Re Arching a 1972 Cozad RGN

[Taylor D]

Hello everyone,

This is my first post, and I'm excited to share my latest project with you all. I recently undertook the task of re-arching a lowboy trailer, and I wanted to share what I learned during the process.

When I first acquired this trailer, I had very little knowledge about lowboys. However, through this project, I've gained valuable insights. The primary motivation behind this endeavor was to ensure that when I loaded my 1997 John Deere 750c dozer onto the trailer, it would be properly supported.

The process began by removing the tires and flipping the trailer over. Upon doing so, I measured and found that one side was completely flat while the other had a 3/8-inch arch. To address this imbalance, I welded strips of 3/8-inch plate, each measuring 5'x20', to the front of the I-beams. Then, with the dozer loaded, I welded the plates using 11018 3/16 rod, applying two passes. This resulted in achieving a 2-inch arch, which was the desired outcome.

After flipping the trailer back over, I installed a new deck and loaded the dozer. I'm pleased to report that when loaded, the lowboy now rides level, meeting the project's objectives.

I hope this information proves helpful to anyone considering re-arching a lowboy trailer.

 

[Taylor D]

 

[Welder Dave]

A lot of times careful placement of heat from a rosebud can give the desired curvature just using the weight of the assembly. Sometimes cooling with water will give more curvature. The curving or straightening is achieved as the heated sections cool off. I've welded a lot of very large skids. After welding they have a bow in them from the welding and cooling. We'd flip the skids upside down with blocks under the 4 corners. Then heat the main lengthwise beams where the major cross beams were welded in. After cooling the skids were flat.

Is the trailer in question made of T1 steel? That's what 11018 is designed for. If the trailer is a lower tensile steel the 11018 may crack. It doesn't have as much ductility as mild steel or lesser xx18 rods like 7018 or 8018 (8018C3). I hope it works out for you. I'd keep an eye on it not only for cracking but because the 3/8" strips are pretty marginal. I'm not familiar with re-arching trailers but normally to strengthen something like a vehicle frame, the rails are boxed in. I'm curious if once the proper curve was established, a strip could be cut to match the curve and then used to box the I beam. It could have the holes in it the same as the original beams.

 

[skyking1]

nice work, thanks for posting.

 

[terex herder]

All the bending strength is in the flanges. Boxing is for torque ridgidity.

 

[cuttin edge]

A lot of times careful placement of heat from a rosebud can give the desired curvature just using the weight of the assembly. Sometimes cooling with water will give more curvature. The curving or straightening is achieved as the heated sections cool off. I've welded a lot of very large skids. After welding they have a bow in them from the welding and cooling. We'd flip the skids upside down with blocks under the 4 corners. Then heat the main lengthwise beams where the major cross beams were welded in. After cooling the skids were flat.

Is the trailer in question made of T1 steel? That's what 11018 is designed for. If the trailer is a lower tensile steel the 11018 may crack. It doesn't have as much ductility as mild steel or lesser xx18 rods like 7018 or 8018 (8018C3). I hope it works out for you. I'd keep an eye on it not only for cracking but because the 3/8" strips are pretty marginal. I'm not familiar with re-arching trailers but normally to strengthen something like a vehicle frame, the rails are boxed in. I'm curious if once the proper curve was established, a strip could be cut to match the curve and then used to box the I beam. It could have the holes in it the same as the original beams.

Speaking of box, he has a nice looking box scraper with a scarifier that would have been handy for your dirt track.

 

[Welder Dave]

I have a landplane and a box scraper I put heavy duty gauge wheels on but the grader makes it smoother a lot faster. The box scraper might work good for touch ups though as the tractor might follow the contour a little better.

 

[cuttin edge]

I have a landplane and a box scraper I put heavy duty gauge wheels on but the grader makes it smoother a lot faster. The box scraper might work good for touch ups though as the tractor might follow the contour a little better.

I like how the scarifier seems hydraulicly adjustable. it looks like it would fit the back of my Mauldin grader.

 

[Welder Dave]

Some box scrapers are fully hydraulic for the scarifier, tilt and cutting angle. They can level pretty good but take a lot of practice. Still not as nice as a grader since the tractor has a short wheelbase.