I need to fabricate a spreder bar for the wider truss sets.when the wood trusses get much over 50 feet wide they get pretty limber.I was thinking of using 4 inch pipe with 1/4 inch wall,about 25 feet long whith clevis top and bottom on each end so I would have a "v sling" on top,then short chokers hanging on the bottom to hook the truss.All ideas and opinions welcome.
Ive sat truss's over 50 ft to 55 ft .. no bar just a pair of spreader's... very limber.. I cant see a bar giving an advantage unless theres some support for the "peak " of the truss ...if you just hook up two points they may fold if they wobble .... now there is another way ...but it was to time cunsuming for the carpenter's not to mention a bit of a learning curve .. I need to draw it ... give me a bit of time here ..
what this will accomplish is ..pulling the weight in a pyramid ..so that equal weight is pulled on three points and the peak is supported .. you need wire rope ..something that will render easy through the shackles or hooks if you dont have snatch blocks or the truss will be harder to set level ...also the truss will have to be laid as much to vertical as posiable to avoid just pulling up the ends while its on the ground ... any questions fire away ...but i have used this in similar situations without fail ...you just need to bring people up to speed...
That looks good from an enginiering piont of view but the carpenders will hate it.Look at the pick on "love my old grove" thread.I am in the middle of the pole building.Those were 58 foot 2x8 trusses.I used a truss hook at the peak and we got along fine.The last pole building I done was a 62 foot truss,only they were 2x6 lumber! Very limber,made up a long "V strap" sling and we got the job done but they were still limber .The truss company says to use a speder bar at two points.I have to try something.Thanks for the help liebherr.
Just because we live in such a lawsuit-happy world, I have to wonder if there's some liability attached to using a spreader bar that hasn't been designed and signed off on by an engineer? (Thinking of the shop-built trench box we had on a job 25 years ago. It was a thing of beauty, and kept us from getting killed, but then I took the trench safety course, and learned that you can't use something like that. If it's not engineer certified, OSHA can hang you. I just have to wonder if the same is true of spreader bars and other such hardware?)
I know where you are comming from .but the fact is ,liability is part of the job.Its always been a lawsuit happy world.I just consentrate on the job and what has to be done at the end of the day.Thats why we have good operaters,welders,inspecters,insurance agents,and attorney's.
And most of the time, that will get you through. I just feel like I'd be remiss sometimes if I thought of a potential problem and failed to point it out, and then later somebody got in trouble for that very reason. Carry on... :thumbsup
c.y.a. NEVER shop build lifting devices unless you are a compotent and qualified engineer. all it takes is one carpie to get bopped with one piece of wood being lifted with your spreader to sink you. better safe than sorry.
does the truss company have anyone that would be willing to bare rent the applicable bar
I dont think the truss company has a spreder bar.I am not sure how they move them around at the factory.Its not a problem I have on a daily basis,but with people going with wider pole buildings its going to happen more often.I need to keep a spreder bar on hand for the wider trusses.The speder bars I have been around are made of pipe or square tubing.I think either one would work fine.Some of them are extendable ,whith one tube inside the other and pinned to different lengths.
If your comfortable using what you have then fine..just be sure to make a judgement call on knowledge not hast.. ... A legitamet spreader bar is a worth while investment from what your saying... with that said it may be wise to consider what you have ....draw up on paper a rough sctech of a master that you think would suit your needs and what capacity you would require ..,have an engineer redraw to spec and a fab shop to build it.... If its pricy ...start looking to government for info on one time small business money ,or things of that nature ,...the more question's you ask the better if there's money avaliable to you for these type's of things then take it,, ask everybody questions to help you get moving along and build a business Best of luck..
Thanks digger 242j,qball,and liebherr1160.all good ideas and advice.
25c; Been there done that. You may find the way you are doing it is as good as it gets. Remember the spreader bar will spin when you are swinging back for the next pick.This takes up time when cabling down till they catch the rigging to rehook. Where as nylons don't swing like that.12 ft nylons, 8ft 3/8 steel choker hooked in a basket sling to the nylon with shackle . Easier for the carpenters to unhook. just my oponion. mailtrain
How about this? I found it here: http://www.sbcindustry.com/images/publication_images/ttbcrane.pdf Here's another site that has a specific rig set up for lifting trusses. http://www.caldwellinc.com/rm4.html#wt If you click on the link for pricing, it tells you to call the inside sales department................:beatsme:beatsme
Thats what I what I am thinking about.Good information,Thnks Lugghead.
I know what you mean.That much more rigging swinging around.It takes 30 foot straps to do much good with the "v sling" arrangment off the hook to the truss.The straps are easeyer but I think the spreder bar is better on the trusses.Thanks for the imput.
Just finished with hanging sorta truss for a government job. Only its for a super secret thing on a base and the morons that were the iron workers were idiots. But the original drawing that liebarr did is the rightway for that application for your truss work too. Its the same thing idea. ONLY, i put the snatch blocks at the bottom of the speader bar and you must do it that way so everything renders right. Now your dealing with wood and i was dealling with aluminum 80' truss with the columns attached making a huge rainbow 60' tall and 80' wide. i used a 20' spreader bar that was built my me and no law in California anyway states it has to be engineered and signed off. otherwise all truss and everything would have to have designed in padeyes or some mechanical means of lift points. think about it. Most states require a compident person shal..... and so on. so the speader bar idea is the proper way to make it easy and not fold everything up. As far as making the workers pissed for all the rigging, um well the last time i looked, your the operator and if something should fail whos at fault? so dont listen to them, most of the time they are a few cards short as it is and always push the operators around to do stupid things. Dont push it and dont worry about them, let them know that your way is the best idea that sits right with you at that pick. Otherwise they run you around, you fail because your making them happy, and they go home to the family and you go to jail or hospital since the load im sure is almost in your lap. Im a young guy(30) and i dont take crap from anyone. So what ever idea you deside make sure you stick with it and just be comfortable with it. I wish i had pictures of the lift i just left for you, but they took my phone away because it had a cmaera on it. Seached my whole crane and darn near my butt hole. But i will offer my opinion that the spreader bar with short rigging to the hook and snatch blocks of the very bottom of the bar and then each side gets probably a 20' (steel) so it rolls, 1 on each end. you will have no problem and everyone is happy, and because your a rigging genius onsite everyone will see it and your a hero.
That sounds like an interesting job TheKid.I would think the problem is the same with steel,aluminum,or wood.the longer the truss ,the more limber it gets.I just noticed a very important detail.Everyone look at the k-truss in the picture on post #14 by lugghead.The chokers from the speder bar to the truss angle toward the center of the truss.This would keep the truss stable from folding.I am going with my original idea for the speder bar,but I think the angle on the chokers is the fix for the problem.
We have found it quite difficult to find an engineer to design something to build. Most engineers want to work for a manufacturer where they have control over all aspects of the design in house. We tried to find an engineer to design and stamp plans for a crane runway that we were going to build. Nobody would do it because they weren't in control of the construction. Apparently engineers can still be liable for failures of equipment not built to his plans or to standards.
http://www.tandemlock.com/ If you going to build one this company has all the proper fittings and design criteria to go by. I have an resident P.E. in house and I still using building a spreader in house as a LAST resort. And every spreader bar that is a load carrying member is sent out for testing and certification before being put into service.
I'm currently setting 63 foot long arches (concrete) If you can picture this.....From thr hook block down there is 30 feet of triflexes(2 of them).........At the bottom of each of them are snatchblocks with 60 foot wire ropes going through them...at the bottom of those, one end is attached near the end and the other leg goes to near the peak.....this equalizes the load and it hangs perfectly square......So there are 4 hook points on the arch using the 4 ends of the equalizer legs ....I will have pics this week if that was too confusing..
This thread is old, but, :my2c I used to build a few Pole type truss buildings. We sat several 80' spans. I simply tied a 6" x 6" post x 30' long or so, onto the bottom chord of the truss with a few small lengths of rope. Used 20' spreader cables, and it lifted straight. After setting the truss, and bracing it, we'd let the post back to the ground. I didn't have the money for a spreader bar.
Your right ..I asked about rmoving the center colum from my house ..I had drawing's roughed up and showed our in house engineer ....Though he agreed and added additional tip's ..he wouldnt draw it up and stamp it for me to hand over the the city .. Simply because .. he couldnt do daily inspections and be there when major components were being taken out or installed .. Not that he didnt trust me ..he just had to witness the whole thing ..in case that "in the event off " thing came to be ..he had documentation ..
Came across this while thinking about lifting lugs and found it very helpful. Good reading on a day when its -20 F and the superbowl is still a week away! http://files.engineering.com/downlo...4ed5-ba86-80a97bb5481e&file=Lifting_Beams.pdf
I've got a good one for you riggers. I'm demolishing a grain storage building to make room for new round storage tanks. This building is 100' wide clear span, 21' eave height with a 6:12 roof pitch. All steel construction, and massive steel compared to typical pre-engineered buildings. The rise in the roof is 300" or 25'. On standard pre-engineered buildings with 60-80' of clear span and relatively flat roofs, I simple fabricated a bracket that bolts into the purlin bolt holes. The holes are typically on 5' centers across the building, and are 1/2" in diameter. I'm trying to tell my guys to take it down in two pieces as we have two rigs there. They're all wanting to take it down in one piece. I can see it swarming their a$$es. Even if it comes down straight and true, whenever they start to lay it over, it could buckle. Ideas? Do I hold my ground and force them to take it down it two pieces?
Thanks for posting that handy info, I've been looking around the web for something like that but to no avail.
http://www.engineersedge.com/wwwboard/posts/13528.html more info and a good design using 2 pieces of channel back-to-back.
Ive put them up in one piece...wobbly ..need to be steady ,and have the wind on your side ..On the way long 150ft ones we use two cranes and put them up in one piece.. the trick to keep it from buckleing ..was to get your spread of the center of the beam ....100foot .. that's a three piece beam ..right?.. where the web on the two outter pieces meet ..thats where the choker's went.. ..Now if its a two piece ..hence two 50 ft sections ..20feet from the center each side with a choker would get it down and you lay it right over .. The idea is that the rest of the beam out side the chokers will cantilever the center and it wont buckle .. Something tells me your gonna say its an odd ball purlin though .. But is it a purlin or a truss .. Worst case take it down in one piece with two cranes .. Did a Airplane hanger with 4 cranes ...
It's a 4 piece beam. The purlins are 8" Z-sections. I like the idea of 2 cranes, one pick. Thing is proprr placement of the rigging. I'll get it right at least by the second one.
Grab a picture ...would like to see for myself ...the truss ..beam ..purlin ...LOL:drinkup ...show me the steel!!! ..
I've looked all over my PC for pics, but haven't found any. I'll see what I have at work on Monday. I'm not going out in the cold in my Scoobies for a pic today.
A couple of photos, as promised.
A couple scenario's Two cranes to take one down .. You could do it with one ..and tail it out with a pair of fork trucks ....I wouldnt chance just laying it down with one crane .. another option ..If you think the steel will hold ..is to guy back the columns and pull the center ..then the ends ..then the columns Ohh a few Highway barriers make great anchors .. a few chain falls or Turfor's ..reall handy.. What ever you do ..it looks like fun :drinkup
I'm thinking a two crane job. There's already two cranes there. Thing about pre-engineered steel... The Z-Purlins bolt to the top flange of the rigid frame with two 1/2" bolts on 3" centers. Everything is symytrical from center. In other words if you pick apair of holes 16' from the center on the left slope, the right slope will also be exactly 16'. Plus with the 1/2" hold dead center of the top flange, a clip bolted with a clevis connection holds the frame exactly plumb and straight. Chokers wrapped around the frame, with one off center slightly, makes the frame uneven, and quickly lays over, especially 100' widths. The worst part is the top flange on these pre-engineered buildings are only welded on one side. I'd hate to pull a flange off. Another thing...1/2" bolts...marginal at best. Definately would be 1/2" high strength structural bolts. Four 1/2 bolts on each side would be better. BUT..with two cranes, I KNOW it'll be ok. After we get one to the ground, we may rig different ways to see if one crane can do it. If it fails from 0' above ground is much safer than 50' above ground.