Overhead Crane Reaction Loads

interesting.

so basically what are you looking for? could you describe exactly the type of activity?

what do you mean by wheel loads ? wheels of the crane ? is it a site crane ? TBH i dont know exactly what you're talking about, but somebody else might be able to help.

Δ=PL³ / 48 EI

YOU MUST FIND I FOR YOUR CROSS SECTION GERDER

E = 206850000 KN/M²

So you can find deflection and then you compair this deflection with allowable deflection for your application .

This should give you maximum wheel loads to design a runway girder. We design to the worst cast scenario, namely, add the following:

1. 50% of the Total weight of crane assembly (End trucks, girder(s) and accessories only)

2. 100% of the weight of the hoist mechanism

3. 150% of the rated load capacity of the hoist

4. Total all of the above and divide by the number of wheels on one end truck. (2,4,etc.,)

This should give you the wheel loading on one set of wheels. If this is an underhung crane this should give you lower flange loading to help size a runway beam.

This solves part of your problem and hopefully this will help.

If you're sizing a runway beam, we need the end truck wheel base and support centers between runway girders.

Get back to me for the rest of this.

Thanks tfamerican! I certainly appreciate that!

Yes, I do also need to design the runway beams and would appreciate your help again.

The wheel base is 4 mtrs. and the support centers are at 6 mtrs.

Thanks again!

Sometimes the CR4 website can be a bit scary.

The design of overhead crane support structures is not something that can done over a few comments, however in depth they may appear to be.

If the person who is asking the question does not know the basics of structural engineering design, then he should employ someone to do it. If they are themselves working in an engineering office, then they should sit down and do some proper design.

As an indication of what you should be designing for:

• To what are you attaching the runway beams?
• The dynamic loading (notably when the crane brakes) is generally expressed as a percentage of the SWL. This varies from one code to another.
• To what code are you designing? There is a British Standard for designing overhead cranes.
• Fatigue analysis of key points.

It is a case of the unknown unknowns which will be you're downfall.

I concur fully OMW7, the support structures must be fully checked by a qualified Structural Engineer prior to construction.

If this is under British domain, then the appropriate British Standard must be used for design.

We Yanks have the CMAA (Crane Manufacturer's Association of America) which considers and establishes crane design standards including bridge girder and runway beams. Most Structural Engineers use CMAA as a baseline for design submittals.

Then we have the Uniform Building Code (UBC) in the US which establishes structural design criteria for steel buildings, and, with the addition of accessories including the design impact of crane system (s). We also have the US partitioned off in zones for the variable severity consideration of earthquakes on a structure.

Didn't mean to scare anybody, but I fully understand your concern.

British Standard is BS 466, which is quite extensive.

Basically you need to consider that the hoist may be in the "worst" position, that is fully to one side. allow for hoist weight, load, and half of the structure, divide by two (wheels), and that gives max load.

A crane engineer.

I did 2 years of extensive experimental research on the topic, for my Masters degree,

to compare the South African crane loading code with the Eurocode.

Anyone intrested in some good reading on the topic?

Regards.

Johan de Lange

johan.delange@conisbee.co.uk