Converting flatbed to dozer ramp bed

[Junkyard]

I'm not sure what you have in mind for the side rails but unless they're big I think you will fold that last couple feet of the tail like a can if you load something without the support of your ramps. Having cut the beam to a taper instead of the entire beam being angled and tied in at the start of the drop at the desired angle there has been a significant amount of strength removed. If you crawled up to it, got the machine started up on it I suspect that at some point the majority of the machine's weight will be point loaded right on that end. If you've done any stress calculations the one that always yields the highest number is load centered from the points of support. Well when that machine leaves the ground and is just on the tail now it's cantilevered off that tail and now you will have even more than a point load. I understand the design feature as far as ground clearance for the tail, being as light as possible etc but to me it looks like a possible failure point. All the work looks excellent I've just seen a lot of dovetails folded like a lawn chair. The point at which the tail angles down looks well built to me I doubt you'll see an issue there. Sure hate to see all that hard work done and have you arrive at a failure. It's a lot easier to fix now while it's raw steel and easy to get to. Perhaps a fish plate or box that part in?

Looks great all around to me.

Junkyard

 

[treemuncher]

Bear in mind that I am still not done with this project. I have more supports to weld in to stiffen the main frame above the rails. After that, I have 8" C channel sides to weld in....and a top deck to install....and ramps to build...and finish the fuel tank and headache rack. I have more support to add to the beavertail but it is calculated to hold as is without other supports. I was a mechanical engineer in another time in my life but I could not stand life behind a desk - had to go back and re-study to do the calcs to make sure everything was right. I always overbuild and weld on more bead than I should.

 

[Willie B]

Driving a steel tracked crawler up a steep ramp is unnerving. As I have a steep hill to go up, I prefer to carry my 7 metric ton crawler on the truck, instead of the trailer. I have loading docks for this purpose. Even on level ground the risk of slipping on a smooth steel truck bed I use rubber cattle mats from Tractor Supply.

Willie

 

[Willie B]

Unless you incorporate a good system to prevent it, your ramp will risk slipping. My trailer deck is lower than three feet. Ramps are still pretty steep. My ramps are channel stringers, with angle "rungs". The rungs are recessed to keep rubber tires between stringers. Dozer tracks don't touch the rungs, only the stringers. Either direction I go, it raises my heart rate dramatically! I prefer a loading dock.

Willie

 

[treemuncher]

After sliding my PC200 excavator off of a former lowboy trailer, sideways, while I was climbing over the tires on my old 50 deep-well lowboy, I am always cautious when loading & unloading all equipment. After sliding it off, I had to back up and take another run at it in exactly the same place as I did not have any other options on that load out site. My preference is for nothing less than a NGB detach after that incident.

I load and unload constantly with my smallest machine and a 12 ton trailer. I will be copying some of that design and adding in some other precautionary measures to prevent another slide off like happened with the excavator. So far, I've never had any problems with the tag trailer even in some really bad situations. Experience helps a lot, too. I've been at this long enough to learn from others' mistakes as well.

 

[79star]

Looks good. Are those 6" channels with a 18" spacing?

 

[treemuncher]

79Star, my cross members are 6" channel mostly on 16" centers. The tail cross beam is a 6" wide flange and there are also a couple of strategically placed 6" S beams. Tire locations mess up perfect spacing on centers. Side beams are 8" channel.

Here are a couple of more pics of the current progress on the project.

 

[Planedriver]

I have always thought a truck like you are building would be handy to have. Are you planning to put a winch on it?

 

[redneckracin]

Hey , ah, I need to get some "groceries" this week! Can I borrow the truck? Looks like a great build so far! Make sure you put lots of lights, storage, and power fold up ramps! A pto winch would be sweet at well!

 

[treemuncher]

A winch and hydraulics will come later as finances allow. I'm stretched to the limits right now so I have to stick to basics until I get things back to working and bringing in the green. Fuel tank, air powered grease gun and some basic tool storage are in the bare basics category, along with LED lighting.

 

[Willie B]

I really love it. Put a steel deck on it. I used planks the first time. It lasted ten years, and damaged the two layer truck frame. Everything below stayed wet all the time. Mine is a single axle (see avatar). Mine has all the ribs running lengthwise. It's a dump truck. I didn't want the valleys in the decking to prevent dirt from sliding out. Then cover your ramp, at least temporarily with rubber cattle mats, tire tread, conveyor belting, or snowmobile tracks to give your steel tracks an opportunity to grip.

Willie

 

[79star]

Looks great! Keep us updated

 

[treemuncher]

I wanted stake pockets on the bed and I wanted to use them as tie down points. However, I did not want to lose surface area to an outer rub rail with pockets. So, I came up with a better idea for stake pocket tie downs that allow for much more weld surface and a stronger tie down point. The chain is dropped down through the stake pocket and the grab hook is latched into the side of the 6" channel piece. Lots more weld surface than a large d-ring style tie down for a stronger anchor point. Stake pockets can still be used for sides or for tie down points.

Bed has been primer coated, lights cut out and ready for finish coat of paint, then decking. Ramps and fuel tank still need to be installed. Currently cutting and machining the hinges for the ramps.

 

[old-iron-habit]

Looking better every time you update us. Thanks for keeping us up to date. Better make sure you lock it up.

 

[treemuncher]

Getting ready for another coat of red on the side rails. Ready to finish decking once paint is dried and then finish up the ramps. 1st ramp linkage layout has been designed. Patterns made for the plasma cutter keep things moving quickly and identically. Machining plates is usually done 4 at a time while tack welded together to make them stay true.

 

[Willie B]

I hope that isn't pressure treated lumber. It is terribly corrosive to metals.

Willie

 

[treemuncher]

I wish that I had that information earlier. It is treated. I was thinking that the softer wood would be better for track grip. I've done a little research and you are correct that treated it is a poor choice. At least the beams are well painted prior to coverage. I will have to source some white or post oak from a local sawmill.

 

[Willie B]

11 years ago I cut Red oak, had it sawed to 2-1/4". I cut enough to replace it when it rotted. The building It was in was severely damaged in Hurricane Irene in 2011. My replacement bed lumber mostly ended up in Lake Champlain I presume.

Last winter, I switched to steel. As the outer rails were set 1-1/2" higher than the rest of the frame, I added 1-1/2 x 1/4" flat stock on edge running lengthwise. Welding the ribs in was admittedly boring work. I got one piece of 3/16" mild to make the deck. I should have done that in the first place. Parked, it keeps the frame dry. Mine is a two layer frame, and corrosion is a big concern.

Steel weighs less, dumps more easily, and fines don't sift through it. All told, it wasn't any more expensive.

 

[td25c]

[ATTAC

I wish that I had that information earlier. It is treated. I was thinking that the softer wood would be better for track grip. I've done a little research and you are correct that treated it is a poor choice. At least the beams are well painted prior to coverage. I will have to source some white or post oak from a local sawmill.

Nice work on the dozer bed treemuncher !

Myself would not worry about the treated deck floor . This must be some kind of internet anomaly about using treated lumber on a truck or trailer ?
We have used treated wood on all kinds of beds & trailers and no problem ?
Might see some surface rust but nothing compared to salt off the road used in northern states during winter time .
Don't think you have anything to worry about in Tennessee

Dump bed on the C 60 was steel frame with treated tongue & groove lumber for floor sides & tailgate .
Use 2 x 8 treated lumber on the lowboy .
Never had a truck or trailer rust apart from using treated lumber yet ?

 

[gtermini]

I've always put strips of roofing felt under the boards on the cross members with no issues, but the climate here's a touch wetter.

greyson