped a good hill worth of rock, broken concrete and other fill to close up the hole.
I've been chased thru the woods by dozers with cutting blades that were taking down entire hardwood forests faster than I could run thru the woods while carrying a transit and my gear. Had to take a 90 away from the dozers.
So, it all depends upon the machine, the operator and the accessories.
