Lift using two chain hoists

[marka12161]

I'm going to be lifting a 6,700 lb cataloge weight machine off of a flat bed equipment trailer. This is well withing the capacity of my H beam but just a tad over the rated capacity of my 3 ton beam trolley and chain hoist. I know these things are probably designed with a 2X or 3X safety factor but i'm one of those guys that believes ratings exist for a reason. Anyway, i have a second trolley/chain hoist set up rated at two ton. I'm considering mounting both on the H beam and using both chain hoists and a spreader bar to lift the machine. In theory, each trolley/hoist would carry half the load assuming the spreader bar is maintained level. In this configuration, both trolley/hoists would be well withing their rating. Is their some not-so obvious problem with this plan or am i over-thinking it?

 

[Ox]

#1 obvious reason would be daylight under the beam.
If you have the shut-height to werk with - should work fine.

As I was reading it - I was thinking spreader bar if using 2 hoists.
If not a bar, then I would go with the one hoist only, unless the machine is like a lathe or something that really works better with 2 anyhow.

If it turns out badly - we will be requiring pics - so keep that in mind!


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Think Snow Eh!
Ox

 

[john.k]

You will have no problems.........better if you can find a helper to work one hoist .........I wouldnt bother with a spreader ,just hook each hoist to one end of the machine........nothing happens very quick with a chainhoist .

 

[Rob F.]

Like John said, just hook each hoist directly, no spreader needed.

 

[Ox]

Are you two saying that if he has one point that he wants to pick from, that he should hook BOTH hoists to the same point? If so - that is a super way to have all the load on one or the other, and seldom ever both at the same time. In that case, better to be on just the one hoist.


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Think Snow Eh!
Ox

 

[Phil in Montana]

It would help to know what the machine is...BUT if you can hook it in 2 spots and keep the machine level on the lift and the drop no problem, it is done all the time, but if it gets out of level one hoist would hog the load, maybe to overload...Phil

 

[marka12161]

It would help to know what the machine is...BUT if you can hook it in 2 spots and keep the machine level on the lift and the drop no problem, it is done all the time, but if it gets out of level one hoist would hog the load, maybe to overload...Phil

It's a milwaukee 2K mill. The "Spreader" i would use would be very short, maybe 2 ft long just enough to make sure the hoists are sharing the load. I would attach a bubble level to the spreader. I would have one person on each chain hoist. I move a a glacial pace. Something about an old Bull...

 

[michiganbuck]

OT: 6,700 lb catalog weight machine off of a flat bed.

That is not much weight, likely a guy with a boon/lift truck will give you a 100bucks an-hour rate.
When in doubt call in a professional.

 

[Milland]

The thing I worry about with chain hoists is the need to be near the load as it lifts. I've used multiple electric cable winches simultaneously for larger, spread lifts, and those have pendants that the operator(s) can use at a distance, so giving some protection if the lift goes wrong.

Have clear instructions if another person's helping you, and try to determine where the safest place for the oporators to stand will be. A chain lift will work with some offset to the actuator chain, take advantage of that.

 

[guythatbrews]

I"m assuming you intend two lift points equidistant from C.G.

As long as the center of gravity is centered between the lifting points the load will be shared even if out of level. The problem is where exactly is the C.G.? Easier to see with a mill than a lathe.

There is more chance of unequal load the closer the lifting points are together. Imagine 1" and 2" from C.G. versus 12" and 13" versus 12'-0" and 12'1". In the 1"-2" example the 1" hoist will lift twice as much even if level. For 12"-13" difference is a little less than 10%. Either way you will be well inside the capacity of your hoists.

You don't need a spreader unless you get crazy out of level causing the bottom hooks to get closer together. That will create a force sideways force on the top hooks.

 

[Milland]

I do think a spreader is a good idea, as among other things it helps prevent the two trolleys (presuming the hoists aren't hard-mounted to the beam) from being able to "roll together" if/when the beam bends under load.

If the two attachment points on the machine are at a distance and there's not a long drop between hoist and AP then the machine itself can be used as the spreader.

 

[Ox]

It's a milwaukee 2K mill. The "Spreader" i would use would be very short, maybe 2 ft long just enough to make sure the hoists are sharing the load. I would attach a bubble level to the spreader. I would have one person on each chain hoist. I move a a glacial pace. Something about an old Bull...

Well, make sure that you have steel toes on and it'll all be fine.


-----------------

Think Snow Eh!
Ox

 

[tailstock4]

I'm going to be lifting a 6,700 lb cataloge weight machine off of a flat bed equipment trailer. This is well withing the capacity of my H beam but just a tad over the rated capacity of my 3 ton beam trolley and chain hoist. I know these things are probably designed with a 2X or 3X safety factor but i'm one of those guys that believes ratings exist for a reason. Anyway, i have a second trolley/chain hoist set up rated at two ton. I'm considering mounting both on the H beam and using both chain hoists and a spreader bar to lift the machine. In theory, each trolley/hoist would carry half the load assuming the spreader bar is maintained level. In this configuration, both trolley/hoists would be well withing their rating. Is their some not-so obvious problem with this plan or am i over-thinking it?

I’ve used two hoists like that although usually one or both are electric. Sometimes I will use a forklift and a hoist with a remote pendant to the hoist around my neck which allows me to sit on the forklift. Sometimes I would use a spreader bar if lifting from a single point on bottom or if I needed to rotate the load.

One thing about spreader bars is that there is usually two attachment points on top allowing for a long bridle to a single point which provides stability. Recently I’ve seen on YouTube someone who did not have enough room for the bridle simply eliminate it and weld a single pad eye on top in the middle. Depending on where and how the load slung underneath is attached (in this case at the bottom), this can create a teeter-totter. I don’t think they were ever aware of this as the load didn’t somersault because of the close proximity of the chokers to the load. It couldn’t rotate enough. Just lucky, I guess.

 

[Superbowl]

You are over thinking and over complicating this and that can lead to problems. One hoist is fine. Just use a simple chain wrapped around the beam as a spotting secondary emergency safety stop.

 

[Rob F.]

Are you two saying that if he has one point that he wants to pick from, that he should hook BOTH hoists to the same point? If so - that is a super way to have all the load on one or the other, and seldom ever both at the same time. In that case, better to be on just the one hoist.


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Think Snow Eh!
Ox

No, I was following John's lead and suggesting one hoist on each end of the machine, two separate lift points, each will have about half the weight of the machine.
This is "assuming" the machine has two pick points.
But now we know it is a mill and is probably easiest with one central lift point, would have been nice to know the machine in the opening post....

 

[marka12161]

No, I was following John's lead and suggesting one hoist on each end of the machine, two separate lift points, each will have about half the weight of the machine.
This is "assuming" the machine has two pick points.
But now we know it is a mill and is probably easiest with one central lift point, would have been nice to know the machine in the opening post....

Yes, a vertical mill, once central pick point. I apologize for lack of clarity.

 

[marka12161]

Thanks to all who weighed in on this. I know what i need to do. The hardest part will be getting the second trolley mounted on the beam 16ft up.

 

[Milland]

Thanks to all who weighed in on this. I know what i need to do. The hardest part will be getting the second trolley mounted on the beam 16ft up.

Not a problem, use the first trolley to lift you and the second one up to the beam.

 

[Ox]

No, I was following John's lead and suggesting one hoist on each end of the machine, two separate lift points, each will have about half the weight of the machine.
This is "assuming" the machine has two pick points.
But now we know it is a mill and is probably easiest with one central lift point, would have been nice to know the machine in the opening post....

IDK why either of you would have ass_u_med that?

From what I read - it seemed like he wanted to pick from one point, otherwise I wouldn't have expected him to have asked the question in the first place.


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The old "Blame it on the guy before me" trick eh?
Ox

 

[Phil in Montana]

Go shopping on cl or fb chain hoists show up often and are cheap, just buy a 3 ton...Phil