Stationary Gantry Crane: I-Beam Help Needed

Hey, it sounds fun.
Sorry it's not my field of expertise...but I'm sure one of the guys here will advise.
I'd go for the 'bang on plus a bit over' principal myself , or the 'what I can lay my hands on'.

Sometimes, one reply draws in a few other suckers replies.

Good luck
Del

This goes against my better judgement to give details about structural design - but it seems you have put some effort into thinking/working on this and have a good plan.

For your situation I would use either a W6x12 or W8x10 (or heavier) to span 16' and be safe for lifting 1000 lbs (note I have also included a safety factor, but you don't necessarily need the details on that - just know that those beams are more than adequate for 1000 lbs including any sensible dynamic effects)

Just one question - these 8x8 posts you refer to - do you mean solid wood posts 8x8"? Or 8" steel I-beams, or 8" rectangular hollow steel?

I am almost afraid to answer this, but I will be using wood post uprights. I realize that it's not the best solution, but it is the most structurally sound solution for the money. I will just have to be dilligent about their upkeep (inspection, stain/paint, etc.).

Now't wrong wi' wood lad.
It were good enough for Henry VIII's ships and longbows...

First thought is the uprights should be alright -

However, if you give some details (and a little time) I can confirm that -

1. Are these solid posts? Or built up from 2x8's? Or ............?
2. What type of wood? What grade?
3. How are you going to connect the I-beam to the posts?

Hello guest,

If you are governed by OSHA or similar administration, you will be required to provide evidence that your crane is adequate for its intended purpose. Structural advice obtained from a forum such as CR4 will not likely be deemed adequate to ensure worker safety.

Solid pressure treated 8x8 posts rated for ground contact

OSHA shouldn't be a problem as it's not at a place of business

I will attach the I-beam to the posts by "capping" the end of the it (welding 1/4" plate to the end) and extending down the upright by at least 8", and use either lag bolts or thru bolts to connect it to the wooden post. I'm also considering welding a section of angle iron to the I-beam at innermost intersection (thus creating a "U" cap over the upright) and possibly tie in with the thru bolts if I go with that option.

Thanks for all your help!

Excellent choice/thought on the "caps" I was going to suggest the exact same thing in my next response.

I will work out the posts though (like I said my gut feeling is you are fine).

(I had a suspicion someone would "object" to giving detailed design - No offence Ba/ael, like I mentioned it goes against my better judgement, but .............)

One addition you might consider making to stiffen the beam is to add diaphragms to the sides in the gaps between the top and bottom of the beam. I'd start from the free end and place them 4' apart. Use the same kind of plate you plan on using for the cap.

I suggest this because I have done drafting work for a company that makes bridge cranes, and have seen these used in a couple of applications.

Yes, that is a fairly good suggestion - those stiffeners are for twisting of the beam which would occur on an angled lift - they don't really do anything for bending.

Hi 3Doug,

We don't know what the hoist looks like. If it looks like the picture to the right, the stiffener plates will prevent the hoist from rolling freely along the bottom flange. I don't know if that is an important consideration or not. The OP will have to advise on that.

In any case, I am not convinced that stiffener plates at four foot centers achieve anything useful so far as strength is concerned.

If loads are likely to be picked up at an angle, it would be prudent to select a larger beam, say S6x17.25 or S8x18.4, both being a bit overdesigned, but much stiffer and capable of handling unpredictable situations.

Well, just to give everyone a "feel" for me, I value my life just as much as any other guy (or gal) out there. I don't want to build something that will be dangerous, or even worse, get me killed. I have too much to live for these days! I framed homes on the coast of Myrtle Beach, SC for 5 years so I do have an understanding of structural design, however subpar it may be comparitively. I have been into automotive mechanics for most of my life and I'm a graduate of automotive collision repair from my local college. I currently work as a CNC machine tool setter for a job that actually pays the bills while providing affordable healthcare insurance for myself as well as my family. So my experience range is pretty wide. I've always taken pride in the fact that I could be taught anything, but my greatest downfall is actually taking the time to become *educated* in any one field (with the exception of autobody paint & repair, but I was much younger & had all the time in the world back then).

Again, thank you all for your suggestions and comments! They are GREATLY appreciated!

I don't think anyone was being judgemental of you, your personality, or your character - the issue of offering detailed designs over an internet forum is a contentious issue - particularly in structural design. This is of course due to liability (a.k.a. "The Law") and the risk of harming people. If any information obtained from an internet forum is implemented and was ......................... I am starting to babble here.

To the point:

Your uprights are perfectly fine for this situation - you needn't worry about their strength at all.

Oh no, I wasn't taking offense. Just the opposite. I just wanted to make it clear that I wasn't Backyard Billy-Bob trying to cobble something together

I do understand the liabilties involved with giving suggestions and advice these days. The litigious nature of the general public has all but nixed that practice these days.

Oh, I forgot to mention that I will be using a trolley with the chain hoist so that I can center it all directly over the load as opposed to lifting from the side and putting undue stresses on the uprights.

Fair enough -

Like Bruce mentioned above you may go with an S6x17.25 or S8x18.4 rather than the W-shapes to fit any trolley you have (you could even go with a lighter S6x12.5).

You talking to me?

Welcome to CR4, home of the insanity clause. In Del's case that is claws.

Not less than 6"x10" Alum beam is 6"x8" spec'd for 16' span but you'll have something catch while removing. If I were going to spend time under it'd be an absolute minimum of 6"x12" Aluminium or 6"x10" steel.

Hi....niether the span nor the weights involved are high. You just got to use a MB 200 made of IS 2062 grade B. These come with tapered flanges (ref Bureau of Indian Standards). Tack weld a strip on both bottom flanges of size 35mm X Length of gantry beam which is less than 5mtrs. This will serve as the wearing plate & increase life of the girder. Before use test the whole contraption with 150% overload.

Good morning Guest. Without doing any calculations, it is noted the L.K.Goodwin Co. uses for their A Series, Fixed Height, Steel Gantry Crane, 1 ton capacity, Clear Span 18'-11": 10" I-Beam depth (S10x25.4, 25.4#/lf, flange width 4.661").

I have to say - I have done the calculations and the S10x25.4 is definitely overkill - you would be fine with an S6x12.5. (Trust me - I am not your average anonymous Guest )

Okay, can someone please explain the nomenclature (EI:S6x12.5=6" width x 12.5" height? What does the "S" mean)? Can you tell I'm green?

My plan was to use a standard "I" type solid steel beam for the span, and I don't think that I could afford to buy an aluminum beam. I had never considered the "W" types but I will keep it in mind. I would like very much to keep this as compact in height as possible, otherwise I would build it to a 10' height just in case I ever needed the extra room. I was actually thinking of using either a 6x6 or 8x8 "I" type beam for this. In your honest *opinion* is that too small? (I say *opinion* because I won't hold anyone to it, I'm just looking for general guidelines)

Also, I will admit that I haven't went down to the steel supply house yet and actually laid my hands on any beams yet, so am I correct to assume that there are different material thicknesses available for each size, or is there a standard thickness for a given beam size?

And by the way, I did register yesterday, but I still have yet to receive a confirmation email

Lastly - just so you feel more comfortable - both those shapes (Steel W6x12 & S6x12.5) have a factor of safety OVER 5 based on Yield strength.

Common practice is a factor of safety of 5 based on TENSILE strength (which is higher even yet than yield.

Please see:

http://www.michigan.gov/documents/CIS_WSH_part20_35459_7.pdf

Although I have no particular objection to your choice of a W6x12 or S6x12.5, I strenuously object to your further comments.

The safety factor based on Yield strength has no bearing on the problem as the beam will fail before it reaches yield. This is due to an unsupported length of sixteen feet.

It is not common practice (where I come from) to base the safety factor on Tensile strength for the same reason as just stated. The beam will fail long before it reaches its tensile strength.

The grade of steel has not been mentioned so far as I know (correct me if I'm wrong). Thus we do not know the yield strength or the tensile strength of the material. What Code are we designing to and what is the impact factor for the live load? What is the weight of hoist?

Notwithstanding all of the above, I believe that a W6x12 or S6x12.5 of A36 steel will safely sustain the load. If the load is 1000 pounds, the beam will deflect about 1/4" or about L/800...not too bad.

Hello ba/ael:

The grade of steel has not been mentioned so far as I know...........

This is the mention of the 'grade' of steel I think Bruce.

You just got to use a MB 200 made of IS 2062 grade B.

Take care............

Hello ba/ael:

forgive me, I forgot to say that 'Grade' of steel was talked about in post #20.

Sorry, I should have put that detail in the previous post.

Take care...................

I never should have gotten involved in the first place .......................

(This goes against my better judgement to give details about structural design)

To "save face" I will respond to Ba/ael's perfectly legitimate comments -

1. Please check my calculations based on the minimum yield strength material you could ever hope to find in North America (without getting into ridiculous scenarios).
2. I made some perfectly reasonable assumptions about other loadings.
3. I presented the "short-cut" route of safety factors to keep things within the technical knowledge of the original poster.
4. Code of Federal Regulation, Title 29, Part 1910.179, "Overhead and Gantry Cranes"
5. Crane Manufacturers Association of America (CMAA) Specification No. 74 "Specifications for Top Running & Under Running Single Girder Electric Traveling
   Cranes Utilizing Under Running Trolley Hoist"
6. American Institute of Steel Construction (AISC), Manual of Steel Construction, Allowable Stress Design, 9th Edition
7. American Institute of Steel Construction (AISC), Manual of Steel Construction, Load and Resistance Factor Design, 3rd Edition
   
8. I made a wrong assumption (had another scenario in my mind) about the use of stiffeners and twisting in an earlier post.
9. I do not have multiple personalities as suggested by others, and I am not the original poster answering my own questions.

................. I never should have gotten involved in the first place ....................... I knew better ............................ (sigh)

Hey, don't worry about it! We all do it occasionally. I never believed that you were a multiple personality and I am quite sure you were not the original poster.

Hello ba/ael:

or is it guest?............................Sheeeesh, now I am really confused, like......talking on 6 phones at the same time. You are either very clever, or I am dumb.............I think I know the answer; I think I am dumb! But, I do not 'know' I am dumb, so, as a concept it doen't enter my way of thinking at all. I just get more confused with each post..................I think?

Hello babybear and bob c,

Bob, you can be #27 if you wish. That number will be reserved just for you and nobody else can use it. No. 27, five by five plus two, three by three by three or 3³, one cubic yard or 27 cubic feet, the atomic number of cobalt, #27, bob c's number...don't anybody else even think about using it.

And babybear, what's to confuse? Everything is crystal clear. Whether I sign on as ba/ael or guest, I still look the same...look below, I'm just doing my daily exercises.

ba/ael or bruce (take your pick)...good night for now.

Hello Guest (later to be member),

If you are going to build it, you need to think of those times when you just might try to give a friend a hand or, he asks you to help to lift something from the back of a truck.

Do you risk it, or do you know for sure it will lift say 4 times the weight of anything you would be likely to fit under it anyway?

Also make sure any chain is equal to be used with the I beam. And, the same goes for the wheeled dolly.

Good luck!

How about some pics when it is done?

Is it just me, or do you get the impression that Guest is asking questions that are hard, just so that he can answer himself as Guest? And is Guest really have multi-personalities, and is contradicting his own answers?

Hello 'guest',

when there is so many guests on this thread it is hard to see whom is the real guest, and whom is just here for the bear?

The original thread was started by someone who said he had tried to join but, the confirmation email had not come through. My confirmation email was almost instant.

Perhaps he should go through the 'joining' process again? And you, me? No him. No over there. There is so many guests I am not sure to whom I should talk?

Try joining guest, its a great place!

Although I am currently posting anonymously, I am, in reality ba/ael. This thread is getting a bit hard to follow, so why don't the guests respond as Guest #1, #2, #3, Hal, Jarvis, Batman, Superman or whatever other name you want to use.

Signing off,

ba/ael (otherwise known as the little birdie)

Me first I want to be Guest #27. My lucky number.

Just curious...a Gantry crane is by definition a mobile crane is it not? A "gantry" crane that is permanently immobile is, I believe, a bridge crane. I think that's one of the differences between a bridge crane and a gantry crane.

A gantry crane has wheels on its support pillars so the whole device moves.

"Bridge crane" is another name for an overhead crane. They are called bridge cranes because they bridge a work area such as a factory floor. The crane itself moves along an elevated rail system that is fixed in place.

A jib crane is fixed at one end, but could be mounted on a pivot to allow it to move in an arc. I got the impression from the original post that this is what he planned to build. Jib cranes often have the hoist fixed onto or near the free end, and that is why I suggested the diaphragms.

It sounds like he plans on having both ends supported by fixed pillars. This would make it a fixed overhead crane, or a monorail.

Yes, you are correct. It will be supported on both ends, so a "fixed overhead crane" is what I should call it from now on

Okay, OP "Guest #1" here-LOL!

It certainly appears as though I have quite a bit of homework to do concerning the grades of steel, shapes and whatnot. I was thinking that this would be a very simple selection process, and now I can see why no one local would offer any suggestions-there are too many variables in materials, to say the least. When I mentioned earlier "6x6 or 8x8" I was referring to a beam's width x height. I was unaware of how they were actually measured. You guys have certainly opened my eyes a bit.

The reason I called it a "gantry crane" was simply because that's what I felt it most closely resembled, and I didn't know what else it would be called.

Hello 'guest #1'?

Just to say, it is good to have your eyes open. Especially when building and using this crane of yours!

Take care, and I still don't know to whom I am speaking!

"Guest #1" here....

I just tried to register again but I still get nothing in my email.....

I even tried to register a third time using an alternate email address I use for business and still no luck.

For the time being, why don't you just sign your posts with your screen-name-to-be?

That would make it a lot easier for us to follow the "guest's list"...

Hey guys, just wonderin' - is there enough room for another guest in here?

Guest #1, Be very careful, someone is trying to pass himself off as you under the screen name of Mike the Jeep Guy. This could be some plan to steal you crane plans before you can get them patented. Be very careful.

Guest # 27

Okay, here I am, the original poster. The email finally came through in my business email!

Welcome MiketheJeepGuy! I'm a Jeep guy too.

Thanks for the welcome! My side business is used parts for Jeeps, mainly Cherokees & Grand Cherokees, and this is why I need this crane. It will help greatly in the removal of engine/transmission/transfer case combos, or the occasional CJ/Wrangler body tub so I can avoid doing it in the driveway when I finally get it built.

Ah, I got a '02 Wrangler Sahara, stock. My son's got a '94 YJ. I'm in the market for a CJ-5, with a V8, restored, turn-key.

Hey! I have a Jeep too! and I own and operate a steel fab shop!

Ain't that somthing?

Dave in New Orleans...

Hey Dave you need to register on CR4 your input would be appreciated

Now that you have moved in to this CR4 place, I have a problem that I hope you can help with. I have a friend's 1998 Grand Cherokee with the 4.0. It has been dying on him after a period of 15-30 min. driving. He replaced the fuel pump to no avail. It had a code stored for an air charge temp sensor. I changed that. Still no fix. I now have the car, and there is now no power to the ignition coil. It obviously will no longer start at all now.

Can you tell me where the coil is getting power from on this? Is it directly from the ignition switch, or is there other crap components in the system between?

How is the crane coming

www.alldatadiy.com

Hello bob c:

The problem you have sounds very similar to one I had, but not in a Jeep.

The problem on mine was two-fold. Firstly, the battery was not tied down and on a corner it sometimes earthed out. I could not figure where all the burning smell was coming! The other thing which was wrong at the same time was I tiny hole in the Carburetter diaphragm. It always failed or cut-out with the extra demand for fuel. I did not realise it had a vacuum in the carburetter and, took it apart about six times before I stretched the rubber on the diaphragm and could see through it!

I have no idea about the fuel system on a Jeep, and if it is Injected, I apologise for wasting your time, OK.

Good luck and take care.......................

Thanks for your thoughts. This is FI. As for the battery, I once tried to use a battery that was too tall for the application. Shop rags are not sufficient insulators in that application. Burnt the paint off the hood.

I am just involved in another project, and can't get to the shop where the manuals are.

Hello bob c:

You know what I mean about the battery then. Mine was in a pickup and the battery was on a shelf behind the drivers seat, and it was earthing/shorting out on the steel of the seat!

Take care bob c

The first thing I would suspect is the crank position sensor, or possibly the sensor's plug on the wiring harness. I had one that had similar symptoms as you describe. When the CPS doesn't give a signal to the computer, the computer can't relay the signal to the coil to fire. I would try to find a used, but "known to be good" CPS and swap it in (it's located on the driver's side of the transmission bellhousing). If that doesn't fix the problem, the plug may be bad. I had to cut my plug out of the harness and use butt connectors to put it back together, but it ran like a champ after that.

Thank you for your reply. The only code at this time is O2. Would the CPS set a code? And would both sides of the coil be dead? Can I remove the CPS and trigger it with a steel object, and watch for coil firing action? Thank you again.

If the O2 sensor is bad it will still run, it will just throw a code. So I think we could possibly rule that one out. Also, I don't see the two being related, but I've been wrong before I know it sounds elementary, but have you checked the fuses, both inside and under the hood? Sometimes a fuse may be good, but simply have a bad connection. Also check for any bad relays in the underhood panel. As to checking the CPS, I've never done it, but I don't see why you couldn't give it a try.

You won't have a ground to the coil in static mode, but you should have 12v + power when the ignition is on. Seeing as how that is the case I would first start the deduction process of trying to find out why you have no 12v +, then go from there. You could always try to hook a 12v + source directly from the battery to the positive side of the coil and see if the engine fires. You won't burn up the coil because the computer & distributer pickup send the ground signal.

That was my opinion of the O2 sensor also. I will check the fuses inside next. I already checked the under-hood ones. If time permits, I will hit it again Sunday. Thanks again for your help.

The hall effect sensor in the distributor and the ignition control module, in that order.