New Log Truck

Whats the max load per outrigger? What surfaces will the truck operate from? I assume you wont be driving it across clients yards, improved and gravel surfaces?


For instance my manly lift has a max weight per outrigger of 2800lbs. Meaning in the most leveraged position against any outrigger, the max load will not exceed 2800lbs with 500lbs in the basket. Based on the size pads (rougly 11" diameter) at most I am exerting 30psi on any given pad. This means that except surfaces that cant be scuffed (the outriggers swing on an arc, can scuff grass/concrete/ect if you lift the machine 2' off the ground)I dont need pads. If I can get the machine to the location, chances are the outriggers will hold up.

Of course your out riggers will see ALOT more weight than that but in order to give you an idea of what sized pads you will need we need to know what kinda surfaces and whats the max weight. On the little (comparitivly) Prentice 120C mounted on Asplunds grab truck they dont use pads as they operate off the road all the time. However, because they are production based bone heads on heavy pics, especially in the summer, they can put diviots in asphault due the high PSI the small (maybe 6"x10"?) pad can create.

Perhaps a technical solution to a seemingly simple thing, but it offers mathmatically certian results. It would be foolish to carry pads (as a standard) that would reduce the PSI past that of what the tires produce, as if you can drive there, you can normally setup there.

One thing to consider also is the fact that the curbside outrigger could very well be set out on the grass to keep the truck from blocking the road. Knowing this it may be prudent to keep your standard pads as well as another larger pad to reduce the PSI (which decreases damage).
 
Whats the outrigger span? How big are the out rigger feet? The wider they are the better of course.

If you will be offroad a bit, you can figure for softer ground, and you DONT want your outriggers to fall out from beneath ya.

What radius is 21k at? The MFG should be able to tell you what the max loading is. Figure if its 21k at 5 feet, thats 105k of weight right there, plus the weight of the boom and alot of other stuff, minus alot of other stuff (including outrigger span). On cranes part of the extended information on the weight charts is the max load.
 
Beautiful, except the tiny diameter on the feet or whatever they are called.

With the 21k at 9' and the outrigger extending a foot past that, lets say the most per outrigger is 30k. At 70psi you need 430 sq inches or about a 20" square.

For worse case you could also get a 30x30 (or whatever size floats your boat and gets the PSI to an acceptable level) and put it down first with the 20x20 centered on it and the foot of the outrigger centered on it, perferably with the:

The outriggers should have a cast aluminum foot or something to go over the end for working on hard surfaces... weird it doesnt. They aint good for bridging gaps though, like having the pad only supported by the edges.

A simplified generalization, but your tires operate at a certain PSI, the air is what holds the weight of the truck. If you can drive your truck where you put your pads, then you need no more PSI under the pads than what the tires carry.

Hope all this long windedness helps and makes halfway good sense.
 
Its bound to happen. We are tree guys you know. I am especially fond of the bubble mirror on the front fender, THAT will be the first to get smashed somehow. Guaranteed.
 
Naw seriously, I just sent the pic to a good friend who has a tree company himself. Got an email from him and just about sprayed the computer with my beverage, I laughed so hard when it poped up. He's a funny guy.
 
Sounds like you're onto something there Carl. There are aluminum circles I could get ($900.00), but I would still need some pads under them. What I was thinking was to get an 18" square and stacking on top of a 30" or 36" square.

Or, a 30" square and getting an Alturnamat (smooth) and rip it in half. Use that on the bottom. That would be 3' x 4'.
 
A buddy of mine did roofing for a while and used 4x8 sheets of plywood ripped into 2' wide pieces to protect the siding from damage. To make the sheets easier to handle he used a large hole saw and drilled handles in both ends of the sheets. The edge of the hole was about 4" from the edge of the sheet. This made an easy handle. Two of the skinny sheets could be stacked and groundies could drag two stacks. It would be impossible to drag to sheets of plywood any other way. Having grab handles in your sheets makes them easier to lift and less likely to slide around.
 
Your gonna have to have something stiff so the piece doesnt fold up. The aluminum circles spread the weight out a good bit so you could get by with a thinner mat to a degree, or perhaps only needing one mat.

Your gonna need something might stiff to transmit the load evenly on the mat.

Look at the elephant feet on this crane:

http://gypoclimber.com/treehouse/download.php?id=4997

They spread the load out so they dont have to worry folding the 1" thick steel plates for pads by keeping the load focused on a small area.

I question how well the alturna mats will take the centralized load, they dont seem overly stiff. Stiff is just as important as surface area, lacking either one will increase the PSI under the outrigger and increase the chances of it falling from beneith you. As your truck can work as a crane it needs sure footing, too much liabilty for something so easy to prevent. An 18" square centered on a 36" square leaves 9" around the outside edge.. sounds better assuming both are reasonably stiff.

How big were those 900 buck alumium jobs? I figured they shoulda been included.
 
Thats 250 square inches per, woulda offered alot of additional support, perhaps only needing to carry 1 pad per side to keep footing under normal conditions. If you carried 27" diameter pads along with those pads that would give you nearly 550 square inches of contact area, with only 4.5" of the bottom pad extending past the top pad, which would in turn make it stiffer!

At 30k on the outrigger 550" sq would give you a paltry 54.5psi, just shy of double my light weight manly lift, but very good for support.

A 30" (diameter) pad would give you 706.5" sq and at 30k that makes for 42.46psi, even better. A 30" square would give you 900" sq or 33.3PSI which is nearly down to my manly lifts 30psi, very good stuff!

I would consider getting those aluminum pads, they increase your footing on the pad allowing for more options that could be better. I think over the lift of the truck they will pay off, had I ka-chinged that much on the crane I woulda told them to get stuffed if they didnt include them, nickle and dimeing aint cool
 
Maybe add a camera to the end of the stick so you can see out behind the truck. Those outriggers have to have some serious down pressure. Do the outriggers have to be extended all the way to operate the boom? or can you cheat and hope that common sense will keep it on its wheels?
 
I am pretty sure they can operate mid span and have a weight chart that reflects that setup.

For what that rig costs, to hell with cheating. Doing something that is against the manuals could void any insurance coverage, I dont see how that could possibly be worth it.

As to leverage on the outriggers. 9'x21k lbs=189k of torque. The outriggers are at 10'so load would create an additional 18.9k plus whatever the boom weighs. At 53'x2400lbs=127.2k lbs, which equates to 12.7k, plus the weight of the boom. This leads me to believe the max weight on an outrigger to be around 25k plus the weight transfer from the oposite side of the truck that acts as a counterweight, so lets say.. 45k max load on an outrigger? Its hard to calculate such things without knowing alot more than I do.

Perhaps a shortcut for worse case senario, Mark, what size bore does the down cylinder have and whats its max PSI? That will tell you the absolute worse the machine could have been designed for.
 
I would caution against using ram size/capacity as a limit. No doubt about it in my book, those parts are designed with a generous safety factor. I'd guess 1-1/2 to 2x. I'll say this at any rate; it would surprise me if a competent engineer went much less than that. There's absolutely no excuse for taking things right to the edge unless you're doing something like designing a plane to fly nonstop around the globe without refueling.

You know, if you worked solely over the back bumper you wouldn't even need to lower them stabilizers! hahaha!
 
Glens, your spot on. My point is that would be the ABSOULTE max weight that could possibly be on that outrigger.

Crane charts normally are at 85% of capacity. Altec said a crane must be able to take 117% of what the crane is rated for, those numbers dont add up necessarily.

Another option would be install a pressure gauge swing 2400lbs out at a 53' radius, and do the math. I still think it would be much simpler to call up the crane MFG and ask them, they should have that info offhand, or at least on a spec sheet.
 
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