Thread: Truck Pull

Detoured from the "Damage from accidents !!! " thread...
http://www.arboristsite.com//showthr...&threadid=3611

i use a truck confidentally to pull trees over (sometimes put through a 3/1); sometimes lift limbs-then lower thru a PortaWrap on the hitch; sometimes pretightening a line with the truck, then lower the same way through a PortaWrap. But, i really hear you guys about overdoing it!

That is what i meant by "carefully metered force"; the points about proper timing for its application are very important too. Eye see a truck as one type of portable power and anchor; that can be safely used with discretion. One, point is we never really max out the truck, have it sliding sideways, burning rubber or anything. Just to apply overwhelming force at the right moment. Just like all are ropes are so much stronger than we need, we always keep the RPM's low. So we would have all that force in reserve, if we need it; without wearing out the guys, or possibly with less of them! i look at the truck as a tree-mendous amount of power; that we are only going to use a small metered amount of, with plenty of reserve.

The first thing i look at; is 'how much force do i need?'..... 'How off balance is the tree?'; and then 'how much leverage do i have already?'.

i look at how the weight is distributed in the tree, ie. how much lean am i fighting, and is the weight of lean high or low that i am fighting. i see the point between the cut and the pulling point as a lever. The higher the weight is leaning backwards, the more leverage it has against me; the more force i need. Lower, weight leaning backwards is easy to get leverage on. i look at the attatchment point of the limbs to determine this height/leverage point of that weight, and then subtract equivalent weight leaning forward at its attatchment points; judge what has leverage on what etc. Though a lot of times, we use a truck on things we don't have to. Just when we would like more positive steering and slower drop; by pulling the tree earlier in the backcut; with a 'meatier' hinge, to usher it down. Thereby keeping the tree more 'polite'; on it's fall; into wide facecut. That wide mouth facecut gives the system the mechanical instruction for the tree to hang on longer to the stump; until the faces slam together; committing that all that leveraged, moving force to stop or tear off, as it can't move anymore.

i seek to maximize the leverage into the system by putting the line in the tree as high as possible. i think tracing the line down the back of the tree; instead of just a running bowline up to the top, gives it more bracing; thereby you can confidentally put it into the tree higher, for more leverage. Also, it applies the force in a cocked back position, pushes the tree from the back, and also allows for second guessing your (or someone else's) choice of where it is in the tree. Dropping the cut as low as feasible, also; increases leverage; i like staying in an upright 'running' position - just in case!

i also think that the bend in the red rope at the top; before it comes down to the clove hitch 'wants' to straighten out; the more line tension there is; thus putting some some diffrent kind of force into it too. But, i can't prove or site exactly why.

We also, wedge from the back; using the longest wedge possible. If, a wedge takes a longer distance to give you the same amount of lift; it will put more pressure on the lift of the tree (if your pounding it in tight). Taht's the Mechanical advantage, of that longer distance to achieve; funneled into the same space. A lot depends on the moving machine here, ie. the hinge. So it must be just write. Any rot, 'cat facing', knots, dryness, species, temp etc. that would effect the strength or flexability; could effect the outcome. Good wood, with the face cut almost half way in (scheduling the hinge to be at the widest part of the tree); and walk the hinge down to a point of failure and ease it down with overwhelming force. With the most amount of strong, flexible hinge ushering it down with the most control.

Then, after all else is maximized; we dribble some of the truck force on top at the right moment. Usually a well centered pull, unless we are trying to get some kind of tourqed pull or something. Knowing we could wear the truck out, before we even had enough backut to free it to to fall, might be able to break the rope, mabe even snapping the tree backwards at the same time! We just don't! We just carefully use that mule and anchor and save ourselves, and have more backup force in case something goes wrong! And with a 3/1 on it; you have massive power available; with a lil run; you just very carefully meter it in confidentally, after surveying just what you need when; and realizing you could overdo it at any time, and have plenty of power to get you out of trouble, or into it!.

If I am using a truck to pull over a tree, I use it as an anchor point, period.

I will attach the rope, put presure on the line, set the parking brake, turn off the truck, and remove the keys.

If this is not enough to tip the tree I will piggyback a come along or block and tackle to the pull line. A truck has way too much power and I could discribe many scenerios where bad things happen from applying all this power with a man at the base of the tree being removed.

Here's one:
I picture a 16 year old kid, punching the throttle of a 4 wheel drive one ton, just as some farmer is making a backcut, and the 3/8 nylon rope the got at the farm supply store instantly snapping as the tree swings back and breaks off falling on the farm house, killing his whole family. After moving into an apartment, the farmer so dispondent desides to kill himself by running his truck in the garage of the apartment building. Only he kills a family in the upstairs with the exaust fumes and is rescued before he dies.

A running bowline at the treetop, rather than a rope running through the treetop and down to the base, will give more power to the pull.

Tuesday I felled a pretty massive box elder against a significant lean by tying into the top with a three in one setup with a truck as an anchor point and a tractor side by side as the pulling element. with that combo I had enough even force to raise the tree up like the boom of a crane on its hinge.

The trick was to pretension the line just enough to see the top move so the tree was supported and balanced during the backcut and not wanting to pinch the bar, only when I could produce some movement with a wedge did I step back and signal for pull
I hope you don't use 3/8" hardware store rope with a hot dog teen one ton driver on your crew Mr.Maas

I have been told in the past that when you are pulling a tree over with a truck / tractor / etc that you first make your notch cut (normally 1/3 of the way through) and then put tension on the line. After you have the desired tension you then go and make your cut with a few wedges handy. The reason for this is that what happens if that pull line you have in the tree snaps on you? Where does that leave you as far as pulling power goes? When I was 17, my ex-partner had picked up a nice tree account for us. I remember all kinds of screw ups that we did back then when we were uneducated. 2 situations that come to mind is 1) we put a rope in this little piece of garbage maple tree, put the rope to a block, and back out to one of our trucks. I was in the truck pulling and when my ex-partner went to make the back cut, he barely touched it and the thing went right over (barber chairing I believe) We both were fine luckily. Another time at the same house, we were going to remove a maybe 18" diameter white oak which was only a few feet from the mother's house. We decided to pull that with a truck down in the woods, WHAT A DUMB IDEA! The white oak wound up getting hung up in a red oak and it took us a few hours to get it out of there. What was even worse was that the customer was right there watching us for most of the time.

Does anyone Use a Trunk mounted winch to pull trees? I was considering getting one.

we used to use a winch on the front of our chip truck all the time, it works good to keep tension on the line. like stated earlier when using a truck set the brake and turn the engine off, thats how we use a winch. you can not get a winch fast enough to keep up with a falling tree.

we have recently started using the fiddle block set up from sherril, (1 week). so far we really like it, you have a better idea of how much tension you have on your rope, and you can readjust easily when used with a PWIII. when we were first getting started we learned a valuable lesson of pulling with trucks and tractors, to much room for miscommunication and error and damage.

but back to the winch on the front of the truck, we use it all the time for other thing, such as loading logs on a flatbed, pulling logs up hills, pulling the loader and bucket truck out of mud, very useful.

The GRCS beats all with 12:1 MA you can pull anything with a good hinge over. By using redirrects I have nevr found a situation where I cannot mount it somewhere conveinient.

With the multiple uses it has it will pay for itself in a very short time. As I've said before if it shaves a (very conservative) hour off of each big job then it will pay for it'self in 25 jobs.


John Paul sanborn
GRCS Representative at Large

i beleive that DDM asked about a Trunk mounted winch; i had tried it, but never had luck with my Baileys Capstan Winch; but others of the brethren have. I beleive the response was for a truck mounted winch.

My whole point of this was to set yourself up with maximum leverage and use the truck's power very sparingly; when the hinge was ready to fold. Too have all that truck's power ready to use, to absolutely overwhelm the situation, metering decisively just how much power to get a graceful fold and at the right time.

We all try diffrent things, that makes up or own experience, that might not seem to transfer over or speak the same to another. One of the things i have done a number of times; is to lift huge things up with a 3/1 on a truck. To knotch a piece in the final direction to drop of choice; when all else is impractical ...............UP! We have done this where a crane can't get. So, i have made that knotch at the top of a horizontal limb; walked a backcut from the bottom up to a point failure; then cleared out as a the truck started to pull up then only. So i guess you sharpen yourself up like that, all that timing really comes into practice! Also, lifted trees and huge limbs off a few cars from storms with it!

We don't do it all the time; sometimes not for months, but there is simple ready power and anchor, sitting right there when you need it. We just don't rule it out; and only use as much power slowly as we need it. Knowing we could blow it with too much power; just be surgical! Before the backcut is so far through, there is nothing you can do, except screw up if you pull with all that power on it! So, we might brace the tree; but never pull on it at that point. The driver is someone that doesn't have that radio playing in there head where they can't hear you, and will do what you say and when!

If, you are pulling over a 3' diameter Live Oaks (hope i never have to do that!)with 2 guys on a 3/1; would they figure out not to pull on it with all their hemarroid popping might, right from the time you started the backcut by the 10th tree? That they could only effect useful pull on it till a certain point? It is kinda like that with the truck; only they won't be able to snap the rope, barberchair the tree or catapult it backwards like the truck can. There is so much power there to use so easily, ya just gotta take it easy; and only use what you need, when you need it.

The 12/1 is very well taken though! But still a truck could probably out power that and quicker; especially with a 3/1. Also, when using the truck as an anchor, we chock it and brake it; then turn the wheels in such a way that if it started it to creep, the hitched point would be arcing away from the pull, as an extra locking in position strategy. For sometimes, we do jsut as you say, for we don't rule that out either.

Hey treespyder,

As I wallow in my ignorance I was wondering exactly what a TRUNK winch is? I figured DDM had meant truck winch and made a typo. Explanation would be greatly appreciated.

The Good Rigging Control System is a trunk mounted winch system. You can read all about it at Sherrill's website under "Rigging" then "Lowering Devices" at http://store.wtsherrill.com/HTML/pgi...s,2,157,=,lowr

Other lowering devices exist, but this is only one that allows you to lift logs by using the hand crank. (I'm told the Hobbs does this as well, sorry Mr. Blair!) I have not developed an opinion, but you have to look at your needs and your pocketbook before you buy one.

TreeSpyder: Never in my life have I ever used a truck to pull over a tree, and I never will. The Forestry Industry Safety Training Alliance took me through two levels of their training, and they employ chainsaws, wedges, and axes. I asked about using ropes, and Ken Lalmont said if you were really insecure, you could put a tagline in at the top for extra help.

The point is, you should be able to fell a tree without the use of a truck. If you feel you need a truck, you should re-evaluate what you're doing and seek out alternatives like blocking it down or craning it out. When you torque a hinge so far, you risk snapping it off. The fibers in the center of a tree can be hundreds of years old, and they may respond unpredictably when you place that kind of force on them.

Secondly, <i>you can not "meter" force with a pickup truck.</i> You can meter force with a spring scale. You can meter force with a hydraulic arm. Trucks are made for driving and pulling trailers with their hitches. If tree climbing champs, loggers, and long-time arborists are telling you should not use a truck when felling trees, perhaps it's a good idea not to. I guess that's all I have to say - I just don't want anyone to get hurt or sued.

Nickrosis

Earlier Mike said:
A running bowline at the treetop, rather than a rope running through the treetop and down to the base, will give more power to the pull. [/B][/QUOTE]


Why Mike?
I would have thought that the pull would be doubled at the tree top with this set up ?
KC is this what you mean by a 3:1 ?

**I rescind this post later, but I left it for posterity. I made one note about the math, but TreeSpyder did not mean what I drew.**

A running bowline: TreeSpyder's Technique:


First example: Person standing 100 ft. from the tree, pulling with 100 lbs. of force. Tie-in point for the running bowline is 50 ft. high. The notch is 3 ft. above the ground (round numbers, here folks). The difference between the tie-in point and the notch is therefore 47 feet.

Therefore, theta equals the inverse tangent (tan^-1) of 47/100. Theta (the angle created by the rope in the groundman's hands - if he holds it 3 feet off the ground - and the ground) is 25 degrees. We want to know the <i>horizontal</i> force he creates, so we use the cosine force.

T sin theta = horizontal force; 100 cos 25=90.6 lbs.

Multiply this force by the height of the tie-in point (47 ft). <i>The groundman created 4,258 ft-lbs. of force at the notch.</i>

Second example: A driver wants to equate this force. The rope is tied anywhere in the tree (it doesn't matter) and wrapped around the truck as Daniel described. It last touches the tree 8 feet above the ground - this is where the force is exerted.

To find theta, take the inverse tangent of 5 ft (difference of 8 ft and 3 ft - the notch) divided by 100 ft (distance of the hitch from trunk). Theta is 3 degrees.

I divided the 4,258 ft.-lbs. from the earlier example by 5 feet (effective height of the tie-in point). 851.6 lbs. is the result.

T cos 3=851.6 lbs.

The required force from the truck (T) is 853 lbs.

<b>Think about that!</b> The truck driver has to put 8.53 times (853/100-tensions of the rope) the amount of force on the rope to equate what the groundman does! Need I say anymore? You're putting less stress on your equipment by not wrapping around the trunk. You're able to work with less force and save the rope and reduce the risk of damaging your rope.

I'm still working on the force of when someone falls while climbing above their tie-in point. It'll be another 4 hours before Yale opens for business and is able to provide me with the force absorption capacity of a climbing line per pound. I'll get that to you as soon as I can.

Nickrosis

Nickrosis

Great intent, wrong diagram.

2nd diagram, rope over the top and tied off at the base. (take it from there!)

Graeme

Dang, Nick! Yer pretty smart for a kid. But from looking at your second diagram, it looks like you grabbed the wrong end of the rope! Ya got lots of 'book smarts', though!