What's it weigh??

[Natman]

This should be fun, give me your best guess: 14' wide by 36' long, didn't notice but I assume it's framed with 2x4's as it's an older building. Fully finished inside, sheetrocked and trimmed out like a house, with a small bathroom. Couldn't get in the basement but assume the floor is 2x8 or 2x10's.

The customer, who's a commercial electrician, has it prepped with 4" by 3/8" flat bar, going under the rim sill and clear across, tied into the other side's flat bar. They are on 16' centers. I am going to guesstimate....25,000 pounds, let's call it between 20 and 25 K. I need to pick it off the foundation and set it on a trailer. The customer is in agreement that my 30 ton rig may or may not be able to handle it, and he's seen my load chart. He also knows that any damage caused during the lift, short of me dropping it, is on him. Our backup, if needed, is a half hour away, is a 80 ton truck crane that works with me from time to time.

A 10x12 framed garden type storage shed
weighs about 12 pounds per sq ft. Let's double that, times the building's 504 sq. ft, that's 11,753 pounds. Triple it, 17, 632 pounds, so 'm thinking my initial 20 to 25 K weight is in the ballpark, I of course don't care if it's lighter.

 

[Natman]

I just searched for "modular home weight", and came up with somewhere between 35 and 50 lbs per square, if 50 that'd be 25 K weight. That's probably a better, more comparable, starting point then using a garden shed.

 

[crane operator]

These two were 14' x 45-50' or so, and I think the empty one was 15,000, and the full one was 18-20,000 lbs. The empty one was just flooring and bare studs inside. The full one was lined inside with cedar or pine carsiding, a kitchen, bathroom and appliances. And all their furniture. They are steel siding and steel roof.

The full one was down the hill on cement blocks. Customer bought the second one, and made them into a L on a steel frame on concrete pillars.

They were built like a "garden shed", with 4"x6" runners full length, then floor joists on top of the runners running the short way.

 

[crane operator]

I think you will be under 20,000. I'm guessing 17,500lbs. Is this like the price is right and I have to be closest without going over? Are there prizes?

 

[Natman]

Yeah, that's the spreader bar setup I'd want, the one I DON'T have, reason being I don't need it. I haven't used my heavy 10' bar in....4 or 5 years now. Turns out my 80 ton connection has moved out of the area, but the metal fab company he worked for is still there and he said they'd set me up with what I needer bar wise. I've given them enough work for jobs too big for me that I wouldn't feel too bad about that.

OK, Crane Op, got you down for 17,500, and I hope you're right! I'll try and remember to take a picture of the LMI. No prizes, other the respect of your peers! I find it great fun to guesstimate weights, and always seem to come in pretty close but always over, which is a good thing of course.

 

[crane operator]

You're going to need the bars going both ways, or else a "halo" / square bar set up. I actually prefer a square bar set up for doing houses and boats. Three bars really hurts you because you end up needing too much boom shot out, especially when your under craned. Wasn't a problem with my 100 ton because I had plenty of tip height. Square bar cuts down on your rigging length, so you can get right down there close. I've got a square set up, but its a little small for houses, I just use it for boats. I bolt the four pieces together to make the square, so I can haul it broken down to straight pieces.

The way your customer has the flat bar put in there, you won't be able to pull any direction except straight up. Going to need some bars, you can borrow mine if you come get them and bring them back.

 

[Dozerboy]

I'm going to say 30k. That's just a guess from my demo experience. The hardest part is the Furnished part. Are we talking Ikea here or a horder that buys his furniture from the Amish.

 

[Tags]

I think you will be under 20,000. I'm guessing 17,500lbs. Is this like the price is right and I have to be closest without going over? Are there prizes?

17501lbs…..

 

[crane operator]

Tags knows how to play this game.....

 

[Delmer]

I'd figure out the framing and take a guess, but you've already got it closer than I could guess. It looks modern so I'm guessing there's no full dimension hardwood in there, maybe not even 5/8 drywall? minimal tile or cement board, cedar siding but over foam or buffalo board, only one layer of shingles, no room for a huge kitchen. Hope for the light end, but be prepared for the heavy end I suppose.

 

[Natman]

I'm going to extend this 10' lifting beam that came with my old Manitex 101S, 3' on both ends with more 8" channel, and move the lifting ears out towards the ends. A telescoping spreader (8'-14') came with my National, and it's so much handier I haven't used this beam once in several years. In fact I almost took it home to use as a corner post on a new fence line, glad I didn't.

I'll also buy a new 14' length of sch. 40 3.5" pipe, put some ears on the ends, and then I'll have the 3 spreaders needed for this job. The customer will pay for the needed material, I'll keep them, and do the work at a discoount. Or not, I'll make that part up as I go. Looking at the work he's already done with the flat bar on the building, he's obviously wanting to do it right and isn't cutting any corners, so I'll do the same. New steel sure is expensive! I hit the local scrap yard first, as always, but didn't get lucky.

 

[crane operator]

So did he lag the upright bar to the walls? Or are you going to be totally reliant on the single weld at the bottom by the sill where the underneath bar is welded to the vertical? If nothing else, at least lag/ bolt the vertical steel to the bottom sill/ floor joist rim board. It would make me a lot more comfortable, than just lifting off that weld.

 

[Natman]

No lags visible in the walls, and I have not had access yet to the basement below to see what he did below. I assume it's a bolted connection, like he did up top if you look close. That upper part looks fine anyway.

This will be one of those lifts where I'll pick it up a couple inches, and then do nothing for a minute or so while it's still over the foundation while we all think about it for a bit, mostly just giving it time to do something if it wants to while still safe, and then just swing 90 degrees and set it on a trailer, all while only 3 or 4' above ground level. About in another week, I went back and measured to my center of rotation, 17' from the one side, less than 12' if I setup in the drug store lot next door. If it's 25 k or more, I'll do that, that's my backup, the 80 ton is tied up so it's all on me. I'll be surprised if it's over 25, more like 20, maybe.

 

[Natman]

Looks like I'm the winner in the guessing game: 26,300 lbs on the hook! What's my prize?!
The day before, setting trusses with a guy who used to be around modular homes, he guesstimated 17 to 18 K, this morning my customer guessed 17.5K. He did have the flat bar bolted underneath continuously, and my spreader bar mod (10' to 16') plus the new one of 3.5" sch 40 pipe both seemingly worked perfect, both still straight anyway. News to me was the fact I also had to unload it, after watching it get trucked a few blocks down a busy street right at lunch time. A 1800 series National 40 ton (what I have my eye on, some days) would have done it without resorting to any cheating, but then again what I have is overkill for 90% of my work, house trusses. I'm billing for the material for the spreader bar mod plus the new one's pipe, plus my time, most of it anyway. My shop time for the welding is free, but billed for the crane time, and I get to keep them, of course the customer is happy with that, and that works for me also. .

 

[terex herder]

So how much rigging was on the hook?

 

[Manistar]

Nice pick, I'd have to say you're braver than I would have been. What are your two top slings?

 

[Natman]

About 800 pounds of bars and rigging, top rigging was 4" slings. Maxed out and then some. The only reason I proceeded after seeing the weight was it wasn't an overhead pick, with people involved, and never got higher than a few inches. Well, a bit over 3' as a trailer was backed under it. The only other bigger boom trucks or cranes are 50 miles away, my 80 ton Terex connection only 20 miles away was tied up. I'm sure there is a formula for figuring the compressive loading on that 16' bar, (that was the biggest unknown to me anyway, and concern) based on the sling angles and the load, but I don't know it, I suppose it got proof tested yesterday pretty good so I won't have much qualms about using it for lighter loads in the future, though that's unlikely. They plan to put this building on a foundation at a later date, nothing was mentioned about that to me, where or when, probably right under the power lines at the edge of the lot, so as not to kill too many parking spots. If so, and if I get the call, I'll do it house mover style: railroad jacks, I beams, and pipe rollers. Just now had the thought..., if I had to do it over again, knowing the weight better, I'd have blocked up under my rear tires so my bumper would have cleared that concrete porch and gotten 5 or 6' closer.

That reminds me, they are doing some major interstate overpass work in my area, and I see they have driven piles directly under some very large power lines. Having the seen the pile driver in action at another location, I know the overhead clearance it needs, and it would for sure have been into them. I need to stop at the jobsite some day and ask them how the heck they did that.

 

[Impact]

Not knocking what you did in the least. I’ve overloaded every rig I own multiple times. Especially the boom trucks and small truck cranes. The AT cranes concern me a bit more when overloading them because I never see the rig get light on the outriggers (tipping). Almost always a structural overload. I’ve overloaded the ATs also and to my knowledge didn’t hurt anything. That I know of. Or did I? Will it show up on the next lift? Or the lift after? Or next summer?

 

[Natman]

Complicating things somewhat, is the 1400 pound counterweight (a 1300 series option for carriers without enough weight) I installed a few years ago, without telling the LMI. My take on that is that the LMI is still accurate and while I didn't gain any structural strength (or at least I assume I didn't) I for sure gained more stability. It never grunted or groaned, the winch didn't squeal, and my butt meter was in the green, even after rotating 90 degrees and booming down a bit to set it down, (while only inches above the ground) clear of the outriggers. After 5-6 years of running this rig, if anything the LMI is very conservative, as far as the indicated weight goes. Numerous truckers who recently crossed a Port scale with a load I later pick seem to back this up: the LMI always saying it's heavier than the truckers said, even after allowing for the rigging etc., which is the way I like it.

 

[Manistar]

I thought those looked like 4 inchers. A 4" 2-ply is good for 11,000-11,500lbs WLL depending on the manufacturer, but 20' straps with 16' spread puts them at 65 degrees which reduces them by about 10%. So those straps would have like a 20,700lbs wll with your spreader. Like wise your 26,300lb lift had a force of 10% more, making it more like a 29,000lb pick on your top straps. I know they have a 5:1 safety factor so realistically you weren't in any danger but I don't like exceeding the WLL.

Then looking at your crane chart you're in your structural with 24,000lbs @15' radius and 18,450lbs @20'radius. Even if you're cheating with your last 15% that's 28,235lbs and 21,705lbs and you know when you swung it over the side to the trailer you were 17'+ of radius with half of a 20' outrigger spread and half of a 14' house. Obviously there's chart in between 15' and 20' but you were in uncharted territory. I think anyone who's run an old Grove has gone till they float a pad, myself included, but in a structural chart that's flirting with disaster.

Then you have your unknowns in the spreader bar and the house rigging flatstaps. I know it's your company and equipment but that's one I think I would have walked away from. Not trying to dog on you, I just like cranes and analyzing picks and like I said you're braver than me.