Near Back-Flip when Plowing

[Bob_Young]

This happened a few years ago and did not result in an overturn, but it did raise a couple of questions.

I was plowing with the Ford 4000 and had a 2x14 bottom plow on the 3PH. At the time I was near the edge of the field, going up a slight grade and passing a big maple tree. Suddenly the front of the tractor shot about 4 ft. up in the air. Quickly punched the clutch and everything returned to an even keel. I had snagged a big tree root. Lifted the plow over it and went on.

I was amazed at how fast the front of the tractor went up. I was not going that fast and the speed at which it rose seemed out of all proportion. So the questions are:

1. The 4000 has Draft Control (which I've never bothered learning how to use). DC supposedly raises the implement when it encounters tough going. Could the Draft Control have contributed to the rapid rise by trying to raise the plow?

2. Could the tractor have gone over if I'd missed the clutch or been less alert? I kinda think the implement would've stopped it at some point but if it managed to get to 90 degrees, all bets would've been off.

3. I've never heard of a tractor back flipping when plowing. Has anyone else? Does it point to a problem with my 3PH geometry or plow setup? The lower lift arms are attached BELOW the tractor axles.

I tend to believe that the Draft Control was the sole cause of this incident (other than the tree root, of course).

Thanks.
Bob

 

[Farmwithjunk]

This happened a few years ago and did not result in an overturn, but it did raise a couple of questions.

I was plowing with the Ford 4000 and had a 2x14 bottom plow on the 3PH. At the time I was near the edge of the field, going up a slight grade and passing a big maple tree. Suddenly the front of the tractor shot about 4 ft. up in the air. Quickly punched the clutch and everything returned to an even keel. I had snagged a big tree root. Lifted the plow over it and went on.

I was amazed at how fast the front of the tractor went up. I was not going that fast and the speed at which it rose seemed out of all proportion. So the questions are:

1. The 4000 has Draft Control (which I've never bothered learning how to use). DC supposedly raises the implement when it encounters tough going. Could the Draft Control have contributed to the rapid rise by trying to raise the plow?

2. Could the tractor have gone over if I'd missed the clutch or been less alert? I kinda think the implement would've stopped it at some point but if it managed to get to 90 degrees, all bets would've been off.

3. I've never heard of a tractor back flipping when plowing. Has anyone else? Does it point to a problem with my 3PH geometry or plow setup? The lower lift arms are attached BELOW the tractor axles.

I tend to believe that the Draft Control was the sole cause of this incident (other than the tree root, of course).

Thanks.
Bob

In the situation you described, the tractor's front end would have raised off the ground, draft control or position control either one holding the plow at desired depth. I doubt there was much of a chance of flipping completely backwards either, although, having done that exact same thing a time or two over the years, I'm sure it gave you quite a thrill.

Best prevention would be trip beam plows.

Draft control doesn't raise an implement a great deal. It makes slight and gradual adjustments to keep the implement at a pre-set depth (draft)

Another "effect" from striking tree roots while plowing without a trip plow is to get your chest slammed into the steering wheel. BTDT too.

 

[radman1]

I think the possibilty of flipping backward is nearly 0. The plow attached to the 3 point won't allow it. Raising that high could potentially throw you unexpectedly off the back. I am surprised it could even lift that high unless the draft was raising the 3 point lift arms to the up position which is probably what happened. You hit the root, the draft activated, the lift arms raised and then provided more traction to the tires since the plow was hooked on the root and could raise the front end. Your tires are still driving the tractor forward and you have plenty of hp with the size of tractor to easily lift the front end. Perfect scenerio for what just happened. You may be better off, if the draft wasn't working and then the tractor would just stop and spin, or kill the engine.

 

[Renze]

Re your 3pt geometry: Can you put the plough even close to 90° up when the 3pt lift is in upper position ? I bet not. So even if the slack in the 3pt pins allow for some extra lift, you could never flip your tractor over using a 3pt hitch implement.

What probably happened is that the plough slid under the root, and instead of the plough share lifting the soil up and turning it over, the immovable soil (with tree root) pushed the ploughshare down.

I cut some big oak roots with a subsoiler this way, pulling the front end of the tractor up in the sky several times, so that the subsoiler leg applies full fritction to the tree root, so eventually after some 3 attempts it will snap.

 

[California]

Seems to me if the upper link is not in a perfectly straight line, say if the implement snagged an outer corner, then that upper link might fold when compressed lengthwise. It's better than nothing but I don't think it makes the tractor rollover proof.

Don't most plows have a trip release to deal with roots?

 

[Soundguy]

This happened a few years ago and did not result in an overturn, but it did raise a couple of questions.

I was plowing with the Ford 4000 and had a 2x14 bottom plow on the 3PH. At the time I was near the edge of the field, going up a slight grade and passing a big maple tree. Suddenly the front of the tractor shot about 4 ft. up in the air. Quickly punched the clutch and everything returned to an even keel. I had snagged a big tree root. Lifted the plow over it and went on.

I was amazed at how fast the front of the tractor went up. I was not going that fast and the speed at which it rose seemed out of all proportion. So the questions are:

See how fast your back tires spin? Imagine if they stopped spinning and the axle rotated around them.. pretty fast huh? that's what you did.

1. The 4000 has Draft Control (which I've never bothered learning how to use). DC supposedly raises the implement when it encounters tough going. Could the Draft Control have contributed to the rapid rise by trying to raise the plow?

If you plow much.. you would be doing yourself a favor to lear to use the draft control. And no.. the draft control didn't help cause your accident.

2. Could the tractor have gone over if I'd missed the clutch or been less alert? I kinda think the implement would've stopped it at some point but if it managed to get to 90 degrees, all bets would've been off.

More than likely.. the implement on back would have kept you from going al the way over / getting the 90' straight up mark due to the 3pt geometry.. that would in effect cause a stall of climb due to loss of traction at the rear tires. There could be agravating circumstances like a tire giving out.. rim coming off.. implement or 3rd link breaking, or a side hill that may influence the situation.. but in generaly.. you probably had some degree of safety.. though not nearly 100%.. etc..

3. I've never heard of a tractor back flipping when plowing. Has anyone else? Does it point to a problem with my 3PH geometry or plow setup? The lower lift arms are attached BELOW the tractor axles.

Uh.. no.. the 3pt hitch geometry is a time tested designe used in some variation by pretty much all tractors under 150 hp..

I tend to believe that the Draft Control was the sole cause of this incident (other than the tree root, of course).

Uh.. the tree rot that you struck with the plow was the sole cause of this incedent... draft control had -VERY- little to do with it... Had you been in position control.. it would have done the -VERY SAME- thing... don't blame circumstances on the drft sensing hyds..

As FWJ mentioned.. trip plows are good if you have burried treasure..

Soundguy

 

[Soundguy]

Seems to me if the upper link is not in a perfectly straight line, say if the implement snagged an outer corner, then that upper link might fold when compressed lengthwise. It's better than nothing but I don't think it makes the tractor rollover proof.

Remember.. the third link has swivel ends.. if the 3rd link isn't inline with the toplink connection and the implement.. i'd gues sthat the connection points may get some side stresses.. but the third link istelf should be just as strong. Ideally.. the tractor will not come up enough, due to 3pt geometry and the implement. that the third link isn't holding back tractor weight.. but metrely holding against traction o f the tires to the ground.. etc..

I don't think anyone claims it makes the tractor roll over proof... it merely 'helps'..

Don't most plows have a trip release to deal with roots?

Trip plows do..

Soundguy

 

[Soundguy]

Highly doubtfull that the lack of draft control would have helped any..... the 3pt has no down pressure. IE.. when the root was hooked.. the tractor nose was going to come up as long as the tires are spinning, as the 3pt is able to freely rotate up.. again.. there is no 3pt downpressure.. etc. Position control would have done the very same thing..

Sundguy

You may be better off, if the draft wasn't working and then the tractor would just stop and spin, or kill the engine.

 

[Farmwithjunk]

Highly doubtfull that the lack of draft control would have helped any..... the 3pt has no down pressure. IE.. when the root was hooked.. the tractor nose was going to come up as long as the tires are spinning, as the 3pt is able to freely rotate up.. again.. there is no 3pt downpressure.. etc. Position control would have done the very same thing..

Sundguy

Absolutely correct! In fact, using position control with a plow would GUARANTEE the same results,where-as some draft control systems might have prevented the front end from climbing to the sky. Draft control, on some tractors, has as a built in saftey feature, what is essentially an "over-load" in the system. In particular, the 100 series Massey Fergusons (which I'm most familiar with) will basically "drop" the implement when you strike that "immovable object" resulting in the drive wheels spinning out. The function of that built in "saftey net" is adjustable by what MF calls the "draft bump-stop screw". (Actually a hex bolt, located on the under-side of the rear lift cover) There's a brief milli-second delay in reaction time though. A trip beam plow will simply trip. Solid beam plows will send you chest first into the steering wheel. But the end result would be wheel spin instead of front wheels high in the air.

The effect of a plow hitting something that solid is very much like a jet fighter hitting the arrestor cable on an aircraft carrier. It's a quick but violent reaction at the very best. With the arc shape of a plow, sometimes that arresting motion is re-directed downward on the plow. (which would try to make the tractor rotate around the rear axle, raising the front end) With the MF draft control's saftey in place, that energy would still result in wheel spin. Apparently not all brands/models used that technology.

Draft control, as originally designed by Harry Ferguson was intended to make a smaller tractor more productive. As time (and the horsepower wars) went along, draft control evolved into a form workable on larger tractors and with larger implements. The geometry of Fergusons original hitch still worked, but no doubt was a compromise from its original intent.

 

[Renze]

If the front end had the slightest intention to come up, the top link would have compressed, causing the Ferguson system valve to drop the plough.

In practice, the situation would occur before the hydraulics had a chance to react, but theoretically the Ferguson system would have prevented this from happening.

I used the top link sensing draft on our Zetor 5245 just once: The result was that the plough was lifted out of the ore banks lightening the engine load, as it was only skimming some cultivated soil on top of the hard pan, and lugging the tractor down in the loose soil because it took a bigger bite.
because a 3.5 ton Zetor is a different workhorse than a 1400 kg MF 35, i dont need draft sensing to limit the strain on the driveline, and i try to break the ore hard pan as deep as possible, as long as i dont bring up beach sand.
I plough with a 16" 3 furrow reversible, at 10 inches in light soil and about 12 to 13" in the aforementioned ore hard pan soil.