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Trailer With Inside Extendable Bridge Crane...

michael.kitko

Cast Iron
Joined
Oct 30, 2012
Location
Pontefract, UK
First off, please excuse if I posted this on the wrong section. I had no idea where to put this or all this.

Anyways, I have been looking and can't find any good examples of how this was done or better yet ratings. Of course tips and design points would be much appreciated and welcomed as to where to start. So, has anyone seen anything like this in a trailer?

Boring part: Now the reasoning. There have been times I've needed to move a mill or lathe from one site to another. There have also been times where I've needed to unload a trailer to make room for something else. I think something like this would come in handy and would rapidly speed trailer unloading and loading.

Thanks in advance,
Mike
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I've never seen anything like that. I believe you'd need out-riggers of some type to prevent roll of the trailer body and uncontrolled run out of the beam. Could a jib-crane be substituted? Not sure if that's any better from a load control standpoint. :D They make 1000 lb capacity deals that mount to the rear corner of a truck bed and include a stabilizer jack in line with the column.
 
This kinda reminds me of the system that memorial masons use to move gravestones and tombs around. Long beam with a gantry crane/hoist. Only difference is that theirs are open trucks.

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I have seen trucks with that type of crane and I think I saw a trailer setup that way for setting propane tanks. I doubt many enclosed trailers would have the roof structure for supporting this and would be limited to working on the center line of the trailer.
 
Sanity check. Would you feel comfortable putting the intended load on the roof of the trailer? If not, then probably you should not suspend that load from the roof.
 
Sanity check. Would you feel comfortable putting the intended load on the roof of the trailer? If not, then probably you should not suspend that load from the roof.

Sanity check TWO.

How often does one have the sort of "work" for such a rig as actually fits within its capability?

For long years now, it has made waaay more sense for my use to rent precisely what a given task needs, for only as long as it is needed, be able to reject a junker, store or maintain "nada" of my own, and always have the "right" item of MHE for the job to-hand.

Seldom even the same size and TYPE of forklift alone, twice in a row.
 
It has been several years and my memory sucks but here goes anyway. Montgomery Elevator had some custom semis for delivering elevator components. Essentially they had a small bridge crane. The crane rails were attached to the side walls of the trailer. As I recall there were pivoted outriggers for the crane rails that would allow the bridge to travel beyond the floor of the trailer. I only saw it once and that was many years ago. As I said, memory sucks.
 
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Something you might be able to look into is a scale certification company. I saw one unloading thousand pound weights onto a truck scale platform, to certify it. The crane extended out the back of the truck body. If memory serves the company name was "Keystone Scale" here on Pa. Maybe there is a company near you that would let you check out their truck or could give you info on the body company. PB
 
A simple post and swing-arm crane, with a hydraulic ram to raise and lower the arm would avoid the uncontrolled deployment issue and allow the unit to be mounted on a substantial flange bolted to the the floor, perhaps with a brace to the box corner post, where the leverage exerted would be much reduced, along with the chance of damage to bodies, human and aluminum.

The arm could be made just shorter than the width of the door opening and made to swing through 180 degrees. If you really wanted to get fancy a trolley with a positioning screw running along the top of the boom would be the ultimate in control. Something like an old lead screw with a bevel drive and a hand crank at one end.
 
I have actually seen a few of these, and the ones like the one you show are 300 to 500lbs maximum, and that is after substantial re-inforcing of the trailer roof.
I have also seen a local machinery mover, who, years ago, had a crane somewhat like this, but with a very large and heavy I beam frame that supported it, completely independent of trailer box.
In general, this is mickey mouse, and will fail eventually, unless you overbuild to the extreme.
No way will it move a mill, even a relatively light one.

Buy one of these instead.
STAHL Cranes | 2 lb. | 32 lb. | 4 lb. | 5 lb. | 8 - STAHL Truck Bodies

or, a tilt bed trailer.
 
Thank you for all the replies.

I think the one that I saw was actually built into the frame of the trailer and not attached to the roof. Unfortunately, I did not take good pictures of it, like I should have.

I do agree with the outriggers. I honestly don't think this guy had those and was lifting some impressive tables with that thing. It does look homemade. That was a good point on the fact that the load could shift and I was thinking of trying a pulley system, but I like the idea of running a lead screw setup like was mentioned.

DiggerDoug, yes that is almost exactly like what I want.

Thermite, I would like to say that I don't do this very often, but that would be lying. I'm not currently active with a business, but when I was and my future plan would actually save me time and money if I were set up to do this. I know most guys charge on the back end for lifts that are required, but I like to work lower income jobs, where clients would like to save that money.

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Thermite, I would like to say that I don't do this very often, but that would be lying.

Hear yah. It has been my practice to load a pickup - or a MOPAR Caravan - with a selection of my skates, straps, chains, ramp, etc - and a locally-rented KD "Bluebird" engine hoist because I wasn't sure what a seller actually HAD, or if I could rent one 400+ miles away at the go-fetch point of an item of Old Iron.

For a time - I toyed with the idea of fabbing an Aluminium-alloy gantry - or altering one - that could be knocked down (the "KD" in Bluebird - still made, but under new ownership).

Rather than becoming part of the structure of trailer OR truck OR van, it would be extracted, assembled, used, knocked down for easier storage, return trip.

It is actually faster and easier to put a KD's individualy lighter components together than it is to "unfold" some of the "folding" hoists. The KD has a wider and safer leg stance and net-net takes up far less travel space, and more flexibly what with separate parts, as well.

Same again with a gantry. Not folding - take-apart is what travels in tighter space.

Such a rig could have very good general utility, on-site or off, vehicles not necessarily involved at all.

Such goods are available commercially, of course.

Most ideas with any proven merit for real-world needs always have been. Most are cheaper, used but good, than DIY'ed as well.

:)
 
I have seen trucks with that type of crane and I think I saw a trailer setup that way for setting propane tanks. I doubt many enclosed trailers would have the roof structure for supporting this and would be limited to working on the center line of the trailer.

Yes, you see propane trucks with this monorail, and also septic tank trucks.

I also agree about the trailer roof not being strong enough without some major beefing up. Most of these enclosed trailers have a roof you can barely walk on without collapsing it.
 
Measure the distance between the last 2 rollers and the fully extended length of the slide out beam. The leverage factor can be computed. If you extend out twice the distance between rollers, then you cut your load capacity in half.
 
The local fun fair has something like that in one of there trailers, i do electrical maintenance for them. Theres is not a traveling gantery as such though, IMHO its not really needed, theres is more a track running the length of the trailer and can extend out the back a fair ways, at least a good 6-8 feet. IMHO based on how tippy air ride trailers are side ways would not be wise.

With the fun fair crowd ratings are a moot point, but it feels bloody solid in use, 1/2 ton is easy and the frame work very much extends through the trailers floor into its chassis. Really don't think you need a full x/y travelling gantery, a central carriage works just fine for the typical width in a given trailer, key thing is a low head height block, a std carriage, std block std hook and you have lost way too much ceiling height for starters. In there case it allows them to pick carriages straight up off the ride and into the truck, saves on man power and over here thats one of there ever biggest costs.

Real problem in a commercial setting this weight comes off your cargo weight limits, hence it needs to be as light as you can make it or it becomes self defeating and suddenly being able to pick 20 tons might not help you move much any more!
 








 
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