Need some design help

[bgott]

Would something like an old joedog or jiflock with a wrecker sling and an electric winch powered off the towed vehicle work?

 

[Anonymous Poster]

Naw Gary, no diagram, all I got is a bunch of pretty colored magic markers. I was hopein somebody with a CAD program might fill in the lines in the coloring book.

Another thought that occurs to me, you might want to check with your insurance carrier to see if the deal would be conered. In NY, when you back under a trailer the tractor is insured by the trailer. The state DOT boys frown mightily on the Sooner Boomers for towing cause the towing tractor isn't really insured.
This whole deal would be a lot easier if you just use a chase car with a manual transmission and a conventional tow bar.

 

[Gary_in_Indiana]

That's a good point regarding the insurance and my insurance agent has assured me I'm OK with towing MY vehicles on MY equipment (dolly or trailer) behind MY vehicle. While typically those situations involve towing a trailer or dolly to pick up something I've bought then towing the newly purchase vehicle back I can't see where it would matter which is towing which.

As to using a manual transmission tow vehicle with a tow bar I'd still have to attach the tow bar to something which would still involve getting some attachment point established on the semi.

 

[Gary_in_Indiana]

Bgott,

I'm not familiar with how those work. Would that preclude me from using different chase vehicles?

 

[bgott]

Both of those were converters used to convert a two axle tractor to a three axle. The joedog was basically a converter dolly with a fifth wheel on it and a fifth wheel pin. Clear as mud, right? It would swing when you went around a corner. The jiflock (sp?) was a system, it had sockets that went on the ends of the frame rails that the dolly butted into to keep it from swinging. I'm originally from California, I don't know what they called them in the east. I figure you could convert one if you could find it or build something along those lines and rig it for a gooseneck pole for when it was behind the tow vehicle. You would be limited to a gooseneck equipped tow vehicle. Unless you put a regular hitch on the end and then used a tongue jack that would lift it high enough to back the tractor under. I know people that use a sling set up on an axle with a regular trailer tongue all day long around here to haul cars, all you would be doing is adding an extention to be able to hook it on the fifth wheel. I know one guy who's sling rig might be available for pictures sometime next week. It's, shall we say, lacking polish but would give us a start on designing something.

 

[Gary_in_Indiana]

Harv,

I don't think it's me so much as the different manufacturers and different configurations making this difficult, honestly. /w3tcompact/icons/shocked.gif

Today I went out to North American/Allied/Global Van Lines headquarters here and looked at a number of different year/make/model trucks there at their tractor shop facility. The most common thing was the lack of a common design. On almost every truck I saw a way to make something for the frame rails that would work. Unfortunately, I didn't see a way to make anything that would work on all of them other than a fifth wheel tongue assembly. /w3tcompact/icons/hmm.gif

The frame rail attachment that would work on one wouldn't on the next. What would work on that one wouldn't work on the last one, etc. While there is a commonality of the frame rails there is no commonality as to what is attached where on those frame rails. /w3tcompact/icons/crazy.gif

There are air bags, lights, wiring, bolts, etc., that can interfere with the connection points on the flange I would need to use a flange attachment hitch. I never fully appreciated all the different configurations of equipment until I started on this quest. /w3tcompact/icons/shocked.gif

It looks like I may have to go with the fifth wheel tongue assembly back to a ball mount in order to have something that'll work with everything. If I do, I'm concerned with the 90 degree drop down piece at the back end of the fifth wheel tongue folding under during an emergency stop. What size tubing and sidewalls should I use for this? Should the 90 degree corners be mitered or butt jointed? Is there anything else I should consider?

I spoke to a buddy of mine in Chicago who told me he's seen some type of hitch assemblies either clamped or chained onto the semi tractors being delivered to his store there that tow cars behind for the driver's return trip. He's going to get me some pictures of different ones as they come in for deliveries. Maybe I'm just more concerned with being extra safe and that's the problem. /w3tcompact/icons/wink.gif

Thanks for all your input and advice on this. /w3tcompact/icons/smile.gif

 

[bgott]

http://www.grantgoreandsons.com/item5.htm

The website above has a picture that can be used as a starting point for what I'm trying to explain. Lose the second axle, go with smaller wheels and tires, add a ball hitch or gooseneck post on the hitch end past the pin and then add a wrecker sling to what's left.

 

[Gary_in_Indiana]

What you're describing would essentially be a fifth wheel tow dolly. I'm sure it would work but am really not interested in (spelled 'capable of') building a fifth wheel dolly from scratch. I already have one dolly so I don't really want to build another one, either.

 

[hazmat]

Gary,

Looks like I may be a bit busier at work today so the pretty pictures will have to wait.

As far as the 90 degree corner buckling under braking, I would gusset the corner. Simply weld a triangular plate on each side. This makes a HUGE difference as far as strength is concerned.

Mitred gives you more length of weld, but the "but" joint is simpler to construct. With the gusset, you will have plenty more space to weld.

 

[Gary_in_Indiana]

Will 2" square tubing with 1/4" walls be heavy enough to handle what I'm looking to do here? I know I'd have to use 2 1/2" tubing for the 'over' portion of the sliding extensions and then drill, right? Also, how much do I need to leave in the tube at maximum extension to maintain strength and stability? Lastly (well, we can hope /w3tcompact/icons/smile.gif ), what size and how many (one or two) pins should I use to secure the extensions?