Underhung Monorail crane 1

[hawkaz]

I am getting no help from the trolley manufacturer- so I would appreciate input here

I am designing a simple monorail beam for a 2 ton underhung crane. The beam will be over 100 feet long, so it will need a splice. The manufacturer indicates that the beam width must be between 3.5" and 5.5" wide. Since we have a splice, I am thinking that I need to add the width of the splice plates and bolt heads to the 3.5" minimum requirement. I am looking at 1/4" plates on both sides of the web, with 5/8" dia. bolts- overall width = 1.5". Does it make sense that my beam needs to be 3.5" min + 1.5" splice = 5" min width?

The other option is to use welded splices- but I believe that runs the risk of warping the steel and possibly cause operational issues with the trolley. Does that sound accurate?

Thanks in advance

 

[DaveAtkins]

The manufacturer is talking about flange width, so putting splice plates on the web will not increase that dimension.

And, yes, you should bolt splices--not weld. Fatigue is an issue with welding splices.

DaveAtkins

 

[hawkaz]

Our wheels are running on the bottom flange of the beam- would the extra width from the splice plates create an obstacle for the wheels?

 

[Brad805]

here is a very common trolley for this application. They do make versions that have the proper taper for an S beam, but they are not quite as common everywhere. Do not make it more complicated than you need too. Be sure to look at how one might physically get the beams into place. Long sections tend to be a problem for this reason.

http://www.jettools.com/us/en/p/2-hdt-2-ton-manual-trolley/262020

 

[CANPRO]

Whether or not the splice plates interfere depend on the geometry of the trolley and the beam/connection - in my experience this has not been an issue...you just need to draw it to scale and check.

I typically show the beam splice cut at 45 deg (in plan) so that the wheels don't fetch up on the gap in the bottom flange on both sides at the same time.

 

[hawkaz]

Thanks Everyone

 

[TehMightyEngineer]

The trolley manufacturer website or contact should be able to provide you with detailed scale drawings of the trolley and it's clearance requirements. Typically I've either made the trolley beam continuous with no issues or had a series of single simple spans with small gaps as CANPRO indicated (though this can be an issue with riding over even a small gap on a single wheel).

Professional and Structural Engineer (ME, NH)
American Concrete Industries

http://www.americanconcrete.com

 

[FLCraneBuilder]

You stated monorail would be 100' long... I guess we should assume its not clear spanning 100' please clarify if so.. changes everything I'm typing below.

Anyway - one option is to find a different trolley hoist.... - they can be ordered up to 12" flange width if a chain hoist & maybe 15" if wire rope.. note that I do not like to sue lighter capacity wire rope hoists.. two easy fro small dia rope to pull out of drum grooves.

I disagree with fatigue concerns ref welded splice .. assuming the splice is located in line with a support

we often weld the bottom flanges together because the flanges are often rolled differently due to mill tolerance for flange roll (tip),,,

I suggest you review how the patented track people resolve some of these challenges...
I've pasted a link to one of their brochures

http://tcamerican.com/files/Perfect Beast.pdf

BTW - what lateral force are you applying for beam design?

regards