help figuring steel needed for hoist/roof support

[RedNeckRacin]

Cat_Driver nailed it. There are those of us who have had structural steel classes and those who have not. I do not have my license though. Much of that design knowledge is rusty in my head but I still have the books and would not hesitate to build something myself or criticize someone else's work/numbers. Any critical structure or device which has the potential to hurt someone should be reviewed by a professional who has experience with steel design.

Everyone likes to throw up a beam table from the internet and say that will work. What the uneducated/uninformed don't realize is that there is more than one failure mode that must be accounted for when designing with steel. IIRC there is around 7 of them? (Someone can correct me on this if need be but its more than 1 or 2) The simplest solution to these failures is to over estimate/oversize everything and a lot of the problems go away as long as weight/cost isn't a concern. While a single beam this might be a solution but its cost prohibitive on a larger scale and why structures must be designed by professionals and certified as such. [/rant]

 

[newbury]

With travel time to and from my site I doubt I could get an engineer w/ credentials to design something for less than $500 to $1,000 they don't work for free.
A quick check online shows I can buy a mobile gantry crane with the approximate dimensions I need for about $1,400 http://www.hoistsdirect.com/shop/1992#tab1 w/o shipping.
I'm not building a complex structure.

It's getting so every thread on here recommends hiring a professional for anything.

 

[Shield Arc]

newbury that chart I posted above. I found that on a gantry crane web site. So those are point loads in the center of the span. They are not allowable uniform loads. Generally points loads are about half of uniform loads.

Here is a chart for W shapes, they are stronger than S shapes. They do sell trolleys that will run on the flange of a W shape.

 

[CNC Dan]

......
What sizes/thicknesses would be needed for either tube or I beam? Or is there a site with a handy calculator to help me work it out?

I don't know. I just had to point out that using angle as a post is a bad idea. If you took the same amount of steel, and made it into a tube, it would withstand higher loads. But how much load? Or what wall thickness/diameter would be best? I haven't a clue.

That's what engineers are for.
I am not an engineer.

 

[KennyG]

I am a registered Professional Engineer and I'm not going to get into trying to design this thing because I'm not sure I fully understand the configuration. However, let's not get carried away. 2000 lbs (1000 lbs per post) is not much. My 4x6 pole barn posts carry about 6 times that under snow load and I'm sure they have all kinds of margin.

The post above that angles make bad posts is correct. Angles are good for members in structures but posts should be closed forms (tubes or pipes) to give equal buckling resistance in all directions. If I was doing this and was sure I wasn't going to exceed 2000 lbs, I would seriously consider wooden posts. In any event, make sure you have appropriate bracing to keep it from buckling or folding. (And don't stand underneath when lifting.)

 

[CurlyDave]

With travel time to and from my site I doubt I could get an engineer w/ credentials to design something for less than $500 to $1,000 they don't work for free.
A quick check online shows I can buy a mobile gantry crane with the approximate dimensions I need for about $1,400 Vestil FHS-4-15, 2 Ton, Fixed height Gantry Crane, Height 10', Span 15' | HOISTS DIRECT w/o shipping.
I'm not building a complex structure.

I would buy the crane in a heartbeat and be done with it. A gantry on wheels has so many advantages over a fixed crane it is hard to count them. But the big deal is the crane can move to the truck so a lot of possibilities open up. Plus, the maker of the crane has done the engineering and is responsible for it.

If I were doing it, I would spend a little more and get a 4,000 lb crane, or maybe even higher. Match the crane to the cargo capacity of the truck. If you want to lower the span, this reduces costs and makes it easier to rate the crane for a higher load. I don't know what you are planning to move, but anything that is 15' wide and only 2000 lb is a very strange load.

 

[newbury]

With travel time to and from my site I doubt I could get an engineer w/ credentials to design something for less than $500 to $1,000 they don't work for free.
A quick check online shows I can buy a mobile gantry crane with the approximate dimensions I need for about $1,400 Vestil FHS-4-15, 2 Ton, Fixed height Gantry Crane, Height 10', Span 15' | HOISTS DIRECT w/o shipping.
I'm not building a complex structure.

I would buy the crane in a heartbeat and be done with it. A gantry on wheels has so many advantages over a fixed crane it is hard to count them. But the big deal is the crane can move to the truck so a lot of possibilities open up. Plus, the maker of the crane has done the engineering and is responsible for it.

If I were doing it, I would spend a little more and get a 4,000 lb crane, or maybe even higher. Match the crane to the cargo capacity of the truck. If you want to lower the span, this reduces costs and makes it easier to rate the crane for a higher load. I don't know what you are planning to move, but anything that is 15' wide and only 2000 lb is a very strange load.

I wrote I needed to lift 2,000 lbs max and the 13.5 foot width I'm trying to deal with is present post spacing. This would let me span my trailer and lift something off to the side.

And the link I posted was for 2 ton rated crane, should I look instead for a 4,000 lb rated crane.

 

[CurlyDave]

I wrote I needed to lift 2,000 lbs max and the 13.5 foot width I'm trying to deal with is present post spacing. This would let me span my trailer and lift something off to the side.

And the link I posted was for 2 ton rated crane, should I look instead for a 4,000 lb rated crane.

2 Tons = 4000 lb.

When taking a load off a vehicle, the typical method is to lift it and drive the vehicle out from under the load.