towing a trailer with a tractor

[lostcause]

i'm wondering what sort of loads you can expect to haul with a tractor and still be reasonably safe. this isn't something i've ever really had a need to consider before, but i have a situation where i am considering building a small dump trailer that can be towed behind my tractor (a jd 770).

this is for a location where you cannot have vehicles, so bringing a dump truck in as needed is out of the question. there are no roads in - virtually everything is brought in by boat / barge. you can bring in vehicles for temporary construction use, but that's not cost effective for repetitive use due to the transportation cost. it's also only a gravel carriage trail road system, so even a full size dump trailer would be out of the question because it would be difficult when meeting other vehicles and pedestrians. you have to watch out for the occasional hikers or bikers along with utvs and golf carts, so you need to be in control of your vehicle.

i'm thinking about a 4' x 6'-6" dump trailer with 15" to 18" sides. i don't have an exact figure on the weight of it yet as it's something i would build as i get to it and as i come across the ideal materials at the right price, but it's bound to be around 1000lb before i am done. i'm planning on a dual axle just to help in balance since my tractor is pretty light. the bare tractor is around 2100lb, and with a loader, operator, and fluids it must be 3000lb or so. a body the size i am looking at would easily hold a yard of materials, and probably a bit more.

can i expect that this would tow fine? my biggest thought would be downhill grades (there aren't many, and they aren't long or extreme) and whether you would experience a case where the trailer starts driving the tractor because of the weight behind you. i'm looking at a 1mph-5mph speed range, and i have the transmission to keep me from freewheeling and gong too fast, but is that enough?

 

[rambler]

Tires on the tractor (ag, industrial, non-grip turfs),

and the surface - wet grass, snow, wet clay,

And 4wd or 2wd and any weight on the rear of the tractor (wheel weights, fluid filled tires),

and do you have a front end loader on the tractor (a negative because it makes the rear end light),

And other such will have great influence on what works and what is dangerous.

I run a farm, drive all sizes of tractors all my life. I got a compact sized tractor with a loader, 4wd, 27hp. pulled an empty 1500lb wagon down the driveway, got onto some dew-covered grass and went for a ride, slide almost sideways on down the hill. Never so out of control on a tractor in all my life. I called the coop that afternoon and they came out in a few days and put fluid in the rear tires. Made it a _much_ more stable tractor. With the loader on, the rear end was too light, and then with the wagon pushing it on the hill made it even lighter, broke all traction when it got on the dewy grass.

Now with the fluid, a much better tractor, works well with 1500lb wagons, and I can pull a full 4000# wagon up the hill - I just think things out & use a bigger tractor going down that hill with a full wagon.

So, I'm not sure you can get a 'real' answer for your question from across the internet. there are so many variables. It comes down to a seat of the pants awareness of what is safe and what isn't.

--->Paul

 

[BelarusBulldog]

If you are making this dump trailer yourself, try using an old camper trailer axle with electric brakes. Cut the axle to the length you need and weld back together. You could use a manual brake controller, or just use a toggle switch and flick off and on, to help slow or stop with. Another way would be finding an axle with hydraulic brakes and buying the brake actuator, coupler.

 

[Diamondpilot]

With that little tractor I would not do it without brakes. Tractor brakes suck....

Chris

 

[Verticaltrx]

I have a B3200 Kubota, which is about the same size/weight as your tractor. As per Kubota, it is rated to tow 3300lbs with 800lbs tongue weight. I have a couple little trailers I pull with it collecting firewood and can attest that it will safely tow that much on all but the steepest hills. I do have ag tires (loaded) which helps a lot for going up or down hills.

I'd shoot for the 3000-3500lb range fully loaded for your trailer, just be sure it has enough tongue weight for good traction.

 

[lostcause]

my initial thoughts were just to use whatever i could find for axles and tires, since i'm looking at less than 1000lbs per wheel - any passenger car tire would be fine, but i may just get a pair of mobile home axles and tires. the percentage of manufactured homes in this state is about 10%, so the axles and tires are abundant and cheap. if i do this i can easily get springs and hardware, along with having brakes if i decide to hook them up. the only downside is the larger tire assembly, though it's not that big of a deal. i had originally thought about electric brakes, though i hope i can get by without them. i guess if i build with them i can test it and see how it feels with different weights. i'm going to be operating on 99% packed gravel, so i hope to have traction.

 

[Renze]

Here in Holland, we do everything with tractors. Tractors are not subjected to road tax, CDL, use dyed diesel which is 2/3 the price of highway diesel, etcetera.

Friday i went with my brother to do a garden in a town about 27km from us. My brother pulled a 10t Veenhuis dumptrailer with a Takeuchi TB125 excavator on the 2nd trailer, i pulled 8 ton of paving bricks and a 6t earth dumper with my own tractor. Both were around 20t GCVW, pulled by a 60 and a 70hp tractor of the early 70's . I took it real easy because i had the dolly axle steered 3 axle trailer, which is a ***** if you dont have trailer brakes, it tends to jackknife because there is no weight on the hitch to put weight on the braked tractor axle.
the 10t dumper of my brother gives around 2.5 to 3t drawbar load, so when not in city traffic or on sloping terrain, you can brake very hard without skidding the tires, even without trailer brakes. But brakes are an absolute necessity when going through hills: You can maintain control downhill with tractor brakes only, but if a car pulls in front of you when going downhill, you dont stand a chance.

However when i parked my "road train" back at the yard, my brother took his 25hp tractor do drive the rearmost 6t dumper to a nearby dumpsite: this trailer used to be an ancient Bedford truck with a communal three sided tipper, so it has its axle too far to the back for a tractor trailer: when dumping the weight shifted beyond the rear axle and lifted the tractor rear end 2 feet off the ground. I had to come resque him with a chain.
So, with tractor dump trailers, make sure you have a sturdy towbar to take weight (for brake performance, as well as traction) which will also mean you have the axle(s) far enough to the back to keep the weight of the upright dumpbody afront of the axle, so it wont lift your rear end before the dirt starts to flow out.

http://www.tractordata.com/farm-tractors/000/1/5/150-john-deere-770.html according to this spec sheet your JD 770 weighs around 800kg. To me that sounds like a single axle dumptrailer with a maximum payload of around 2 ton, with a maximum 350kg drawbar load.


edit: Oh, just make sure the drawbar is attached BELOW the rear axle, or the tractor will backflip if it gets enough traction.

This is a quite common dirt contractors combination in Holland:
http://www.jan-veenhuis.com/foto collage/fotocollage zand/davelaar06.jpg
And these are the biggest they build so far:
http://www.jan-veenhuis.com/foto collage/fotocollage haak/fotocollage_jvha_vierasser02.jpg steered on three of the four axles, with lift axles when driving empty. These are a bit too big actually, with a Deere 8000 or a Magnum pulling it, the combination goes way over the legal max GCVW of 50 ton.

For your application i would build a "Ben Hur battle cart" model, aka wheelbarrow model:
http://www.poppink-reutum.nl/dumperbouw/index.php?p=page&titel=Dumpers enkelas&t=1
Big tractor tires aside the dumpbody make it pulll very light in heavy terrain.

 

[uglyboywith11fingers]

Renze... interesting equipment in those links, not like what's common in North America.
I have a cousin at Ommen, he has similar large machines.

Pete

 

[Renze]

not like what's common in North America.

I heard from cousins in Ontario that dumptruckers were pissed at the Dutch guy in town, who brought himself a pair of Veenhuis dumptrailers (meanwhile Veenhuis has dealers in Canada too) and kept on driving earth over clay when it rained overnight, while the trucks couldnt work that day...

I have a cousin at Ommen, he has similar large machines.

Ommen is about 15km from my place...

 

[oldbones]

I don't know about towing it, other than put as much weight as you're tractor can handle on the hitch to keep weight on the rear tires.
The thing I'm seeing in my mind is when you dump the load. Just make sure you don't have a load that will hang in the trailer past the rear of the trailer axle, lifting the tongue and back of your tractor off the ground. Kinda like a "vertical jackknife" situation. I've seen pictures of that on the net somewhere, and on youtube. I think this all depends on how far above the ground the trailer bed is and how far behind the axle the hinge is.
Just food for thought.