What causes tractor rollovers?

[Hay Dude]

I pushed it pretty hard today.
38,000lb square baler on a 16* incline had my butt pucker factor on about a 9 out of 10.
Tandems were locked and she was still angling downhill a bit.
If it went, it was a long way down until flat ground.
My biggest fear is the baler “gator rolling” me and tractor.

 

[M59]

I was using heavy equipment for paying my tuition and was driving a tractor when I was sent over to mow a steep hill near a school in the morning. Well, there was heavy dew so it was very wet and I slid down all the way to the bottom, over and over and I wonder how they managed to mow such a hill but I got it done. Well the next morning the assistant asked who had mowed that hill and when I raised my hand he went into a long "lesson" on the dangers of rollovers and how lucky I wasnt killed, and chewed out the one who sent me as he said you can never mow a hill when its wet or early morning, so my first lesson in tractoring..

Gravity combined with either Lack of Experience or Stupid or So Experienced that they push the limits.

 

[M59]

But there is always something that makes it reach the "tipping" point...

The Operator. See post 82

 

[5030]

In all my years of running ag tractors with loaders, I've never had any weight on the back unless I have an implement on but usually, nothing, but then I have common sense too.

 

[rocco611]

lots of good advice in this thread also keep your ROP in the up position, wear your seat belt.

 

[scootr]

If you are working with a FEL on the tractor be aware of how the height of the bucket changes your center of gravity. Also loaded tires decrease the chance of a rollover because they put additional gravity where it does the most good, down low. Which is where that bucket should be on a hill.

 

[Vigo327]

In all my years of running ag tractors with loaders, I've never had any weight on the back unless I have an implement on but usually, nothing, but then I have common sense too.

Seems to me like weight of the tractor goes up quicker than loader capacity, and they probably get more rear-heavy the bigger you go due to the wheels+tires. So there's a non-linear increase in safety factor just from those things the bigger you go. If you include tire fill it's a HUGE, almost exponential rise in safety as the tractors get bigger. For example, just going from a 1 series to a 2 series JD, 1025 vs 2025 etc, the amount of weight the rear tires will hold as fill goes up tremendously, making a tractor that's not much larger or heavier on its own, vastly more capable of safely operating at the limits of the front end loader. My B8200's filled 13.6-16 rear tires are almost holding more fill weight than what the loader on my smaller b6100 can even pick up.

I guess when you get up to a certain size point, cabs become sort of an assumption as well, but just as a point of reference, the cab on the tractor in your avator weighs more than the ENTIRE fel+subframe on my B6100.. cabs aren't ridiculously heavy, but they're not nothing either, and they're in the right place to make a difference.

 

[MHarryE]

Smaller tractors need rear ballast worst. Larger, tractor itself provides counterweight. The Kubota Grand L’s I had (3 of them) seriously needed rear weight. Moving bales, rear spear lift a bale first before thinking of front. M7 I now have, heaviest weight I loaded was a 6,000 pound book spec shop lathe that it easily lifted and was controlled (flat ground) and loaded onto a semi. Steering was very difficult so it was slow going but slow and safe. But my tractor, loader, and ballast is over 20,000 pounds vs. 6,000 - 7,000 range for the Grand L’s. Even my M5-111 at half the weight of the M7 can load bales safely without rear ballast, but you don’t have the comfort feeling of 10 ton tractor.

 

[npalen]

I have not personally tipped a tractor, but the times ive been nervous about it have all involved using the FELs.

Im guessing most people have concerns about slopes ive just never driven on the likes of. One thing I would say is we tend to form our first assumption of how tippy something is from how it looks, but tractors can be deceiving as far as their center of gravity. A lot of times the entire top half and sometimes more than that weighs very little and the actual center of gravity is somewhere vertically around or below the bottom of the frame. You as the operator are way above that so you become extremely sensitive to any sudden roll accelerations just because they are amplified by your long 'radius' from it, but usually get nowhere even close to tipping. You would start falling out of the seat before the tractor itself is in danger of tipping.

It's probably a good thing that things 'feel worse than they are' from the operators station just so that we're subconsciously more cautious.

The design software (ProE) that my company used would give the exact location of center of gravity and it was interesting to see how much a little weight change here or there would move the CG. I suppose it would be a stretch, though, to expect tractor manufacturers to publish this info not to mention all the aftermarket variables that affect the center of gravity.

 

[npalen]

What causes tractor rollovers?​

Tractor Drivers
Someday someone will tell me why people drive around with the bucket raised

I asked that question of a farmer and he said its for improved visibility such as in haying operations. I've seen it a number of times and also wondered why.

 

[npalen]

I've mentioned it before with very little agreement that liquid in tires may increase the chance of a full rollover rather than just a roll to the side.

 

[scootr]

I've mentioned it before with very little agreement that liquid in tires may increase the chance of a full rollover rather than just a roll to the side.

I'm not convinced - do have some data to share?

 

[npalen]

I'm not convinced - do have some data to share?

No data. (LOL) Just a theory that the liquid weight in the tires is going to quickly slosh to the "topside" of the outside tire when the tractor is at 90 degrees in the rollover. Does the liquid weight tend to push the tractor over to 180 degree? Its a bit of a catch22 as one could say that the tractor with weighted tires wouldn't have rolled in the first place.
I don't know, its just speculation.

 

[scootr]

The tires are filled as much as 75%. So the actual slosh factor would be minimized and not sudden in my opinion.
You can test your theory by tipping over a roundish tupperware container (or such) then filling it with some water and repeat.

 

[Vigo327]

I could see an argument that filled tires make it less likely to get any wheels up off the ground in the first place, but shortly after getting any wheels up they're going to make it worse.

My thinking is that by the time the tractor even gets close to an angle that could turn into a rollover, it will usually have momentum to its rotation. At that point the outer/upper filled tire has hundreds of lbs of weight with momentum going in the rollover direction, exacerbated by it being at the greatest distance from the fulcrum/axis about which it is rolling. The inner/lower tire has the same weight but is so close to the fulcrum/axis that the inertia it presents to the rolling motion is not helpful.

It would be a bit like the thing where you hold an axe up in front of you with your hand at the very bottom of the handle and start letting the axe head drop towards your face. If you let it get much momentum you have a hard time not taking axe to the face. Now put on a glove that weighs as much as the axe head... not much help, eh? That would be like what the filled tires are doing once you get some momentum going in the roll direction.

This is still conjecture though. I'm not certain filled tires make it worse.. just can see a plausible argument.

 

[Jstpssng]

^^^^^
By the time it gets to the point you are talking about though, you’re screwed anyways. Consider the amount of extra force it’s going to take to bring those tires past the point of no return to begin with, vs unloaded tires.
My tires are NOT loaded; and I had some serious issues before I bought wheel weights. It still comes up too easily, but nowhere near as bad as it was. I was disking a side hill one day and had to be careful as the rear on the uphill side wouldn’t stay on the ground. That 600 lb harrow on back doesn’t do a thing for weight when it’s not in the air.

 

[Vigo327]

Yeah, i can see arguments both ways and with no personal experience one way or the other i'm just not sure..

But i HAVE noticed that 3pt implements dont help when the 3pt is in float. If it's not in float they do something, but if it is in float a rear tire can come up quite a ways before the 3pt 'bottoms out' and starts to hold you back any.

 

[ROUSTABOUT]

No drives cause most roll overs.

 

[npalen]

No drives cause most roll overs.

What is a “no drives”?

 

[scootr]

What is a “no drives”?

Do liquid tires cause (full) rollovers? And his answer is simply no - drivers cause rollovers.