Choose of gantry crane

[gdf_77]

Ok Guys and Gals. I am looking for some help. I am thinking ahead, 8-10 months, I hope to be putting up a little shop, and my discussion topic is Gantry Cranes. I have seen people with both rolling and full shop length. I have also seen jib cranes. What I am looking for is a little insight from y'all so I can decide which way the floor should be poured. Either with some thicker concrete for the posts or not. i will be doing some of everything, some auto body, heavy steel fab, light steal fab. So I would like to hear personal experiences. Thank You.
Gabe

[DSW]

Thick to thin spots in a continuous pour is asking for cracks. Any time the thickness changes the concrete will have a tendency to crack. You can avoid this several ways. One keep the floor a continuous thickness and have separate footings under where you want the column supports. This will reduce but not eliminate the chance of cracking because the sub base may not give the same support the footing does. 2nd Pour the spots for the posts separate from the floor ("diamonds") and put cuts or control joints between the spots to control where cracks occur. 3rd Pour the floor thick over the whole area. This works best for light to moderate loads where footings are not required. We'd frequently do this for things like where shop lifts might be installed later.

We usually poured 3500psi crete and added fiber for all our pours. For drives and shop floors we usually poured 6" slabs, 8" in some that we knew would get heavy use. Often we would use 4g wire mat on 2" chairs and #4 bar if the sub soil was soft (river silt) on at least 6-10 inches of crushed stone. On harder sub soil we'd beat the snot out of it with the roller and use 4-6" of stone, wire and bar being optional. All slabs were saw cut usually into areas approx 10' x 10' to control cracking.

For shops we also frequently laid radiant tube in the floor for heat. If so we laid the mats and chairs to tie the tube to. It's relatively cheap and easy to do and gives you a nice warm floor to work on in cold weather. You can heat it simply with a standard hot water heater, some RV antifreeze and a circulating pump.


As far as which to get.. The travel crane would be the nicest, but most expensive. My buddy's got one in his shop and it's sweet. We made do with a small A hoist that we could roll around at my old place, but it was a real pain to move with a load on the uneven floors. I've also made use of a jib crane at another friends shop, but it's only good in one area. Works well if you have heavy loads that are usually always in the same area.

[gdf_77]

Thanks DSW. I didn't mean that the floor itself would be thicker. i typed this up after an 18 hr day. I had meant to use the term footings.
As I said this is the initial planning stage. Alot easier to plan for the future, than remake the past.
Thanks for the input.

[knucklepanshovel]

concerning the floor, not sure how much body work are you planning to do? but floor pots to hook either a pulling post to or a pull dozer, etc, can make pulling out major damage alot easier. more suited to backyard shops than a full frame machine.

Later,
Randy

[Static-XJ]

Originally Posted by gdf_77

Ok Guys and Gals. I am looking for some help. I am thinking ahead, 8-10 months, I hope to be putting up a little shop, and my discussion topic is Gantry Cranes. I have seen people with both rolling and full shop length. I have also seen jib cranes. What I am looking for is a little insight from y'all so I can decide which way the floor should be poured. Either with some thicker concrete for the posts or not. i will be doing some of everything, some auto body, heavy steel fab, light steal fab. So I would like to hear personal experiences. Thank You.
Gabe

Gantry cranes have their own wheels and can be used anywhere that you have a level surface. If you need to roll it outside the shop, no big deal. But you need clearance on either side of a load for maneuvering the gantry legs. An example is loading/unloading a pickup or trailer. The only way on or off is from the rear of the vehicle, you can't just pick something up and go over the side (of course this assumes the crane isn't much wider than a trailer).

Bridge cranes are fixed in place. The hoist(s) is mounted to a trolley, which is mounted to a bridge (the main beam of the crane), which rides on a runway (the two beams on either side). The area these cranes can cover is fixed, but you have more versatility over what you can do with it since there is no extra clearance requirement like a gantry has. If you are planning on getting a steel building, you might inquire with the manufacturer about prepping it for a bridge crane. It can either be designed for an underslung bridge, where the runway is suspended from the roof joists and the bridge trucks ride along the lower flange of the runway beam. Or the columns can have the mounts for the runway of a top-running bridge incorporated into the design. Either option eliminates the need for the crane to have it's own columns, so the crane takes up zero floor space. But on the other hand, a crane system with it's own columns separate from the building gives the option of disassembling the crane and taking it with you to a new shop in the future.

A jib crane is mounted to a a pivot. The trolley can reach anywhere under the jib. 360° motion is possible using a floor mount post, but this now means you have a post somewhere in the middle of your floor. Jibs can be hung from building columns (if they are designed with this use in mind), in this fashion you get 180° of jib swing, with zero loss of floor space. You won't be able to go from one end of the shop to another with a jib crane.

Your desired capacity may have a large bearing on what type of crane you choose. Below about 1 ton WLL and under 16' height I prefer non-motorized trolleys and trucks. Heavier than 1 ton or above 16' height you're going to want powered movements. Non-motorized trolleys and trucks are nice in that they will center themselves over the COG of the load, so long as the hoisting is done slowly. With powered trolleys and trucks you have to make these adjustments as you are hoisting.

[jpump5]

I have a 5 ton gantry crane at my job.Rolling it around is a huge PITA.
Co-workers have jib cranes.Much easier to use.

[jpump5]

Also- I've been told that jib cranes were
installed after the building was finished.
Floor had to be cut out and large footings
poured.

[Mondo]

If I were building a new shop I'd like to have a rolling beam that spans the full width of the shop, or at least one full bay. A rolling beam permits picking and setting a load anywhere on the floor. I know two fellows who each have a rolling beam in their shops. One is a single bay, 16 x 32, the other is two bays, 32 x 36. The 16' beam rolls at the tug of a tag line, the 32' beam has an electric motor. Both use an axel with a pinion engaging a rack on each end of the beam so both ends move in unison to prevent the beam from getting skewed on the wheel tracks. Both arrangements can be fully operated by a single person.

You will need to do some engineering to select a beam strong enough to properly support a point source load at least equal to the heaviest you intend to handle and you'll need to assure the beam tracks are adequately supported either from separate columns or by the building structure.

A free-rolling gantrys take up space when not in use and can be a PITA to move about, especially with a hanging load and often require two or more persons handle safely. But if not taller than the doorway or are adjustable in height they can be rolled outdoors and have no limits on positioning. Nor do they require any additional engineering of the building.

Jib cranes are limited by the length of the beam and the swing radius, though a rolling trolly hoist is handy. A single post support requires a relatively large, perhaps even massive counterweight in the ground to keep it from tipping or leaning in time. A jib secured to the wall or side frame of the building will need to be engineered or limited in capacity to assure the structure can support the side stresses that will be applied when lifing a load at maximum radius. The benefit of a jib is it is simple and can often be mounted near the edge of a door such that it can reach outside.

My choice, if I had the opportunity at this time, would be a rolling beam. A bit more complicated to install but the versatility is as wide and as long as the floor area over which it rolls. And it consumes no space to speak of when not in use. You hardly even know it is there.

- Mondo

[7A749]

As was mentioned, it all depends on what you want to do, what you can afford & how much skill you have to fabricate it.

Sure, rolling bridge cranes are real nice, but you better hold on to your pocketbook. Even purchasing used equipment & retrofitting it will cost some dough. Gantrys are sweet if you have a BIG shop with lots of room, a smooth floor to roll it on & a place to keep it out of your way when you don't need it. No so in my case so I went with the simple solution.

I built a simple single beam rolling trolley in my carport. I got most of the I beam cheap as scrap & had to buy the main span new. This was nearly 7 years ago when steel was quite cheap. Not the case now.

I have 4" thick concrete & just installed two 1" drop in anchors in each base plate with epoxy. If I had to do it over & had money to burn, I would have cut the floor out in the leg sections & poured deeper footings or mounted the posts in the concrete. The carport was already there, so I had to work with the existing height restrictions I had. The top beam is held in place with simple toe clamps. Made it a LOT easier to position & secure it. Entire superstructures were constructed & hung from vertical beams & ceilings in the GM plants I worked in with the exact same concept.

It's limited to being stationary, but I have used the crap out of it since I built it. I have lifted about 1500# with ease. The legs need some additional bracing, but I don't feel at this point I'll gain much unless I totally go nuts on it & for what I use it for, not gonna happen.

Look at cost versus application & go from there. Biggest deciding factor as far as I'm concerned.

IMHO or course.

[7A749]

Oh, I will add this....

If you want a versatile tool for lifting & transporting heavy items, look at a good used forklift.

For what you'll spend on the simplest bridge crane, you could easily purchase a decent solid tire lift. Three grand will buy something reliable for sure. Lots of machines out there, just look around when you get ready to start.

Besides, you'll most likely need one to put up a bridge crane anyways.....

[gdf_77]

Thanks for all of the replies. I will be moving my current garage 22x24 roughly, and using that for my shop. A new 30x30 with 2nd floor will replace it, sounds easy right?
Anyway, thanks again for the input, I think since it is going to be a small shop, that I will probably go with a rolling bridge. I just don't think I will have the room for a gantry.
But all in all I still need to clear it with the Financial Officer of the House.