Extra I-Beam, gantry build ??

[Buickspec6231]

In my recent home building experience, I have acquired an extra 24' of W14x34 I-Beam. I needed 26' for my ridge beam, but had to buy the whole 50' length.

I have wanted to build a gantry for a while, and always found that the price of I-beams on the second hand market mirrored new prices, so I never dove in.

Does anyone have a good program/website/knowledge base to help determine what my single point load capacity of this beam would be? I'm not looking to get anyone's name to put this in writing. I'm not an engineer, nor are many of you. For calculation purposes I plan on a 20' span between two vertical supports. I'm not concerned about caster or chain hoist capacities at this time. That is another discussion for another day.

I'm not the strongest in math when it comes to calculating force and beam deflections. I'm also not expecting anyone to do the calculations for me. Just looking to be pointed in the right direction.

This may not be the right beam for this project. But I already own it. Trying to see if I should keep it or sell it off.

 

[Ike Carlson]

How wide do you want your gantry and how heavy of a load do you want to lift?
I can run a few rough numbers for you.

 

[nadogail]

More than 20 years ago I asked a manufacturer for their catalog and it had the dimensions and specifications of the mobile Gantrys they offered.

I don't recall their name but they had a Hippo in their advertising.

That may be of some assistance in finding the information you seem to be seeking.

 

[Ike Carlson]

Here is a rough idea of what to expect. I just plugged in some numbers for your beam and assumed it would be 10 ft long. Your biggest problem will be making it stable. Gantry cranes need excellent lateral support or the legs will fold. I am not responsible for the use of this information.

I used 10,000 lbs as an extreme example.

What you are looking for is stress and deflection. The highest stress will be directly under the load across the bottom of the beam. Center load is the worst so thats what I used. You have a safety factor of at least 6. The beam will bend .0365 inches with 10,000 lbs on it. Building the rest to hold that weight would be very costly, if you could find the parts.

 

[WNYflyer]

https://www.steeltools.org/industrial.php

See Monorail Spread Sheet by Alex Tomanovich


View media item 105023

Use at your peril and not assuming this is correct but should give a rough idea of the approximate capacity. Assumed material as ASTM A36 Fy=36,000 psi = 36 ksi. If new material them most likely ASTM A992 Fy=50,000 psi = 50 ksi and adjust input accordingly. Since i don't always trust the spread sheets if I haven't used them in awhile I typically do the calcs by hand to get the warm fuzzies that the spread sheet is correct. It goes with out saying that the spreadsheet is intended for professionals who understand the input and I will point out unbraced length is the one item most non-professionals don't understand to potential catastrophic affects.

Note 1 kip = 1000# in my world

 

[ZRX61]

You could probably hang a crew cab dually from it...


Maybe someone needs to come up with a formula for hanging crew cab duallies. The CCD (or F350) Formula that covers spans & beam dimensions etc.

 

[Ike Carlson]

It goes with out saying that the spreadsheet is intended for professionals who understand the input and I will point out unbraced length is the one item most non-professionals don't understand to potential catastrophic affects.

Yes, unbraced length gets a lot of builders on trouble. I will add to your comment that I beams and channel fail in similar ways and most people don't understand that they will twist before they break/fold in most cases. They are unlike square beams where the beam fails in one dimension. It will be important that he brace the ends of the beam to give it as much resistance to twisting as possible.

 

[Ike Carlson]

You could probably hang a crew cab dually from it...


Maybe someone needs to come up with a formula for hanging crew cab duallies. The CCD (or F350) Formula that covers spans & beam dimensions etc.

You could, if it was built correctly. My original calculations were for 20,000 lbs.

 

[MoonRise]

A W14x34 beam weighs 34 lb/ft length.

That beam could support a pretty good load,

IF

THE

SUPPORT

STRUCTURE

IS ALSO DESIGNED

TO

SUPPORT

THE

LOAD.


Single-point loading is pretty bad for a beam. That W14x34 beam at 20 ft long could only support ~1000 'safely' at the center of the span if single-point loaded.

Spread the load over a 4-pair (yeah, 8 wheels total) wheel trolley with 12" between the wheels along the length of the beam (to spread the load away from a single-point condition) on that same 20 ft W14x34 beam and the beam can 'safely' support ~5000 lbs.

NOTE: those numbers, although real, do NOT include the mandated/required safety factors if you will EVER be underneath that load. Like working the trolley and chainfall while lifting the load.

Further note: The support structure must also be able to handle dynamic load conditions (load sway, load bounce, trolley and load motion along the beam, etc).

And the floor has to be able to withstand the caster/wheel loads.

Doable? Maybe.

Easier to just buy a gantry crane already designed and engineered and made? Yup.

random google search results for "gantry crane"

https://www.spanco.com/products/gantry-cranes/

https://www.lkgoodwin.com/more_info..._tripod_cranes/gantry_and_tripod_cranes.shtml

https://www.gorbel.com/products/cranes/gantry-cranes

https://www.harborfreight.com/1-ton-telescoping-gantry-crane-41188.html

 

[MoonRise]

Gorbel gantry crane brochure:

https://www.gorbel.com/docs/default-source/brochures-and-fliers/gantrybro.pdf?sfvrsn=d7660b19_15

As an example, their 20 ft width (actual usable width between the uprights is listed as approximately 18 feet, varies a little depending on exact lift weight rating) adjustable-height gantry crane for a 3 ton rating uses a W16x45 beam, for a 1 ton rating uses a W12x35 beam, and a 5 ton rating uses a W24x84 beam.

 

[ZRX61]

You could, if it was built correctly. My original calculations were for 20,000 lbs.

I think the CCD Formula should be based on 8500lbs (to include a small fudge factor)

 

[readhead]

Some pretty smart guys here but I’m still pissed at the guy that made you buy 50’. I have always been able to buy beams in 5’ increments.

 

[Buickspec6231]

Wow. Much more of a response than I was expecting. Thank you all. Yeah, Its probably just a pipe dream, but I figured I'd just kick the idea around. I just keep thinking how awesome a 20' span gantry would be in the shop, but in all truthfulness it be way too much. I really want a 3 ton capacity. My old man has a few 30's era Mack trucks and I have an 80's era backhoe and boats that a 3 ton gantry at 12-13 foot tall would be helpful. Maybe we can make a 12ft wide trolley style instead and have a narrower but more capable crane? Just take the beam and cut it in half. I'm definitely going to do more calculations and planning before I do anything. I work mostly alone and take safety seriously. I'm not going to risk my life or anyone elses over a poor design.

Some pretty smart guys here but I’m still pissed at the guy that made you buy 50’. I have always been able to buy beams in 5’ increments.

Yeah, I wasn't too happy about it, but what was I going to do? I had a guy quote me a slightly higher price, including the delivery and no extra material. I didn't see the point to paying more for less.

 

[Ike Carlson]

One last tidbit...

Doubling the length makes it bend 8x more

 

[cvairwerks]

I just priced a Vestil gantry, 4 ton capacity with a 15’ beam. Adjustable height, up to 14’ under the beam. About $3100 delivered to my door.