Welding to Medium Towbar? Also, Moving Sea Containers!

nf6x

Feral Engineer
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I'd like to add a trailer tongue jack to my M936A1 wrecker's medium towbar to make it easier to use without Soldier B. Here's my dog checking out my towbar as I test-fit it with a 3D-printed prototype (the yellow thing) of an adapter that I plan to have made to adapt the towbar shackles to the corner casting on a sea container, using clamp-on corner casting couplers:

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The sea container, dog, etc. have nothing to do with my question here. Just pretend you didn't see them. I usually use a farm jack, random junk, etc. to get the lunette up to the right height to hitch to my wrecker, but that's a janky wobbly pain in the butt. So, I plan to add this style of jack near the lunette to make it easier to adjust the height of the towbar for hitching up:

TrailerJack.png

The same style of jack happens to be used on my youngest military trailer, so with some green paint it'll even look right. After hitching up, I can pull the jack off or maybe just swing it out of the way. The round mounting widget needs to be welded on to something, and I plan to gas weld it since a gas welding torch is what I have. I ordered a pair of the jacks... another one's going on the drawbar for my commo shelter mobilizer, which is similarly inconvenient without help from Soldier B.

Now, here's my question: Would it be Very Bad to weld the mount directly onto the towbar, or should I instead weld it to some steel tubing with an ID matching the OD of the towbar's tuning, split that tubing, and clamp it onto the towbar somehow? I'm a total welding noob, and I'm concerned about weakening the towbar. I'll probably never personally use the thing on the road or above a few miles per hour, but I don't want to leave something dangerous for my as-yet-unidentified heirs.

Ok, fine, I know y'all are going to be all kinds of curious about my harebrained scheme for dragging my sea containers to a different spot in my yard. Please tell me if it sounds too crazy. So, I have an M936A1 wrecker, and I have a few 20' sea containers which are gradually subsiding into the ground as the wee bunnies burrow underneath. I want them to be somewhere else, sitting level on some timbers or whatever, with rock underneath to discourage burrowing. I've ordered some widgets that hook onto the bottom corner castings at what we'll call the rear end, with spindles and hubs for 8-bolt rims. I plan to borrow a couple of wheels off one of my decrepit CUCVs, lift the rear end, put on a pair of wheels, and then drag the containers as if I was doing a lifted tow of a deadlined truck. At what we'll call the front end, I should be able to lift the container up with a chain sling and some container lifting lugs, but I still need a way to hook up the towbar. I have a couple of mil surplus clamp-on container couplers, so I designed an adapter to get machined out of steel. I'll need two of them. I 3D printed a prototype to check the fit before I try to have them made, because I bet they won't be cheap. Based on McMaster-Carr pricing, there's a hundred bucks worth of steel in each one before they even land on a milling machine table. What do y'all think?

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And before anybody asks, my dog's name is Anise, and she's a very good girl.
 

runk

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The wheel adapters are cool ! As is your idea for the towbar adapter !
How far and over what terrain are you moving the containers ? Are they full or empty ?
I ask, because I just spent a couple of weekends moving a 40' high cube insulated one around, it was empty with a weight of about 8000 lbs. We were doing it on a smallish urban lot, and the delivery trailer couldn't get it that close to where my buddy wanted it. It was slow going, but not that hard to get it in place with rollers (1.5" schedule 120 steam pipe) boards and a couple of come alongs. We mostly ended up using my small tractor as an anchor point, since there just wasn't enough room to maneuver it for pushing or pulling.

I'm wondering if you aren't overthinking the job ?
With a wrecker and space to operate, I would think it would be pretty easy to just chain up the front of the container and drag it wherever you need it, maybe with some skids under the rear. But, I obviously don't know your distance or terrain.

As for welding on the towbar, there was an MWO for welding the reinforcing collars to all the early ones, and at one point the MWO kits were available. I looked quickly, but can't find the MWO to see if it has any specs for the welding. It would probably be a lot easier to do the weld with stick or MIG.
 

nf6x

Feral Engineer
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The wheel adapters are cool ! As is your idea for the towbar adapter !
Thank you! I hope the wheel adapters actually work... it's too soon to say whether they're brilliant or a bad idea. I'd better set up a video camera. If the container ends up on the ground with a broken-off wheel rolling down the hill, that has to be on video.


How far and over what terrain are you moving the containers ? Are they full or empty ?
They only have to move a hundred feet or so, but not in a straight line. It's dirt, it's not level, and I may have to maneuver them around on rough terrain. They are not empty, and I'd rather not unload them.

I'm wondering if you aren't overthinking the job ?
Oh, I'm certain that I'm overthinking the job! That's how I roll. :mrgreen:

I had considered fabricating some big kludgy thing to adapt my shelter dolly to the sea container corner castings, but decided to come up with something simpler that involves a lot less fabrication. So this overthinking is my version of underthinking!

But anyway, I'll be doing this by myself unless my dog volunteers to be Soldier B. Messing with positioning rollers and also driving the truck would be a big old pain. Getting in and out of the cab or crane gondola to mess with stuff on the ground gets tiring fast. In fact, I'm also planning to put a helper step under the cab step. The first step on my M936A1 is about 30" off the ground, and my out-of-shape >50 year old knees are just done with that. I'm going to try hanging one of these under the cab step. I had wracked my brain forever trying to come up with some grandiose mechanical thing that folds itself up once I'm in the cab... until I saw this simple thing hanging off rubber belting so it can just flop out of the way if it encounters a rock.

With a wrecker and space to operate, I would think it would be pretty easy to just chain up the front of the container and drag it wherever you need it, maybe with some skids under the rear. But, I obviously don't know your distance or terrain.
I have to move them in a somewhat constrained area between a couple of buildings with other stuff in the way, and I don't think I'll be able to avoid maneuvering through some pretty not-level spots to position things. Also, I want to end up setting the containers on some railroad ties or something to support them level with an air gap underneath them, so I think that'll be easier if I move them while everything is on wheels and then lower them down onto whatever they end up resting on. I have a total of 5 acres, but most of it is very not-level. There's about 40 feet of elevation variation within my property boundaries!

As for welding on the towbar, there was an MWO for welding the reinforcing collars to all the early ones, and at one point the MWO kits were available. I looked quickly, but can't find the MWO to see if it has any specs for the welding. It would probably be a lot easier to do the weld with stick or MIG.
My tow bar has some collars around where the pipes weld onto the lunette casting and its pivot, so they may have had that MWO (or maybe they were just later?). That might be a safer spot to weld on the jack since the metal will be a lot thicker, but I'm not sure if the jack would get in the way there while trying to hitch to my wrecker. I'll have to do some experimenting and head-scratching once I get the jacks.

Stick or MIG would probably be easier if I had a welder and knew how to use it. But I don't have one yet, and I've never done arc welding. For that matter, I've only done gas welding once, to reinforce the hitch on my 3/4-ton trailer where it had gotten all tweaked in a previous owner's roll-over! I was thinking that it might finally be time for me to get a stick+TIG machine, but changed my mind and decided to use the torch I already have. I'll get some sort of electric arc welding equipment eventually and teach myself how to use it, but I already have enough projects in the air right now.

Oh, and one more thing: The hoist motor on my wrecker sounds like a metal bucket full of rocks, so I should probably finally get around to pulling the motor off and taking it to a hydraulic motor shop before I start lifting container ends. I hope I don't have a stroke when I see the price tag to rebuild or replace it! I've read that the Army did a Bad Thing when they installed that motor with a pipe plug in the drain port, and that inevitably ruins the seals. I've seen threads recommending plumbing in a drain line from that port back to the tank, and I plan to do that when I reinstall the motor after getting it rebuilt.
 

zebedee

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The welding instructions for the collar "update" to tow bars, include Tempil sticks to ensure correct preheat to the weld zone of the parent material... and with you intending to gas weld - which takes a lot of time or heat to get the weld pool, I'd op for a ID/OD tube idea to clamp the jack leg "bracket" to the towbar tube. (also preserving the integrity/value of the towbar).

(Former AWS CWI so it's not just an opinion incase you are wondering.)
 

nf6x

Feral Engineer
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Thank you! I had a feeling that welding to the towbar without the right level of skill might be a bad idea. I will figure out some sort of clamp-on mount for the jack instead.
 

nf6x

Feral Engineer
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I'm thinking about welding the jack mount to a saddle made by cutting a piece of tubing lengthwise, and then clamping it onto the towbar with one or two vise-grip chain wrenches. But I'm open to suggestions if anybody has a better idea.

I'm still considering how to mount the other jack to the shelter dolly's drawbar. That drawbar is made from 3"x4" rectangular tubing with a bunch of other stuff welded to it such as chain and hose guides. I might make some sort of clamp-on thingy, or I might be able to weld the jack onto one of the bits that are already welded to the main tube without affecting the tube itself.

Edit: For the shelter dolly drawbar, I think I can weld the jack's mount to a piece of steel angle and then clamp that onto the draw bar with a pair of vise-grip chain wrenches.
 
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