Educate Me on Trolleys and Underhung Hoists

For those that don't know, I'm going to be building a building here soon.

I'd like an overhead crane, but that's not gonna happen. The next best thing I figure is going to be a traveling gantry that runs down the shop on a track.
Yes I know this isn't the best solution and yes I know the issues about building something like this. At this point, it is only theoretical.

I know where there are some W33x141 beams, but I was under the impression that W flange beams weren't supposed to be loaded on the flange like it would be with a trolley, thought you were supposed to use an S flange for that.

But then I found this; http://store.americancrane.com/Asset/Crane-Comp-Drawings-and-Spec-CSL-1002-0407-opt.pdf
And in their charts, they are using W flange beams, and Goggling some of these questions leads to results to trolleys made for both S and W sections.

So what is it? Can a W flange be loaded with an underhung trolley or not?

What I would like (and at this point, it is theoretical) is a 35ft span 5-7.5 ton capacity. I figure these numbers are realistic because the PDF says they use W30x132 (with a 18x47.5 cap) for a 38ft span and a 10 metric ton load.

Thanks for any and all info.

5-7.5 tons is nothing to cock around with. You need an engineer, or another plan.

Yes I built smaller cranes using a wide flange beam at a crane shop I worked in for 11 months. All the wide flange beams had a large channel stitched to the top flange, channel leg down. By itself the beam was not rigid enough. The channels were at least 12 inches wide and sometimes wider.
The winch ran on the bottom flange.
These were engineered beams. To be safe you need an engineer.
There are some firms that supply end trucks, winches, and all the cabling with controls then all you do is weld up the beam with end frames with an engineer looking over your shoulder so that you do it right.
I have seen welding firms make their own shop crane. There was no engineer in sight just a few hand sketches... scary.

alskdjfhg:

Yes, crane trolleys can run on the bottom flange - it's done all the time. The W33x141 section appears to work fine for your load/span: you'd be using about 50%of the available strength and it would deflect about 3/16". (Note these numbers are without the cap beam.)

BUT: A few other issues need to be addressed. First, the local bending of the flange would need to be verified. This is a bit of a tricky calculation (uses yield line theory.) Second, the beam needs to be checked for lateral torsional buckling. Also not a simple calculation. My advice is to hire a structural engineer to check your design - this is what they do every day. In addition to the issues above, he'll look at the end bearing and support conditions. (There's a 11,000 lb reaction force at each end that will need to be dealt with and a foundation designed for that.) Lastly, he'll need to design the support system to deal with the lateral forces. Cranes generate substantial horizontal loads when a traveling load is stopped suddenly. All of these issues need to be addressed - its the law. These design documents are normally required for your building permit application.

Regards.
DB

I've hired an engineer to design beams for me in my house, shop, and gantry cranes I've built. It's not that expensive, like $250 for a simple beam design to $1000 for a system with load reversals and column details.

Thats out the door with signed, stamped drawings by a registered PE.

Gravity's a cold, very unforgiving bitch.

And keep your eyes open for cranes. They show up all the time on odd places like Craigslist.

Chip

Im a firm believer in gantrys... I have used several over the years. Im down to 1 right now looking for the right second one. They just seem to fit for me. Im not sure about your situation. But a rolling gantry is a very usable tool.

On the other hand I have seen some over head cranes on craigslist that seemed to be a bargain.
Here is one in Sioux falls.
https://siouxfalls.craigslist.org/bfs/4813590344.html
Or maybe
https://cedarrapids.craigslist.org/hvo/4821360895.html

Over head cranes seem to be one of those things that command a bunch of money new and are just too good to scrap when used...You might spend some time on Ad Hunt'r - Search ALL of Craigslist? and more! and find something...

One thing I do know for sure... Keep on the lookout for a good quality manual chain hoist. Even if you find the best electric hoist on earth.... they just dont give you the fine touch a manual hoist does. While at a plant a few years back They didnt use the over head crane because the movement was too aggressive. Any button seemed to move the crane a couple feet. A 5 ton manual chain hoist hung on the hook made that machine very usable.

alskdjfhg said:

I know where there are some W33x141 beams,.

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Having cut and welded (and erected) WF beams over 100 lbs/foot (I still have some 27 wf 110 out in my field),
I've got to wonder just what are you planning on hanging these on ?

alskdjfhg said:

For those that don't know, I'm going to be building a building here soon.


What I would like (and at this point, it is theoretical) is a 35ft span 5-7.5 ton capacity. I figure these numbers are realistic because the PDF says they use W30x132 (with a 18x47.5 cap) for a 38ft span and a 10 metric ton load.

Thanks for any and all info.

Click to expand...

OMG. Take the advice ewlsey gave in post #2. No matter what you do I'm sure you'll need to get it approved. Lifting 5 to 7½ tons isn't to be taken lightly and that isn't intended as a joke.

https://www.youtube.com/watch?v=a_IzvbiyX9w

The footprint of a gantry that size is going to be quite large and, nothing can be placed along the run. That is a lot of dead space. You also realize that a 32" high beam and roughly 2~3' tall hoist is going to require 20 foot eaves to be of any practical use. To unload a trailer with a full height load even 20 feet is marginal. Instead of a monorail design consider a double rail bridge, it greatly reduces height and adds stability.

I concur with the others who suggest a used bridge crane, I have two crane ways with 4 bridges, 3 and 5 ton. Things start getting really massive above 5 tons.

Steve

I'm not really impressed with the 5-7.5t desired capacity, as I am the 35' span. A 10T load can be carried by darned near ANY decent beam when the span is only 2 inches... but when you start making the reach, it's a different situation.

Simply because there's lots of gotchas, and variables galore, I won't even make suggestions on any aspect of the OP's ideas, but I will advise that there are MANY different failure conditions that need to be considered... columnar loads on the vertical as well as horizontal axis, distribution of loads to columns, contact load on the flanges, and deflection of the running surfaces.

I think the term 'old-school' would be inappropriate, but the engineer that I've found best at mentoring me with regards to structural loading in cranes once pointed out that one could design a crane system that suited all safety requirements just fine, but 'wouldn't work worth crap' because the amount of deflection that would be acceptable for a safety factor calculation, would be seemingly innocuous in it's realm, however, would not lend to proper motion of the crane's elements... meaning... the support beams bowing under load, would make the trolley want to roll downhill towards the bow... and not 'climb' towards the support points.

Hence, he said something to the effect of "Plan on overbuilding it so much, that it will simply NOT indicate any noticeable deflection, under extreme overloads, and it'll work fine".

And this guy didn't go to college for an ME... because he was doing it prior to WW1...

Most industrial cranes are built to a deflection limit. Bridge cranes are usually between 1/500 and 1/1000 of the span. Jibs are more like 1/360 of the beam length. I think you would find that a beam designed for that kind of deflection is well below any stress limit in bending and no even on the chart for shear.

We've got a 12.5 ton bridge crane with a span of about 35 ft that my dad bought a long time ago because it was dirt cheap and he had his own cranes and riggers to remove it and his own tractor/trailer to transport it. Never have installed it, and it just keeps one section of the yard from floating away

Anyway, its a humongous thing. Almost 12 ft wide when loaded lengthwise on a flatbed trailer. Just guessing at the weight, but I'd say at least 20,000# and maybe more. I remember when we removed it the supporting columns for the beams it ran on looked like something you'd find on the lower floors of a 40 story building. Just to purchase, fabricate, and erect the framework of steel necessary to support that thing would cost a small fortune. On top of that, all the electrical stuff necessary to supply power to it as it moves would be another medium size fortune unless all that stuff happened to come along with a used unit.

Thanks for the replies guys.

I'll try to reply with more detail later.

I bought a 2 ton Budgit bridge crane kit when I put an addition on my shop 10 years ago. The kit specified S beam sizes for given spans, I followed guidelines for a 25' span and built my addition a little wider with a crane way down it. The bridge crane framework supports the roof, I overbuilt it, and the whole project wasn't too difficult. I use it all the time as it doesn't take much to get to where I don't want to lift something myself. Bridge crane is manual, with an electric CM hoist.
I have other equipment to lift and move much heavier things around, but having a small crane built into your workspace is well worth it.

Figure you will loose at least 6' of height from your eve height to your maximum under hook height, even more if you go to 7 1/2 ton. Consider a jib crane. Freestanding with a sleeve installation won't take up much room. Position it for 360 swing. And/or get a upright or two on your building upgraded to jib crane rated. 20' x 2 ton won't add much to the cost.

I'm going to swag you are going to be into $10-15k to get this off the ground (so to speak).

A pesky problem with bridge cranes and travelling gantries is that they interfere with stuff like ceiling fans, cords and conduits run vertically to overhead outlets, and garage door tracks.


I think Thermite has the best idea, pour a good slab, and use skates and a forklift. I've supervised a project where we moved 2 different ~20k rack handler under/over conveyors thru the plant and into place with 2 skates and an 8k forklift. Very calm event. It did have some advantages like a heavy structure a foot off the floor which could be used for lifting, etc. The first one took a mobile crane and a forklift to remove from the semi truck, the second a larger mobile crane.

You have to ask yourself how often this is going to be used. The span is sort of an exponential thing in terms of structure and cost. Its cool to emulate a shipyard but I promise they have a larger budget than you do.

I think I'd try to go down more to about 9ft span, this is going to be appropriate for any gooseneck or semi trailer with an 8'6" width + rub rails. Fixed gantry. Casters just to move the bare gantry & hoist, use your forklift to bolt on and off caster brackets, one side at a time. In other words, just use it as a static structure to set down the machine in question on skates, and move it into position with your forklift. You might only have 2 skates working (the other end is a forklift), so its then a matter of setting each end down with overhead rigging and or enerpac flat cylinders, spreaders, toe-jacks, and prybars.

The other question involving large machines, is: can you really lift them from a single pick point? Or does it make more sense to have a double set of gantries and be able to lift from two points....

The points raised above about levelling and heavy minimally-deflecting structures are all about the runaway possibility of a heavy load, very difficult to stop once it gets moving downhill, as slight as it might be. Very difficult to get it moving back uphill also. A bridge crane is sort of like a very large surface plate, the runway rails are typically aligned in track width and level within 1/8" over the entire span. That takes careful erection and adjustability built into the design so a group of people can monkey around with alignment until its inside those specs. There are laser leveling tools these days which can help a lot, but its still not a trivial exercise. I still hold onto the dream of building a 3T bridge crane, I have many components and a powered trolley hoist for such. But the reality is that they will probably still be in the parts bin and unlikely to ever build the structure.

Another thought for a bridge crane integral with a steel framed building. The building company will guarantee your building to start to leak after some amount of crane usage. The deflection of the columns as the bridge passes as well as the racking from starting/stopping a load will work over time to elongate the fastener holes. I've been told this by builders representing two different building manufacturers. Either will furnish a building with crane load rated columns.

The "Open Air Museum" Makes Chips

matt_isserstedt said:

The other question involving large machines, is: can you really lift them from a single pick point? Or does it make more sense to have a double set of gantries and be able to lift from two points....

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Funnily enough, working on building one (out of two) of those yesterday.

Building The Gantry Cranes Photos by mebunting | Photobucket

Drilled the holes in the 1/2" thick 6" wide flat stock with the Wells-Index. Then using two conveniently located holes already in the beam and some Kant-Twist clamps, the plate was secured to the beam. Heated it with an O/A torch and used a pipe wrench with a cheater to bend the plate until it was reasonably close to 90 degrees. I was originally going to layout the holes that needed to be drilled on the I-beam, that's why the layout dye, but ended up working off transfer punch marks.

Picked up the beam with the W-11, put it in the vice in the 2MH and started drilling. Wasn't thinking and only brought one vice, so there was some chatter and deflection.

Need to drill aprox. 80 more holes, make some braces out of pipe (PH6 tubing) and it's done. Can't wait to have the 5CK running, the larger table would have been nicer to work with and the rear controls would have this job so much easier.

A mag drill would be an enormous time saver on that work. If you are going to do a red iron building a mag drill will be indispensable as well.

Not sure what the brackets do but, I wouldn't trust them as is on any significant lifting device. The angles should have gussets to keep them from moving around. The weights that you are talking about lifting are not trivial, these are not a 1000 pound engine, one little hick-up could impart a G or more of force on your load. The potential energy in the gantry is huge, you really want to build it to a load factor of 2 as a bare minimum.

Steve