Tractor, Truck or Car - heaviest per square inch?

[Bob_Skurka]

I'm curious because one of my neighbors in raising all sorts of heck with a local farmer about weight issues. The neighbor contends that farm equipement (the real stuff not CUTs and other small tractors) is too heavy to drive on the easement and is causing ruts. Further he says if the easement is paved with asphalt, then the farmer will tear up the asphalt with his equipment.

Now the neighbor uses the easement as his driveway, he has 3 vehicles so it is probably reasonable to guess that at least 1 or 2 of those drive over the easement every day to exit and then again to enter his property. I'd say that 2 ingresses and 2 egresses each day of the year means the guy uses the easement about 1400 to 1500 times each year.

The farmer probably uses the same easement about 20 or 30 times each year (at the most).

The neighbor is blaming the farmer for potholes in the gravel easement. The neighbor wants to pave the easement (which is only 50% on his property) and the neighbor wants other people to pay for the other 50%. Personally I think it sound like an unreasonable thing to ask for from the farmer or anyone else, but I honestly don't know if a 6 wheel truck or a 100hp farm tractor or an 8 row combine put more or less pressure per square inch on the ground that a car or pick up truck do?

Does anyone know the FACTS about this?

 

[Gatorboy]

Well, my 90 HP Kubota weighs 7000 pounds. The back tires are a whole lot wider than the average truck/car tire, and the front tires are probably comparable.

The Ford Excursion weighs in at 6734.

So I would think taking into account entire surface area of the tires in contact with the ground, the Excursion exerts more weight per square inch than a tractor.

Regardless, I don't think the neighbor has a case.

 

[Phil_R]

It is really quite simple to determine which vehicle puts the most pressure per square inch on the road surface... check the tire pressure. If a 2500 lb. car averages 32psi per tire and a 7500 lb. farm tractor averages 12psi... the car is heavier per square inch of contact. (car is 2.66 times as heavy per square inch of contact)

At my place, the 7000 lb. Dodge with 65 lb. pressure loses the heavy-weight title to a small trailer that requires 90 lb. tire pressure at a mere 2000 lb. gross weight.

 

[Bob_Skurka]

Phil, your post seems to agree with Goodyear. I just dug this off their website: <font color="blue"> To assess ground bearing pressure, the tire inflation pressure is the primary factor plus an additional amount that represents the tire casing stiffness when deflected. For bias farm tires, this casing stiffness factor is 2 to 3 psi added to the tire inflation pressure required to carry the load and for radial farm tires, the ground bearing pressure is 1 to 2 psi added to the required tire inflation pressure. This is a far simpler and more accurate technique to assessing ground bearing pressures than any approach using contact area figures as described above. </font>


Now all that said, I have to go back to Gatorboy and the absolute weight of the 2 machines and pose a situation just a bit differently.

If I drive a 10 ton combine over a wooden bridge with tires at 20 psi I might damage a couple wooden deck boards but not collapse the bridge. However if I drive a 20 ton combine over the same wooden bridge and that combine has tires inflated to 12psi, I would not damage the deck boards but I might collapse the bridge.

So what does more harm to the gravel road? Absolute weight or weight PSI?


Gatorboy . . . BTW, I totally agree that they guy doesn't have a leg to stand on, but I'd like to side with the farmer and be able to give him some proof to go with my moral support.

 

[hobbyfarm]

Webster's ease·ment n. Law. A right, such as a right of way, afforded a person to make limited use of another's real property.

One can belly-ache all he wants, but an easement is there to use. I doubt if he can legally do anything to keep someone from using it. Tell your neighbor to quit being a girlie man. /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif

 

[Phil_R]

</font><font color="blue" class="small">( So what does more harm to the gravel road? Absolute weight or weight PSI?)</font>

PSI weight is what harms the gravel road... based on my limited experience accessing load carrying capacity of soil types. (once again in my limited experience, always expressed in PSI, not absolute weight)

 

[Gatorboy]

<font color="blue"> So what does more harm to the gravel road? Absolute weight or weight PSI? </font>

I believe it's absolute weight -- but in terms of weight divided by axles. This is pure speculation -- I am not a structural or civil engineer.

EDIT:

I now want to reconsider. I just remembered that when we go to the Eastern Shore, and want to drive on the sand, we take out air in our truck tires. This lowers the PSI, and enables us to drive on the sand much easier. So, the LOWER PSI must enable the truck to "float" easier across the surface even though the absolute weight of the truck doesn't change. The same must hold true for the pressure put onto a gravel road. The lower PSI, the less damage.

 

[Indydirtfarmer]

</font><font color="blue" class="small">( I'm curious because one of my neighbors in raising all sorts of heck with a local farmer about weight issues. The neighbor contends that farm equipement (the real stuff not CUTs and other small tractors) is too heavy to drive on the easement and is causing ruts. Further he says if the easement is paved with asphalt, then the farmer will tear up the asphalt with his equipment.

Now the neighbor uses the easement as his driveway, he has 3 vehicles so it is probably reasonable to guess that at least 1 or 2 of those drive over the easement every day to exit and then again to enter his property. I'd say that 2 ingresses and 2 egresses each day of the year means the guy uses the easement about 1400 to 1500 times each year.

The farmer probably uses the same easement about 20 or 30 times each year (at the most).

The neighbor is blaming the farmer for potholes in the gravel easement. The neighbor wants to pave the easement (which is only 50% on his property) and the neighbor wants other people to pay for the other 50%. Personally I think it sound like an unreasonable thing to ask for from the farmer or anyone else, but I honestly don't know if a 6 wheel truck or a 100hp farm tractor or an 8 row combine put more or less pressure per square inch on the ground that a car or pick up truck do?

Does anyone know the FACTS about this?

)</font>

Ran into just exactly the same "issue" with a neighbor at a farm we rent 3 years ago. I have been renting the farm for almost 20 years at that point. The owner has farmed for almost 50 years BEFORE I started. We used current "right to farm laws" on the books in Indiana to stop his blocking of an access road THAT DIDN'T even belong to him....

(The farmer in question could wave an olive branch of sorts by agreeing to grade the road once or twice a year. )

Also sounds like someone is trying to get "his" driveway paved for free, or at the very least, for "half price".

 

[Bob_Skurka]

OK we have no consensus (other than my neighbor is a girly man).

So let me re-pose the question a bit differently again. For a gravel road with 1500 transits of HIGH PSI but LOW GVW and 30 transits of LOW PSI but HIGH GVW, what is going to cause more damage to the road each year?

And can it be proved to the satisfaction of a girly man?


INDY . . . you are exactly correct, they guy is out for only one thing, to get someone else to pay for his driveway!

Where would I find out about current "right to farm laws" in Indiana?

 

[Gatorboy]

Bob, notice I added something to my last post. I probably should have just made a NEW post (as I'm doing now) so that it didn't go unnoticed.