Lifting capacity of existing bridge crane
Lifting capacity of existing bridge crane
(OP)
I've got a project where the client is asking me to come up with a lifting capacity of an existing bridge crane. I have the existing structural drawings and I know the runway beam and cap channel sizes and the crane rail, but for reasons I can't get into, I do not have any other information about the existing bridge crane and I will not be able to get any information. Is there a way I can determine an approximate bridge weight and hoist and trolley weight? I know I will probably have to get in touch with some manufacturers, but does anyone have any rules of thumbs or existing catalogs or something similar that might get me started? Since I don't have access to the site, the client has asked me to approximate (to the best of my ability) the missing weights.
The runway beams are simply supported, 40 ft spans, and are W21x44 with C15x33.9 with a 40# ASCE rail. The bridge span is 30 ft. Thanks in advance.
The runway beams are simply supported, 40 ft spans, and are W21x44 with C15x33.9 with a 40# ASCE rail. The bridge span is 30 ft. Thanks in advance.






RE: Lifting capacity of existing bridge crane
With what you have you might be able to generate a rating for the support system.
But the bridge and hoists are a critical part that you know nothing about.
Rails that will support 50t don't matter with a pair of 10t hoists.
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P.E. Metallurgy, Plymouth Tube
RE: Lifting capacity of existing bridge crane
RE: Lifting capacity of existing bridge crane
RE: Lifting capacity of existing bridge crane
You can run through the structure and see what the limit of everything is.....but (based on my experience) a lot of times they have a number in mind.......and having that in mind is good while evaluating everything.
RE: Lifting capacity of existing bridge crane
RE: Lifting capacity of existing bridge crane
RE: Lifting capacity of existing bridge crane
Will you be able to do a field visit at some point? You could theoretically tell them that you'll rate the steel based on available information, but if that comes out okay you'll have to come out and figure out what other information is available for the equipment.
The other option, I guess, is to load rate the steel and then load test by incrementally adding weight until the equipment breaks or you prove that it can lift what you want plus an appropriate factor?
RE: Lifting capacity of existing bridge crane
Has anyone bothered to look up at the crane itself?
Mike Halloran
Pembroke Pines, FL, USA
RE: Lifting capacity of existing bridge crane
RE: Lifting capacity of existing bridge crane
need know:
Grade of steel beam and Cap channel steel
Proposed vertical wheel loads
Proposed Lateral loads
Wheel spacing
I can tell you that this section will not take much load @ 40' bay spans, the W21 has a narrow flange and fails quickly for sidesways web buckling AND tension
the tension limit is why you will need to know grade of steel - but one can assume anything built before 2000 has a good chance of being A-36. Channels were still often Gr 36 up to around 2010
AISC has a downloadable program that runs the beams for you
It works fairly well
Regarding Cr capacity, simply identifying the manufacturer & model # of the hoist would be a really good start
I assume is a package hoist so, there is likely a label on it somewhere
Regards
RE: Lifting capacity of existing bridge crane
RE: Lifting capacity of existing bridge crane
Look for a DeMag, Herrington, Kone or Gorbel crane catalog for more moderate lifts.
As noted above the 40' bay length is going to have a very low capacity. Normal bay lengths are 20', 25' & up to 30' bay lengths.
Jim
RE: Lifting capacity of existing bridge crane
http://www.cisc-icca.ca/files/publications/techpub...
It's targeted to the Canadian steel code, CSA S16, but it's pretty code portable, I think, and contains useful general information.