Frame dumping trailers

[56FordGuy]

I was thinking about this the other day. It seems like a majority of the semi truck 'wagon' trailers are of the frame- dumping variety. Set the trailer brakes, unlatch the tongue, and put the truck in reverse. The hitch of the truck pushes the tongue of the trailer, which is attached to a pivot and causes the trailer to dump.

My question is, why don't we see more pickup truck sized trailers designed this way? It seems like it would be a lot simpler to manufacture than a hydraulic dump trailer. The only issues I can think of are one, the tow vehicle would need to have a trailer brake controller in order to lock up the brakes in order to make it dump. The only other that comes to mind would be tongue weight. Unless the trailer axles were mounted on their own subframe, they would need to be mounted further toward the rear of the trailer to allow it to dump to 45* without the bed of the trailer contacting the ground. When traveling, that would create more tongue weight on the tow vehicle. I suppose it would still work if the trailer bed contacted the ground and picked the axles up while dumping, though it could be tricky if on pavement and the edge of the bed wasn't able to bite into the ground.

What do y'all think?

 

[ccsial]

I was thinking about this the other day. It seems like a majority of the semi truck 'wagon' trailers are of the frame- dumping variety. Set the trailer brakes, unlatch the tongue, and put the truck in reverse. The hitch of the truck pushes the tongue of the trailer, which is attached to a pivot and causes the trailer to dump.

My question is, why don't we see more pickup truck sized trailers designed this way? It seems like it would be a lot simpler to manufacture than a hydraulic dump trailer. The only issues I can think of are one, the tow vehicle would need to have a trailer brake controller in order to lock up the brakes in order to make it dump. The only other that comes to mind would be tongue weight. Unless the trailer axles were mounted on their own subframe, they would need to be mounted further toward the rear of the trailer to allow it to dump to 45* without the bed of the trailer contacting the ground. When traveling, that would create more tongue weight on the tow vehicle. I suppose it would still work if the trailer bed contacted the ground and picked the axles up while dumping, though it could be tricky if on pavement and the edge of the bed wasn't able to bite into the ground.

What do y'all think?

Well I wouldn't want one. I use mine to spread gravel on my trail. Raising the hydraulics while moving with the rear gate chained does a great job of spreading.

 

[powerstroke444e]

I have never seen a non hydraulic dump as you discribed?? Most frameless dumps have a 5 stage hydraulic cylinder. If I am wrong please correct me.

Reason you don't see frameless dumps on light trucks is you need the axles of the dump at the very rear of the trailer and that would be to much tongue weight for light and medium duty trucks.

 

[wdchyd]

I made two of these 5 x 8.5' with tilt (no hydraulics)......while backing, the tail of the trailer would bite the ground, wheels would raise off the ground and the trailer bed would raise up almost vertical to dump......works great at the dump......

 

[herringchoker]

wdchyd....Great setup! How do you get the initial lift so that the tail bites the ground.....gravity? Is the pivot point directly above the axle? Or, on second thought, is the pivot ahead of the axle and you just block the wheels and back up?

 

[Diamondpilot]

Tongue weight is a issue and the relative low price of the hydro system make it a no brainier. Hydraulics is safer and much more versatile.

Chris

 

[wdchyd]

wdchyd....Great setup! How do you get the initial lift so that the tail bites the ground.....gravity? Is the pivot point directly above the axle? Or, on second thought, is the pivot ahead of the axle and you just block the wheels and back up?

The frame is 3" channel iron and the rear piece is facing out back leaving the pointed sharp edge to dig in to the ground when backing up......sometimes 4wd is necessary to attain lift but the weight of the material in trailer helps to hold down rear......the pivot is ahead of the axle and the axle is fairly tall (mobile home axles/wheels).......blocking wheels doesn't work cuz the tail of the trailer is the spot to bite.....geometry has to be just right...

The first trailer like this I built was just an accident that it dumped.....

Didn't use hydraulics as we all know it probably would cost too much to send out to repair if it spings a leak.......:laughing::laughing::laughing:

 

[ashdump]

I have never seen a non hydraulic dump as you discribed?? Most frameless dumps have a 5 stage hydraulic cylinder. If I am wrong please correct me.

Reason you don't see frameless dumps on light trucks is you need the axles of the dump at the very rear of the trailer and that would be to much tongue weight for light and medium duty trucks.

Ditto!

I used to pull a frameless. The truck does not go into reverse and "push" the trailer up.
What happens is that the driver sets the trailer brakes and then with the tractor in neutral, brakes off, raises the trailer hydraulically. As the frameless trailer goes up, the tractor is pulled backwards to make up the difference in length while the trailer is upright. This could make it appear as the truck is reversing, but it is just being pulled back. If you look closer, you'll see the hydraulic ram pushing the bed up.

 

[Raspy]

wdchyd,

That is a nice setup. Do you release a hold down in front that allows the pivot to tilt the bed to the ground initially. And then back up?

It looks like, after you dump, you must have to pull the box back down after pulling forward a bit. Right?

 

[wdchyd]

Yes, I had a latch that would snap in and later changed it to a nut/bolt to minimize rattling going down the road ,most time using trailer I don't use for dumping, just hauling......

 

[Raspy]

It looks like the pivot points are approximately even with the front spring pins. Are you careful to load the trailer for dumping balance?

 

[wdchyd]

After taking off the retainer nuts (to tilt)....I tilt to ground and gravity takes over (balance is important)......the pivot pins raise up when tail is on the ground..... it's all in the geometry and this would not work with small wheels/short axle or long bed.......

The other consideration is the pivot pins could be moved forward (didn't have to) if dumping is too tough to accomplish......this would increase the angle when the tail is on the ground....

 

[QRTRHRS]

I was thinking about this the other day. It seems like a majority of the semi truck 'wagon' trailers are of the frame- dumping variety. Set the trailer brakes, unlatch the tongue, and put the truck in reverse. The hitch of the truck pushes the tongue of the trailer, which is attached to a pivot and causes the trailer to dump.

My question is, why don't we see more pickup truck sized trailers designed this way? It seems like it would be a lot simpler to manufacture than a hydraulic dump trailer. The only issues I can think of are one, the tow vehicle would need to have a trailer brake controller in order to lock up the brakes in order to make it dump. The only other that comes to mind would be tongue weight. Unless the trailer axles were mounted on their own subframe, they would need to be mounted further toward the rear of the trailer to allow it to dump to 45* without the bed of the trailer contacting the ground. When traveling, that would create more tongue weight on the tow vehicle. I suppose it would still work if the trailer bed contacted the ground and picked the axles up while dumping, though it could be tricky if on pavement and the edge of the bed wasn't able to bite into the ground.

What do y'all think?

Truss trailers sort of work like this. The kingpin is on a big baseplate with hydraulics that raise the front of the trailer up maybe four or five feet or so. The trailer wheels and suspension are pinned to the trailer frame somewhat like a standard trailer. Pull the pin then back the trailer up with the stationary suspension staying put allows the trailer to drop to the ground. They have big rollers on the rear of the trailer and rollers spaced out every so often on the trailer deck. Release the deck rollers, the load rolls off somewhat then you pull forward to pull the trailer out from under the load.

This all sounds good in theory but in practice can get pretty interesting. Sometimes the load won't slide so you have to gun it a bit going back. Occasionally, the back of the truck tractor ends up off the ground.

 

[Duffster]

Truss trailers sort of work like this. The kingpin is on a big baseplate with hydraulics that raise the front of the trailer up maybe four or five feet or so. The trailer wheels and suspension are pinned to the trailer frame somewhat like a standard trailer. Pull the pin then back the trailer up with the stationary suspension staying put allows the trailer to drop to the ground. They have big rollers on the rear of the trailer and rollers spaced out every so often on the trailer deck. Release the deck rollers, the load rolls off somewhat then you pull forward to pull the trailer out from under the load.

This all sounds good in theory but in practice can get pretty interesting. Sometimes the load won't slide so you have to gun it a bit going back. Occasionally, the back of the truck tractor ends up off the ground.

You have been there and done that. LOL

Sometimes roller trailers work best in "theory".

 

[QRTRHRS]

You have been there and done that. LOL

Sometimes roller trailers work best in "theory".

LOL! Yeah, gotta love it when you get about three or four feet of air under the rear tractor wheels. Good thing kingpins are super strong!

 

[chopped]

YouTube - Poopy video of frameless dump trailer dumping

http://www.youtube.com/watch?v=lLEMZTu0CO0&feature=related