Any engineers on here?

[billybob_81067]

I'm needing a good website with some info on what kind of loads different sized beams will take. We need a couple of I or H beams to span a 44 foot distance and each one needs to be capable of holding its own weight plus at least a couple of tons in the middle. Also we've got a 24.5 foot span that also needs to hold the same weight.

I just need to know how big of beams we need to acomplish this.

Is there any kind of online calculator on an engineering website or some guidelines to go by?

[MarkM]

The guidelines will vary depending on the buildings use, commercial has different regs to residential. I have someone to ask this exact question but be aware that US buildings codes will be different to mine. For example you guys use akros (sp?) to hold up your houses permenantly where as we use them as temporary supports only.

[RapidTransit]

Theres a couple of good books at www.wiley.com

[billybob_81067]

The guidelines will vary depending on the buildings use, commercial has different regs to residential. I have someone to ask this exact question but be aware that US buildings codes will be different to mine. For example you guys use akros (sp?) to hold up your houses permenantly where as we use them as temporary supports only.

Well this will probably not be built to code... this is just for my dad and I to build a chain hoist in our farm shop. We just want it plenty strong enough to lift a couple of tons for hoisting engines and other misc stuff. The two longer beams spanning the 44 foot distance will be stationary and the smaller beam spanning the 24.5 foot span will be on a trolley system so it can roll the length of the shop. Then we will have a chain hoist on a trolley system that rolls the length of the smaller beam so we can reach practically anywhere in the shop.

In the picture the red beams are the long ones, the blue beam is the smaller cross beam and the grey circles are the pipe coming out of the ground that will support the whole thing.

[MarkM]

Ok going from your drawing the specs for the steel you will be able to get from the steel supplier as they have to have the load rates etc for varied applications, This will include how deep you will have to set the poles in the ground and also what type of concrete you should use to set the posts in place. The weak point will be the trolley system as this is where the real load is so even if the cross beam is rated for the weights you want to use (as well as the side supporting beams) the trolley system will have to have bolts/wheels etc all rated for the same weights. Not saying it can't be done but the design will have to be looked at a little closer. Basically you are designing a warehouse crane lift. Block and tackle is available for the weights you want so that part is real simple.

[nippinout]

You're going to need more than just a website.

Load and Resistance Factor Design is the common practice, the American Institute of Steel Construction puts it out and is the standard for steel design guidelines.

It isn't just a matter of withstanding loads. You must design your structure in such a manner that the lowest strength is above your required strength. Such as your connections (welds, bolts, or combo), yielding, buckling of the web or flange, torsion, factored loads (wind, precipitation, earthquake...) blah blah blah.

Or just over-engineer it by picking some big *** I beams with some bracing. I'm sure some bored structural student will do this design for a meal and a beer.

Good luck, and be safe!

[billybob_81067]

Or just over-engineer it by picking some big *** I beams with some bracing.

That's the direction I was planning on going anyways!

I figured I'd find out what the smallest we would need would be and then go 2-4 inches larger in I beam size. For the rollers on the trolleys my grandpa's got a buttload of army surplus 4 inch roller bearings that will do the trick nicely.

Here's a pic of the trolley/roller system I've got planned, the purple is the bearings and there will be 2 per side of each beam for a total of eight plus another 4 on the chainfall trolley itself.

[IronCore]

your looking for something similar to this

http://www.gorbel.com/pdfs/Jib%20Brochure/Gantry.pdf

I think its better to roll the blue beam on top of the red beam IMO