Deuce/5 ton ROPS Kit?

[KsM715]

Now take that same excavator and put it on a rail car moving at 45-50mph and push it over the same slope. Not going to have the same results.

 

[SixSpeed]

I read through, maybe I missed it, what does anyone think of this design posted previously? Obviously a heavy wall material, maybe 1/4" or more.

I am in the process of working on a ROPS system, I want to use 2.5" .250 wall DOM, but am still working leads on finding someone to do the bending. Using rectangular tubing would eliminate this problem.

Edit: I realize that an actual "Cage" is the best way to prevent intrusion into the passenger compartment in the event of a rollover at speed, but that is a HUGE increase in cost/work/design/etc. I would think something like this could at least HELP in most circumstances. I also realize that your life if worth more than anything, but something is definitely better than nothing.

 

[jesusgatos]

I think that might be the best way to approach a project like this for most people. and something like that could be built to survive a low-speed flop, but a single unsupported hoop like that isn't going to do well in any type of rollover at speed. Really needs to be triangulated somehow to keep it from folding. Two straight legs like you see on all the Smittybuilt-type light bars would do a lot to strengthen a hoop like the one pictured above. Problem is, now you've got to go through the bed if you want to anchor those legs to the frame - and you do want to anchor those legs to the frame.

Another thing to consider is that if whatever you build is mounted directly to the frame, it will most likely affect how the frame flexes and could cause significant stress risers where the reinforced parts of the frame meet the unsupported parts of the frame. And this is something that you should definitely be concerned about. Haven't put much thought into it, but you might want to consider mounting whatever you build on some type of bushings. On smaller vehicles, leafspring bushings are often used for this purpose.

As far as material selection, generally speaking, you'll get a lot more strength by increasing the diameter of a tube than increasing the wall thickness. I'm building an M109 and I don't think I'll be able to fit anything larger than 2.5-3" tubing inside the cab, but if I was building a roll bar to put in the bed, I'd go bigger. Even something like 6" tubing, although it sounds ridiculous, wouldn't look out-of-place on trucks this big and will be a lot stronger than 2-2.5" tubing.

 

[SixSpeed]

Frame flex is a major issue with something like this, I agree. Its something I struggled with when making the Exocage for my Unimog. In the end, as best as I tried, I still sacrificed some frame flex, but that was fine with me in the name of safety. Ended up using bushings at frame joints. Added a lot of complexity to the design. Open to ideas...

 

[jesusgatos]

Oh, and on the subject of rectangular tubing: nothing really inherently wrong with mitered corners like those, but those butt-welds should absolutely be gusseted - and it wouldn't be a bad idea to go ahead and weld a flat plate in between each mitered joint. Not sure how best to explain exactly what I mean, but basically, you'd cut a flat plate (of at least the same thickness as whatever tubing you're using) to fit between the two tubes at each mitered joint. Make sense?

 

[SixSpeed]

I know exactly what you are talking about for strength along those welds. I know what you mean about welding on a plate at the ends of each tube before welding the...err..tubes together. Was thinking about that earlier.

 

[jesusgatos]

Yeah, working off something like that hoop that you posted a screen-shot of above, I'd probably mount that directly to the frame, making sure that the size and shape of the mounting plates are optimized to avoid concentrating the type of stresses that we're talking about. The I'd probably look at mounting the two triangulating support-legs (the ones that I was talking about in the 1st paragraph of post #123) on bushings. If I was working with a normal cargo truck, I'd probably pierce straight through the bed, cutting holes just slightly larger than the diameter of the tubing), and then bolt those ends of the triangulating support-tubes to brackets that would only be bolted to the outside of the framerails. Those tubes won't do much to restrict torsional twisting, but could see them stiffening the frame considerably between the four mounting points when yore looking at it from the side and imagining it flexing up/down like a suspension bridge. Think that it would be wise to avoid tying those tube mounts in to the top/bottom of the frame for just that reason (like an I-beam, the top/bottom sides of the frame are doing most of the work).

 

[jesusgatos]

I know exactly what you are talking about for strength along those welds. I know what you mean about welding on a plate at the ends of each tube before welding the...err..tubes together. Was thinking about that earlier.

Here's a link to a great example of what I was talking about, just for anybody else that might be interested. Lots of other cool stuff in that build-thread too. Top-notch fab-work right there....

 

[Jones]

If the following sounds angry, I apologize in advance. We've just lost a member to an accident which may well have been prevented if other drivers had been paying attention to what they were doing.

All of the videos and pictures are of systems designed for single vehicle, slow speed rollovers. Construction or farm equipment NOT traveling at road speeds.

Most ROPS designed runs into an immediate problem as soon as it's "customer assembled or installed". Not everyone has the same level of expertise as the structural engineer(s) who come up with a ROPS system, or professional installers.
The best ROPS in the world doesn't guarantee 100% survivability. The best we can hope for is to show due diligence.

Slow motion films of vehicles as big as semis involved in accidents shows that at times they shake like a wet dog. So frame flexibility for one is definately a BIG factor to engineer around.

As long as I'm tossing out ideas, what about this one; a break-away cab as 'escape pod'.
After the snickering and flaming dies down... consider that, from the moment of impact on, the deuce or five-ton isn't going to become magically lighter. If the worry is being hurt/killed by 13,000+ pounds of chassis, power-plant and drive train then one logical solution is to get the he11 away from it.

All of this previous suggestion is impractical to say the least so we're left with driving VERY, VERY defensively anytime we're out in public with our military vehicles.
For the benefit and betterment of our hobby and public image we have to remember that, on public roads we're surrounded by civilians-- a few of which shouldn't even be allowed to start a car, let alone drive it.
Add to that mix a large, impressive, unusual vehicle and what little awareness of their surroundings they may have had goes out the window-- and they stare at the object like a moth at a flame.

One of the best ways we can honor our lost member(s) is to continue to present our hobby and interests in as positive a light as possible.

 

[jesusgatos]

Thinking in terms of creating an escape-pod isn't crazy at all. I've referred to the rollcage I'm planning on building inside the cab of may deuce as a safety-capsule when explaining what I'm trying to accomplish. Only trying to maintain the integrity of the space within the cab, in order to protect the occupants. Will not be tied into the frame at all, and if the cab separates from the body, so be it. MUCH different from how I usually design/build roll cages.

 

[saddamsnightmare]

August 2nd, 2011.

Interesting video of the crawler backhoe flip. I agree with the assessments above, that test was staged under the best possible conditions (EG: no obstructions to impact the cab, and the boom being partway up helped shield the cab. A deuce flip at any speed above 3 or 4 miles an hour is going to be a different situation althogather. The best safety device from an accident standpoint would be a 16" naval gun shell casing, but from a practicality standpoint, we are never gonna be able to engineer out all the OTHER fools on the road. The deuce was designed as a very slow speed tactical truck, and even then the designers recognized there was going to be a certain mortality factor among the drivers in certain situations.....
Volvos and Saabs are supposed to be very safe vehicles, but even their drivers manage to exceed the design envelopes every now and then... Perhaps my conductor was right, "Life's Terminal, nobody gets out of it alive".....

 

[mlwats1@hotmail.com]

we do not need OSHA and DOT getting together and causing problems

 

[kastein]

Oh, and on the subject of rectangular tubing: nothing really inherently wrong with mitered corners like those, but those butt-welds should absolutely be gusseted - and it wouldn't be a bad idea to go ahead and weld a flat plate in between each mitered joint. Not sure how best to explain exactly what I mean, but basically, you'd cut a flat plate (of at least the same thickness as whatever tubing you're using) to fit between the two tubes at each mitered joint. Make sense?

I would fish plate as well. Cut a plate to go across each butt weld, bore holes ~3x plate thickness in a few well chosen spots on each side of the butt weld, then rosette and perimeter weld the plate down.

As long as I'm tossing out ideas, what about this one; a break-away cab as 'escape pod'.
After the snickering and flaming dies down... consider that, from the moment of impact on, the deuce or five-ton isn't going to become magically lighter. If the worry is being hurt/killed by 13,000+ pounds of chassis, power-plant and drive train then one logical solution is to get the he11 away from it.

Fully agreed. If my truck is involved in a rollover, it is a lost cause to try and avoid damage to it, it will be a total loss. The only question in my mind is - am I going to be a lost cause also? I would obviously prefer to remain intact, and you are right, the further you manage to get from a rolling 13-20 thousand pound chunk of scrap metal, the better your choices of survival. I will take a roll through a ditch and chainlink fence in a deuce cab over a roll through the same while underneath a deuce any day of the week.

 

[quickfarms]

How about mounting a quadcon or tricon on an iso bed that is securely mounted to the frame?

 

[ALFA2]

As far as to add to a topic of a cage in cab, ( not tied in to the frame), thre was an upgrade light Armor kit for Deuce cabs that consisted of 1/2" contured armor plates that bolted together in the cab, firewall, cab floor, and cab back to form a box thath was very structural, and did not take up much room in the cab when assembled. It was available to USMC modified trucks in gulf war 1.

I have not seen the cab top that went with that kit, but lots of holes on the cab back plate, so possibly one exists for it somewhere. Such a combo would increase the cab's structural integrity greatly, and would prevent the cab from being easily crushed if it was roller over on. Also, a direct solid impact to a cab so armored wold possibly break cab mounts easier, letting the cab move some, (possibly far away from the impact) instead of collapsing in.

From the outside the cab there is no part of this armor kit that is visible, and no roll-bar type pipes are crossing an already tight cab inside either.

If such can be located and measured and gotten ideas / temples made from it, it could help someone who is attempting to build some more safety into their Deuce, without making it clumsy or a road warrior reject ride.

It was some years ago, I do not know the nsn numbers or other part numbers for this kit, but someone here probably has one just siting in the corner with a manual attached... lots of knowledge is available on this site, just need to look.

I will follow this thread, hope it helps some.

ALFA2

 

[FASTNOVA]

Here is a picture from another thread on here. It's kind of hard to see without getting some better close up pictures how that cage is mounted to the frame. It looks to be some pretty thick tubing.

 

[Westex]

I'm working on this project for all of us; question: Is that pipe connecting the cab to the bed? Fastnova, I would like some pics if you have them of this.

 

[jesusgatos]

Yeah, looks like some sort of frame-mounted outrigger to me.

 

[FASTNOVA]

I'm working on this project for all of us; question: Is that pipe connecting the cab to the bed? Fastnova, I would like some pics if you have them of this.

OK, looks like it might be some type of attachment for the gun turret. Here is the link Navistar Defense

There appears to be an mounting point that comes out from under the cab that attaches to the frame rail then at the back it would bolt to the bed. That does not seem very sturdy, but not sure how that bed is designed.

 

[Westex]

Thanks for the link; I've only owned a 923 now for about a week and am studying various things about the truck and trying to configure something in my head and on paper, but so far it looks daunting. Whatever will work must be attached to the frame, from what I've seen from (various wrecks), trying to attach to the bed is a no-go. I'm going to keep at it, but it will take time.