What is a reasonable range for load on the mid-point of a 2' by 1" box steel tube?
I'm moving several big heavy boxes; the biggest is 3' x 4' (by 6'6" high) and weighs 3400 lbs (big transformer). My building said "no" to my using a Rol-a-Lift at each end, since that would put 800lbs on a square foot under each wheel (my limit is 120 lbs static, or probably 360 lbs rolling). I'd like to make a "mover's dolly" to put under each end (3' wide by 2' long, 8 casters to distribute load better); each dolly needs to carry as much as 2000 lbs., since part of the path will be 8 degree incline. I am thinking of using box steel, since the dolly needs to be as low-profile as possible, to minimize the number of door frames that need removal. I'll need to use at-least 8 2' pieces of 1" box steel, will probably use 11, but could easily use as many as 17 or so.
Any hints on the load that box steel can take would be helpful; or other hints on how to spread load (while minimizing height) when moving a heavy object would be appreciated.
Laid flat or standing? Standing it's possible...laid flat, it will not suit your application.
Quote from: makenzie71 on August 23, 2006, 05:43:17 PM
Laid flat or standing? Standing it's possible...laid flat, it will not suit your application.
Layed flat. You're right: I could weld 24 pieces of 2-ft long 1" box-steel together like a pack of pencils, and it still might not support 2000 lbs at midspan. I wonder if there's anything like corrugated steel, an inch thick, that can support lots of weight without buckling.
If I could afford more height, then I could just use 4x4s. I'm sure eight 2' lengths of cedar 4x4s should be able to support 2000 lbs at mid-span, and that's cheap!... but cost me two more door-frames I'd need to remove to fit through.
Just out of curiosity, why are you trying to move a 3,400lb transformer over a 120lb / square foot floor?
I suggest you tell your company to hire a rigger. If the transformer goes through the floor it's their problem, not yours. :)
They would hold if you stood them up and welded 2 side by side. You'd have to build your frame entierly like this with all the perimeters doubled. A 36 X 48 frame built like this can hold up to 2500lbs safely (mathematically...in practice that number is completely irrellevent). I would then built a grid inside the structure in the same manner. I wouldn't use casters, though...I'd build a trailling axle carrier to mount four 8" inflatable wheels with built in bearings. Same thing up front, instead of a trailing carrier I'd use a caster with four 8" wheels (mounted 2X2) with a long handle so you could pull it around like a waggon. Doing this, if you use good wheels and tires and are a competant welder, you would carry your loads low enough that a neglected pencil or pebble could ruin your day.
Why in the name of god?
I've got some ideas, but I would need more details. I also tend to over-engineer everything I build by 75% to 100% so...
Mak sounds like he's got a good idea of what's going on.
What about some casters at the midpoint? That way you don't have as long of a span to support. I don't know what the terrain is so I could be totally dumb.
why not round tubing.. its stronger and doesnt have the problem with box tubing where teh edges are teh weak points..
but i think you should use a professional mover.. 120lb/foot live load is too little.
How about getting a bunch of strong steel pipes and move it old-school building-the-pyramids style? That shouldn't cause any excessive point loads. Don't know how you're going to turn any corners though. :icon_mrgreen:
Quote from: Egaeus on August 24, 2006, 05:33:51 PM
How about getting a bunch of strong steel pipes and move it old-school building-the-pyramids style? That shouldn't cause any excessive point loads. Don't know how you're going to turn any corners though. :icon_mrgreen:
mordern technology has made it possible to navigate corners in this method...instead of using long rollers like the Egyptions did, he'll need to use these:
http://glassmarbles.com/images/marbles-jb2004f.jpg
Quote from: makenzie71 on August 24, 2006, 05:52:56 PM
Quote from: Egaeus on August 24, 2006, 05:33:51 PM
How about getting a bunch of strong steel pipes and move it old-school building-the-pyramids style? That shouldn't cause any excessive point loads. Don't know how you're going to turn any corners though. :icon_mrgreen:
mordern technology has made it possible to navigate corners in this method...instead of using long rollers like the Egyptions did, he'll need to use these:
http://glassmarbles.com/images/marbles-jb2004f.jpg
:laugh: :laugh: :laugh: Now that would be a nightmare to manage. Waitwaitwait! I have to pick up the marbles and move them to the front!
Quote from: Egaeus on August 24, 2006, 05:33:51 PM
How about getting a bunch of strong steel pipes and move it old-school building-the-pyramids style? That shouldn't cause any excessive point loads. Don't know how you're going to turn any corners though. :icon_mrgreen:
Actually I was thinking of that as I logged off last night. But on an incline that would suck.
If it was good enough for the egyptian slaves....
Quote from: GeeP on August 23, 2006, 07:35:58 PM
Just out of curiosity, why are you trying to move a 3,400lb transformer over a 120lb / square foot floor?
I need to bring 480v up to my floor, and step it down to 208v. Copper is too expensive (and voltage drop too high) to bring that much 208v up to my floor.
Quote
I suggest you tell your company to hire a rigger. If the transformer goes through the floor it's their problem, not yours. :)
I have a crane and gantry coming to deliver it to the floor. They want to use a hand-cart/hydraulic lift on each end to move it across the floor, which has 4 wheels ( 800+ lbs per wheel!). A structural engineer I hired said that would be OK, if I built a 9"-high raised floor over the deck, to distribute load and point load. The way he describes it, the raised floor would increase the footprint of the unit by about 18" x 18" while rolling. But the added height would mean I'd have to demo some doorways to move the unit. Also, there is enough lumber in the project to build a house.
I've heard that rolling load limit of a floor can be 3x to 4x the static load(?), so I was hoping to get the load down to 200-300lbs / sq.ft. (floor is rated 120lbs
static). My thought was, rather than build a raised floor to distribute the load (as the engineer suggests), why not build a rolling cart that does the same thing, with lots of wheels on the bottom (think: a pyramid structure riding on a thousand roller skate wheels).
My plan was that if I pick four points near the corners of the pallet the transformer sits on, equal distance from the center of gravity, and put a dolly under each point, then there's 850lbs pressing down onto the center of each dolly (no problem for the dolly: most mover's dollies are rated 1000lbs.) If the dolly is 2'x2', and the weight is on the center of the dolly, then there's 212lbs on each caster (no problem for heavy duty caster), and 212lbs/sq ft rolling weight (maybe OK for a 120lb static load floor?).
QuoteWhat about some casters at the midpoint?
I could support each dolly with 8 casters (4 corners, 4 sides) rather than 4. I could put the casters in a circle around the load point, if I wanted them all to carry the same weight. The problem is while the riggers roll this thing in, it has to climb an 8-degree ramp (I have no idea how you push 3400 lbs up a ramp!). As the front set of wheels of the leading-edge dollies rise up the ramp, the unit will put a bit less than half its weight on the front dollies... but worse, the weight will be in a thin line across the middle of the dollies, and those extra wheels won't be touching the floor. The same thing will happen to the trailing dollies as they mount the ramp, except that will be more than 50% of the unit's weight on those trailing dollies (I think 58%?).
The dolly would have be sturdy to support that much weight. Four 4x4s, supported by 4x4s cross-wise in the other direction , held together with Simpson clips and with 2 sheets of 3/4" ply on top and bottom, should do it (it's only 918 lbs per dolly, even if that does press down in a line). That would be kind-of like taking a big pallet, and resting its the four corners onto four smaller pallets. Unfortunately, the transformer case is 78 inches high, and I think I'm going to need a couple of inches of plywood covering the floor, so adding 9" of "dolly" (plus the casters) would mean I'd have to demo a bunch of door frames to fit the unit through. I may have to do just that, but I'd prefer to make the dolly low profile (!).
I'm looking at some datacenter floor tile to use as a "dolly" base: a 1" thick slab, 2'x2', rated to 1000lbs pressure on 1" square without deflection (absolute limit before failure, 2470 lbs). Put four low-profile 300lb casters on that (load-height 2.5 inches), and I can keep my transformer + dolly down to 80.5 inches in height, and fit through almost all the doorways. I can test the dollies for suitability at the riggers beforehand. If I need to, I could make each dolly from two tiles, but then I would have to start removing door frames.
So, the goal is: spread the load out, long and wide. Don't add any more height than necessary. And next time, buy smaller stuff.
Quote from: Rema1000 on August 24, 2006, 07:11:13 PM
I'm looking at some datacenter floor tile to use as a "dolly" base: a 1" thick slab, 2'x2', rated to 1000lbs pressure on 1" square without deflection (absolute limit before failure, 2470 lbs). Put four low-profile 300lb casters on that (load-height 2.5 inches), and I can keep my transformer + dolly down to 80.5 inches in height, and fit through almost all the doorways. I can test the dollies for suitability at the riggers beforehand. If I need to, I could make each dolly from two tiles, but then I would have to start removing door frames.
So, the goal is: spread the load out, long and wide. Don't add any more height than necessary. And next time, buy smaller stuff.
That is actually a f%$king superb idea. And much more feasible than any of our cracked out schemes.
Why not just toss some of the datacenter tile down and roll over it? The you could have it on only 4 one square inch points and be totally fine.
Interesting... Light manufacturing? Office?
Again, I'd be careful with moving this thing. Hiring a rigger and letting them deal with possibility of leaving a perfectly square hole through multiple floors is the best choice. Sometimes it's nice to show the boss what you can do, other times it's best to hide while somebody else makes a fool of themselves. If that isn't possible, here are a few thoughts.
1) Find some toe jacks with casters or some low-profile machinery casters instead of moving dollies and ditch the pallet. That might provide enough space to use the engineer's idea. Then your ass is covered. Chain the hell out of the toe jacks so they don't slip out. Check here:
http://www.squaremcompany.com/Heavy-Moving-Equipment/index.html
2) If height is still an issue, I might be inclined to use these:
http://www.aerogo.com/pdisplay.php?product=Aero-Plank_System
You could distribute the load perfectly by ditching the pallet, building a frame for the aero skates, and placing the transformer on top of the "hovercraft". You'll need 29 or so square feet of aero skate. However, you'll also need a way to control it up that incline or it'll take off like a rocket if something lets go. BTW: These things use AIR. You'll need a diesel compressor or a hefty shop air supply close by. They don't like variations in the floor either.
3) Another thought would be to use several I-beams placed at 90 degrees to the floor structure. Shim it such that it will distribute the load over enough structure to support the weight. Run the transformer down the I-beam on rollers. (Use bar stock, it won't crush.) ;)
Remember that while a given structure may be capable of supporting the load it may not be rigid enough. The structure must be significantly more rigid than the floor. If not, it will yield before the floor and be ineffective at distributing the load.
$10,000 to move a $15,000 transformer is expensive until it falls through the floor. :icon_mrgreen:
You really, really need to think through the incline. 3400*(8/90) = 302. i.e. it's the equivalent of pushing 302 lb. straight up. Don't think that one or two people are going to be able to just push it up without significant risk of it rolling down and wreaking lots of havoc.
302 lbs? I can do that by myself.
(I move appliances for a living.)
I agree totaly with Geep. Its best left to the Pro`s. They have the gear and experience (and indemnity insurance). Everyone is talking about cradles and designs and relative strengths but what crosses my mind is how are you going to lift and then position the transformer centraly on the cradle to start with? The way its done in industry is to lift each corner with crowbars and duffys, block it up with timber and slide a skate under it. They are very low friction items and take very little effort to move. Suitable equipment for lifting and moving loads such as skates and duffys (what we call toe-jacks) are available for hire
http://www.hss.com/g/70408/8t_Machine_Moving_Skates_4_Set.html
but what you lack is the experience and back-up if the job goes fun bags-up. If it slips off your homebrewed cradle half-way round then what? I have a list of contractors I use for similar jobs such as moving large electric motors and gearboxes etc around on sites and from what you say it sounds an easy enough job assuming the floor surface will take the weight. Find some companies get some quotes, I doubt it will cost as much as you think, particularly if you are considering spending time and money fabbing one off cradles. It must be possible to move it because someone put it there to start with. My guess timewise from what you say is a couple of hours for 2 men with the right gear. I havent seen mention of it yet but you need to consider the floor surface, if its smooth great, but nothing rolls freely over rough cast concrete with that sort of weight on it.
Quote from: GeeP on August 24, 2006, 09:00:24 PM
Interesting... Light manufacturing? Office?
Quote
1920s office converted to datacenter in the 1970s.
QuoteAgain, I'd be careful with moving this thing. Hiring a rigger and letting them deal with possibility of leaving a perfectly square hole through multiple floors is the best choice.
A crane company (think "Metro Crane") is going to fab the cart/dollies/whatever, and (somehow) push the thing in. Is a crane company a Rigger? They wanted to use a "Rol-a-Lift" to move the unit, but that would put the weight on 4 wheels, so the property owner's structural engineer recommended the temporary raised floor. I suggested using something with lots of wheels, which is the direction we're currently headed. However, the crane company doesn't have an engineer or even a CAD person to show their plans to the property's engineer; is that normal for riggers?
Quote1) Find some toe jacks with casters
Cool (toe jacks on casters). I could line the front and rear end of the unit with toe jacks on casters, and would have my 16 rolling points of contact. More concentrated than with dollies, but much simpler. Might not be too graceful when it hits the ramp.
Quoteinstead of moving dollies and ditch the pallet.
There's a rigid steel box base on each cabinet, so the pallet is sort-of integrated. The term "dolly" is sort of an aid to visualization: the pair of "dollies" at each end could be bolted together, or could even be a single unit, like a sledge on casters; it doesn't really matter. The important detail is where the weight of the transformer case presses down on that sledge, and how the casters are arranged around those pressure points; and how much weight the sledge can distribute evenly from the load out to its supports.
The crane operators will be buying casters for the purpose, and building whatever needs to be built to support the unit. They just haven't seemed too creative so-far.
Thanks for the tips!
Generally a "rigger" is the guy that sets the line on a lift, i.e. the guy at the end of the line on a crane. However, it can also mean someone or a company that moves heavy things by whatever method works. They can be as simple as "yeah, that'll hold" to "this design will carry precisely..." Most outfits seem to fall into #1.
Every once in a while I hear of something downright different. One story in particular involved putting a 3,000 lb lathe down a residential basement staircase. They ran a suspension cable from the footing of the house through a hole drilled in the wall and out to a truck crane. Then they ran the lathe down the staircase suspended in mid-air like a trolley on the tensioned cable. :laugh: 8)
I might try talking with other rigging outfits. I'm sure you can find one with an engineer on staff to help with tricky solutions like this one. The way I see it, the people you have now really don't want to accept responsibility for the project by forcing you to come up with the ideas.
:dunno_white: