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Are there any data must be added to spreader beams drawing attached?
- Thread starter Alaazaki
- Start date
SlideRuleEra
Structural
Alaazaki - I suggest making all the lifting lugs one size (the largest one, Detail 1). This is to allow all the pins to be the same size (large). During use it is very easy to get pins mixed up and use a "small" pin where a "large" one is needed.
Check to see is A36 steel is available for the shapes needed. Using A992 steel is likely more common.
Check to see if welding A572 steel lugs to A992 (or A36) steel beams is advisable.
Safe working loads are given in "tons". There various definitions for "tons". Clarify which is intended or use another unit.
![[idea]](/data/assets/smilies/idea.gif "[idea] [idea]")
![[r2d2]](/data/assets/smilies/r2d2.gif "[r2d2] [r2d2]")
Check to see is A36 steel is available for the shapes needed. Using A992 steel is likely more common.
Check to see if welding A572 steel lugs to A992 (or A36) steel beams is advisable.
Safe working loads are given in "tons". There various definitions for "tons". Clarify which is intended or use another unit.
thaidavid40
Structural
On the data line for the safe ratings, add the lifting standard to which this is certified (in the USA, it is ASME 30.20-2010).
Dave
Thaidavid
Dave
Thaidavid
Alaazaki:
I generally agree with SRE, with a few exceptions or additions. I think you should really try to simplify this lifting beam system. You may be trying to do too much, too exactly in dimension and location of lifting lugs, etc., with one system, which could lead to some complexity and confusion. That is..., what set of lifting lugs to use, when and for what load. You might want to mark matching sets of pin holes or lifting lugs, from left to right as A, B, C, etc..., C, B, A on each end of the beams, so it is easier to match them up in use. You should also stencil the cap’ys. at each lug or lug set in some unambiguous way. When you stack layers of lifting beams and slings as your system contemplates, you can end up with a system which is tall enough to need a crane with a longer boom and larger cap’y. To eliminate the Ropes (2), you might consider pinning beams Group (B) directly to the underside of the beams Group (A)
I would use lifting lug Detail (1) on the tops of the two Group (A) [Level (A)?] beams, and then all the lifting lugs on the undersides and below these two beams would be Detail (2) lifting lugs, for the reason SRE suggests; namely same size pins and shackles, ease of operation, and saving any confusion. But, better yet, on the undersides of all the beams I would use one continuous pin plate, 30mm thick (or some such), with pin holes at 6" or 8" o/c, on each end of the beam. This leads to a very clean welding detail to the underside of the beams, long fillets on each side of these pin plates. The many welding starts and stops on each side of the many lifting lug plates are the areas which are most susceptible to welding defects or cracking problems. The pin holes should be drilled or milled and should have a slight chamfer on the corner/edges on each side, to minimize nicking and cracking.
The primary problem with welding the A36 beams to 50ksi stl. pls. is that, while you are inclined to use welding materials which match, or slightly exceed the 50ksi material, you should really design your welded joints using 36ksi as an allowable stress. This is due to the weld metal mixing during the welding process. Otherwise, the welding of A36 or A992 materials to A572 pl. should not present any problems. You might use welding material compatible with A36, but you can’t use 50ksi as an allowable weld stress. I do understand the want for using A36 for the beams, since the primary beam issue is buckling, and the lower design stress makes some sense. While the higher yield and bearing stresses of the A572 pl. improves the design of the lifting lug pls.
I generally agree with SRE, with a few exceptions or additions. I think you should really try to simplify this lifting beam system. You may be trying to do too much, too exactly in dimension and location of lifting lugs, etc., with one system, which could lead to some complexity and confusion. That is..., what set of lifting lugs to use, when and for what load. You might want to mark matching sets of pin holes or lifting lugs, from left to right as A, B, C, etc..., C, B, A on each end of the beams, so it is easier to match them up in use. You should also stencil the cap’ys. at each lug or lug set in some unambiguous way. When you stack layers of lifting beams and slings as your system contemplates, you can end up with a system which is tall enough to need a crane with a longer boom and larger cap’y. To eliminate the Ropes (2), you might consider pinning beams Group (B) directly to the underside of the beams Group (A)
I would use lifting lug Detail (1) on the tops of the two Group (A) [Level (A)?] beams, and then all the lifting lugs on the undersides and below these two beams would be Detail (2) lifting lugs, for the reason SRE suggests; namely same size pins and shackles, ease of operation, and saving any confusion. But, better yet, on the undersides of all the beams I would use one continuous pin plate, 30mm thick (or some such), with pin holes at 6" or 8" o/c, on each end of the beam. This leads to a very clean welding detail to the underside of the beams, long fillets on each side of these pin plates. The many welding starts and stops on each side of the many lifting lug plates are the areas which are most susceptible to welding defects or cracking problems. The pin holes should be drilled or milled and should have a slight chamfer on the corner/edges on each side, to minimize nicking and cracking.
The primary problem with welding the A36 beams to 50ksi stl. pls. is that, while you are inclined to use welding materials which match, or slightly exceed the 50ksi material, you should really design your welded joints using 36ksi as an allowable stress. This is due to the weld metal mixing during the welding process. Otherwise, the welding of A36 or A992 materials to A572 pl. should not present any problems. You might use welding material compatible with A36, but you can’t use 50ksi as an allowable weld stress. I do understand the want for using A36 for the beams, since the primary beam issue is buckling, and the lower design stress makes some sense. While the higher yield and bearing stresses of the A572 pl. improves the design of the lifting lug pls.
The ones I've designed, either OSHA or the ASME standard required a nameplate on the beam and I believe some kind of warning sticker- if that's required note it. If it must be tested prior to use, include details somewhere.
On those lugs right together (assuming the drawing is to scale), I'd be inclined to combine them into one long lug with two holes.
If I've designed the holes/lugs for a specific shackle size, I'll note that.
On those lugs right together (assuming the drawing is to scale), I'd be inclined to combine them into one long lug with two holes.
If I've designed the holes/lugs for a specific shackle size, I'll note that.
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