Crazy idea...

[IGOR]

So I want to put up a carport on the side of my house next to my garage -

One of my buddies suggested jokingly over a beer to use a free-standing overhead bridge crane.

At first I laughed him off - but the more I think about it, the better it sounds...

I was thinking of installing standard engineered wooden trusses on top of it and simply bolting them down to the metal I-beam on the top of the crane.

I could get any span I want, it's modular, and I could get it tall enough to drive a RV or big 5th wheel under...

Couple of questions though

- would this be stupidly expensive?

- how much do trusses weigh - is this going to hurt the crane - or would I just have to reinforce it?

Thoughts, opinions, concerns?

 

[OldCarGuy]

The first thing that comes to my mind in building a building around a pre-designed bridge crane is that it was designed to carry its’ own weight plus the capacity of the crane. And not any structures built on top of it. It would take a Structural Engineer’s input to determine how to strengthen the crane’s members to accommodate the roof. And if you need a permit in your area, they will have to approve the plans. And most likely want a Certified Engineered stamp on the drawings.

It’s always nice to think outside the box and is a cleaver idea to explore.

 

[joecaver]

I question the need to bolt the trusses to the crane. A truss is built to cross a span with no support except from the outside walls. The free standing crane is built to support itself with no help from the truss. Why would you want to tie those together?

 

[IGOR]

To put a roof over it - I'm in OR and it rains a lot!

- the roof would be built right on top of the crane structure. The 4 legs (or however many) would be my wall supports, and transmit the end loads of the truss to the ground.

I'm an Engineer by degree - don't have my professional stamp - but it doesn't seem like it would be to hard to design something up...

 

[Kruse]

Might work...
The structure is already designed to take some side-forces from swinging loads.
The forces off high winds or a storm may be a different story.
By adding side legs for support of the roof and walls and cross-strengthening the corners, it would probably be safe.
I do not think the weight of the roof structure, if constructed light, will be a problem.

 

[MXtras]

I can't imagine that a bridge crane would be cheaper than a steel building of equivilent size.

Scott

 

[mleichtle]

I question the need to bolt the trusses to the crane. A truss is built to cross a span with no support except from the outside walls. The free standing crane is built to support itself with no help from the truss. Why would you want to tie those together?

Being open on all 4 sides, the roof would be subject to quite a bit of uplift.

My thinking is, the crane might already be designed to have a roof structure on it as a safty factor, the thing is huge, and I could see some using one outside. Does the manufacturer say it has to be installed inside a building, or can't have a roof structure on it? Those end I beams look rather large for supporting absolutly nothing.

 

[tubeman]

It shoould make a great garage and the crane would be all set. The cranes are not cheap though. One without any lifting hardware is over $3500. That is for a 12x10x10. You could build the frame for much less than that but if you want to buy a crane anyway it makes sense!

 

[FEF]

HAving just gone through a garage design, I know they will ask for the engineering stamp that proves the structure will hold it.

It might fall under the heading of a "poll building", but they are "engineered". This is not "engineered" to hold trusses, sheathing, and roofing shingles.

I don't think it's a bad idea at all, but it will take a few "pages" of "engineering", before you'll get a building permit.

It's all about money, really.

 

[OldCarGuy]

It shoould make a great garage and the crane would be all set. The cranes are not cheap though. One without any lifting hardware is over $3500. That is for a 12x10x10. You could build the frame for much less than that but if you want to buy a crane anyway it makes sense!

I had a friend in the crane business recommend beam sizing. And total cost for my 27’ main beam with the 45’ runways and 12’ high 4,000 pound capacity bridge cane was a bit shy of $2,000.00. I purchased about 4,200 pounds of I-beams and H-beams that cost me about $1700.00. Yep,, roll stamped into the webs is Made in the USA. That’s about $.40 per pound. Because I don’t like to discard anything I had the steel & wheels for the end trucks, column mounting plates, two-ton trolley, two-ton three-phase electric chain fall, nuts, bolts, and paint. I spent another $200.00 for the homemade festoon electrification cables, pulleys, and cables.

 

[tubeman]

How long ago was that? They don't sell steel for $.40/lb around here anymore!

 

[OldCarGuy]

It was ordered December 2005 and delivered January 2006

 

[IGOR]

Yeah - so I've been getting quotes on bridge cranes - they range $9-$12,000...

Might have to build my own carport under permit, with steel sides & top I-beams, then add the crane later -