pulling force of a B2920

[xring100]

No problem

 

[TomSeller]

You don't need much to guide a falling tree, but you must get it guided at the star of its fall. Have it in a fairly tall gear to keep the rope/chain/cable tight as it goes.

 

[s219]

For tree work with a tractor, I prefer 5/8" or 3/4" Samson logging rope:

Samson Stable Braid Rigging Line, Double Braid Bull Rope

Size depends on the load rating you think you need, and the size of pulleys you're looking at (many handle 5/8 or 3/4 rope). I have a 150' length of 5/8" right now, and it gets frequent use. I use an old gym bag as a stuff sack to prevent tangles.

Rope is often preferable to chain for tree work because of ease of use (guiding through/around branches, other trees, etc) and the ability to tie various knots. Just remember that knots reduce strength. A bowline knot is very handy for logging type of stuff and you can always break t back open even after a high tension pull. You can also splice these types of ropes and put in eyes, with no loss of strength.

Generally, my shackles, links, and pulleys are rated lower than my rope, so they'd end up breaking first. I have a selection of them, and pick accordingly. Also handy is some sort of tree sling. When setting a pulley on an adjacent tree, you want something to safely spread the load.

With a 150' rope and a pulley, I can handle most any tree-work situation and keep the tractor well out of harms way. The ability to reverse direction or change direction of a pull is a big help.

 

[94BULLITT]

I was watching antique tractor pulling on TV one night. The winner was the guy that could pull the most percentage of the tractors weight. Most of the tractors only pulled 75%-80% of their weight. The winner pulled 135% of his weight IIRC. The tractor probably had some stuff done to it to pull that much. I think you would be safe to think your tractor will pull 100% of its weight. When you are looking at ropes, chains etc. look at the WLL, the working load limit. That is what is important. When you use a rope and tie a knot you can loose 35-50% of the ropes strength.

 

[sd455dan]

If your not jerking the chain just a dead pull then you could guesstimate your tractive effort on level ground by knowing the operating weight and mu level Ag tires have about 0.7 mu on hard pack or gravel. Meaning if your rig weighs 4000 lbs you can only pull about 4000 lbs .7 = 2800 lbs is the maximum cable tension you could hope to sustain. However if your jerking it loads go through the roof and i would switch to a snatch strap. As you don't want to be on the receiving end of a broken chain or cable

Might Check the manual -some tractors actually have the tractive force @ a % of slippage listed in the manual, in my Rhinos case it's just over 13,000lbs. @ 15% slippage, and after breaking two 10k (rated straps i don't doubt it)... and the Ford is just over 6500lbs. IIRC from nebraska test data... those #s are with factory weights.

 

[tractchores]

Thanks everyone. I'll check the manual. I ordered some amsteel blue and shackles rated a bit less than the rope. The rope is 1/4" rated at 8k lbs, with a working load of 4k. we'll give it a shot and see how it works. I will probably keep using my heavy chain for rocks and skidding so i have the greater strength and don't tear up the rope. I'll post on how it works out! Are their knots that reduce strength less? I have spliced eyes so will try to use those most of the time.

 

[Gary Fowler]

I don't think you could break a 1/4" chain with a 2920, you just don't have the weight to get the traction. When pulling on a tree with the chain up high, it naturally wants to lift up the tractor also, assuming you are pulling from the drawbar as you should be. I had a 5/16" chain hooked to my 8500# tractor trying to pull out a loaded dump truck a year or so back and pulled the drawbar bracket off the tractor but didn't damage the chain. All four tires had dug holes down over a foot and then started lunging (basically a snatching action)which is what broke the drawbar bracket before I could get my foot on the clutch.
Besides the amount of traction, you don't need much force to guide / pull over a tree when cutting it. Too much force and you may snap the tree trunk which happened to me once trying to pull one out from in the branches of a neighboring tree.

 

[bigdeano]

I did drawbar pull tests a while ago using a hyd cylinder with a pressure gauge. Test was done on damp grass. My 4x4 pickup with all season tires weighs close to 5000# and pulled 3500# when the wheels spun. My 2wd tractor with R1's weighs 6000# with loader and pulled 5250# when it spun. I had the 3ph at 18" off the ground to transfer weight to the rear. The truck tires just spun on the grass, the tractor kicked the sod out the back.

I set up my video camera looking at the gauge to capture the max reading.

 

[94BULLITT]

Thanks everyone. I'll check the manual. I ordered some amsteel blue and shackles rated a bit less than the rope. The rope is 1/4" rated at 8k lbs, with a working load of 4k. we'll give it a shot and see how it works. I will probably keep using my heavy chain for rocks and skidding so i have the greater strength and don't tear up the rope. I'll post on how it works out! Are their knots that reduce strength less? I have spliced eyes so will try to use those most of the time.

Factory spliced roped does not hurt the strength of the rope. Here is some info on knots and how they reduce the strength of ropes. http://www.neropes.com/Resources/sail_reprint.pdf Since you have a nice rope and a chain you may also want to get a tow strap.

 

[tractchores]

I don't think you could break a 1/4" chain with a 2920, you just don't have the weight to get the traction. When pulling on a tree with the chain up high, it naturally wants to lift up the tractor also, assuming you are pulling from the drawbar as you should be. I had a 5/16" chain hooked to my 8500# tractor trying to pull out a loaded dump truck a year or so back and pulled the drawbar bracket off the tractor but didn't damage the chain. All four tires had dug holes down over a foot and then started lunging (basically a snatching action)which is what broke the drawbar bracket before I could get my foot on the clutch.
Besides the amount of traction, you don't need much force to guide / pull over a tree when cutting it. Too much force and you may snap the tree trunk which happened to me once trying to pull one out from in the branches of a neighboring tree.

Interesting. I use 5/16" chain now, so no chance of breaking that. I hadn't considered the breaking strength of the draw bar, I'll have to be careful with any lunging or other jerking type action. The only time I'd be applying full force is the same situation as you mention when a tree is hung up. Definitely need to proceed with caution in those scenarios!

I did drawbar pull tests a while ago using a hyd cylinder with a pressure gauge. Test was done on damp grass. My 4x4 pickup with all season tires weighs close to 5000# and pulled 3500# when the wheels spun. My 2wd tractor with R1's weighs 6000# with loader and pulled 5250# when it spun. I had the 3ph at 18" off the ground to transfer weight to the rear. The truck tires just spun on the grass, the tractor kicked the sod out the back.
I set up my video camera looking at the gauge to capture the max reading.

Very interesting! I'm tempted to try and get a force gauge and do an experiment. I can't imagine that even with 4wd I'm going to be even close to what your tractor pulls given the weight.

Factory spliced roped does not hurt the strength of the rope. Here is some info on knots and how they reduce the strength of ropes. http://www.neropes.com/Resources/sail_reprint.pdf Since you have a nice rope and a chain you may also want to get a tow strap.

thanks I'll check this out. I got a 20k lb tow strap already and have been using it to loop around live trees for the come-along to prevent bark damage. I just ordered some pulleys as well, which will let me stay out of the 'fall line'.