Can someone work out a beam strength for me please

[fizzy]

Looked for online calculators but none of them seem to ask the obvious - like the size and thickness etc!

I beam gantry

2000mm unsupported length
140mm wide
210 height
12mm thick top and bottom
web 10mm thick

Just wondering what sort of weight it would take at centre

 

[addjunkie]

Did you try this one

Free Beam Calculator | Civils.ai

Free beam moment, shear force and deflection calculator

civils.ai

 

[Agroshield]

Here: https://calcresource.com/statics-simple-beam.html which requires an I-value, from here: https://calcresource.com/moment-of-inertia-doubletee.html

None of them will tell you 'what weight it will take'. They will tell you the midspan deflection under a point or distributed load. It is up to you to decide if that deflection meets your requirements. You can look up in, for example, the building regulations what is considered acceptable (span/360 springs to mind).

 

[Agrismith]

Use the blue book to find the bending moment of a given beam section then check if it matches the required figure from the free online calculators.

https://www.steelforlifebluebook.co.uk/

 

[fizzy]

Why can't they just make a simple calculator where you put in the dims of the beam and it tells you the load rating?
Most of these calculators tell you what force is acting on the beam. I know that. I need to lift 3000kg.

 

[Agrismith]

Why can't they just make a simple calculator where you put in the dims of the beam and it tells you the load rating?
Most of these calculators tell you what force is acting on the beam. I know that. I need to lift 3000kg.

The blue book charts I posted above do that. It has to be a chart as you select your bending moment and then scroll through to find the smallest section that gives the acceptable deflection for the span you want. I can use it so it really is not that difficult to use.

 

[8ob]

Looked for online calculators but none of them seem to ask the obvious - like the size and thickness etc!

I beam gantry

2000mm unsupported length
140mm wide
210 height
12mm thick top and bottom
web 10mm thick

Just wondering what sort of weight it would take at centre

I don’t think you will find what you are looking for Fizzy, there are no simple laymen calculators for things like this. It’s about acceptable deflection and limiting deformation, fwiw I would happily stand under that beam if there was a 3 ton weight on it as long as the ends were capped.

Bob

 

[Agroshield]

Why can't they just make a simple calculator where you put in the dims of the beam and it tells you the load rating?
Most of these calculators tell you what force is acting on the beam. I know that. I need to lift 3000kg.

Think about what you mean by beam. There are beams made from solid, with a rectangular (square) shape, circles (rod or tube), ovals (bicycle tube), etc., etc. Each country has its own standard rolled sections. European rolled sections are different to UK ones. Without looking it up, I do not know if the dimensions you cite above are a standard rolled section or something that is fabricated from plate. No calculator can hope to cover all these possibilities.

However, whatever weird shape the beam might be, the mechanics of its bending is very simple, depending only on three things: the load applied, the material (E value) and the geometry (I value). The calculator above will let you put in the dimensions you have and calculate the I value for you. You can look up the E value for steel.

There is no such thing as a load rating for a beam. For more than 90% of applications, the ultimate load (i.e. the load reached where the material exceeds its elastic limit, leading to permanent deformation) is never reached. There are many failure modes of beams, and most of them occur well below the ultimate load. You can look up lateral torsional buckling (for a really long beam, it buckles at 90 degrees to the applied load - the top flange goes sideways). There is also web buckling (short span and tall aspect ratio). For a particular beam, the design code to which you are working will lead you through steps A-Z which check all the possible modes and give you a 'yes' or 'no' answer on whether the load case and beam specification you propose meet code or not.

As said above, the most generally used one for an 'average' or 'simple' beam is allowable deflection. This is because when you walk across the upstairs floor of your house, you feel uncomfortable when the middle of it sags too much. There is absolutely no way the floor will collapse but it is not deemed an acceptable characteristic of the structure if it deflects too much.

So put your numbers into the calculator, see what deflection you get for 3000kg midspan point load, compare it with span/360 and make a judgement whether you are comfortable with that.

 

[Pete.]

Beams and columns are mostly UB or UC (universal beam or universal column). If it's new, it's probably going to be rolled to one of those standards so working-out should be easy with the relevant software. Anyone who tried to roll steel differently would find themselves short on customers as the designs would be difficult.

If it's very old steelwork, it will be a lot heavier for it's section and not as strong for a given section but you'll see that easily by the shape. UB and UC top and bottom flanges are parallel sections the old stuff they are tapered towards the edges.

 

[fizzy]

I don’t think you will find what you are looking for Fizzy, there are no simple laymen calculators for things like this. It’s about acceptable deflection and limiting deformation, fwiw I would happily stand under that beam if there was a 3 ton weight on it as long as the ends were capped.

Bob

Thanks for that.
I have an old lifting gantry which is rated to1.5 ton. But it looks far more substantial than ones I have seen online rated to 5000kg. They have a bigger span as well.
The steel wheels look much better quality as well but I would jack them as a precaution. It's not like I will lift loads that heavy all the time but i may get my hands on a 2.5 to 3 ton lathe.

 

[Milkybars]

@fizzy seriously do you just post this stupidity for ****s and giggles
If it's rated for 1.5 Tonne it will have quite a margin of 'miss use' built into that figure, but I somewhat doubt that included double the rated load

 

[Morrisman]

Why can't they just make a simple calculator where you put in the dims of the beam and it tells you the load rating?
Most of these calculators tell you what force is acting on the beam. I know that. I need to lift 3000kg.

That beam will easily hold 3000kg. What's more important are how the ends are mounted.

 

[bletchmonster]

@fizzy seriously do you just post this stupidity for ****s and giggles
If it's rated for 1.5 Tonne it will have quite a margin of 'miss use' built into that figure, but I somewhat doubt that included double the rated load

You could just suggest you don't think it's a good idea!
Too many folk on here wading in making it personal these days.

 

[fizzy]

You could just suggest you don't think it's a good idea!
Too many folk on here wading in making it personal these days.

Indeed so - I never make it personal or rubbish people's comments!

 

[fizzy]

@fizzy seriously do you just post this stupidity for ****s and giggles
If it's rated for 1.5 Tonne it will have quite a margin of 'miss use' built into that figure, but I somewhat doubt that included double the rated load

Yes I am thick - stupid and ignorant

 

[grim_d]

@fizzy seriously do you just post this stupidity for ****s and giggles
If it's rated for 1.5 Tonne it will have quite a margin of 'miss use' built into that figure, but I somewhat doubt that included double the rated load

3 tonne is the load margin for the beam with a 1.5 tonne hoist on it.

If the man wants to lift a 3 tonne load with a 1.5 tonne hoist then that's entirely his prerogative provided it's just him and in a personal capacity.

He's a big boy, I'm sure he's aware of the risks of doing so.

 

[fizzy]

@fizzy seriously do you just post this stupidity for ****s and giggles
If it's rated for 1.5 Tonne it will have quite a margin of 'miss use' built into that figure, but I somewhat doubt that included double the rated load

This British engine crane is rated at 500kg - a lot more substantial than your typical Chinese 2 ton one!
So in this case I am sure it will lift 4x it's rated load.
Old British equipment was very much over built and under rated!

 

[James1979]

I am not a lifting engineer, nor a beam-ist so ignore this if you want…..

It may have been down rated for a purpose before you got it?

I’ve seen them on ships that are obviously huge and would lift proper weight have an swl of 500kg because they’re for a specific task, or to stop someone doing something stupid.

There used to be (I think it’s gone now?) a rule that sub a certain weight (1000kg?) was exempt. That’s why you see swl 1t on older diggers with pad eyes on the end of the dipper. They’ll lift far more but it’s to do with that rule. Your beam may be similar.

I had one in the old workshop. SWL 1t. We had 5t on it once. It was ex airfield and was for lifting rotor knuckles off helicopters. That sole job. It was tall and skinny which may have been more related to the 1t than it’s actual dimensions as a beam? I shortened the legs to get in my old workshop and it’s still there, I think.

With beams, lifting or otherwise, it’s all in the ends.

Edit. When I did my last rigging slinging course, the safety factor of an SWL was 5. You need to down rate that further for some things but it’s a handy rule of thumb. Ie a 3t strip in good condition will fail at 15t or thereabouts

 

[fizzy]

I am not a lifting engineer, nor a beam-ist so ignore this if you want…..

It may have been down rated for a purpose before you got it?

I’ve seen them on ships that are obviously huge and would lift proper weight have an swl of 500kg because they’re for a specific task, or to stop someone doing something stupid.

There used to be (I think it’s gone now?) a rule that sub a certain weight (1000kg?) was exempt. That’s why you see swl 1t on older diggers with pad eyes on the end of the dipper. They’ll lift far more but it’s to do with that rule. Your beam may be similar.

I had one in the old workshop. SWL 1t. We had 5t on it once. It was ex airfield and was for lifting rotor knuckles off helicopters. That sole job. It was tall and skinny which may have been more related to the 1t than it’s actual dimensions as a beam? I shortened the legs to get in my old workshop and it’s still there, I think.

With beams, lifting or otherwise, it’s all in the ends.

The ends are VERY solid - I will post a pic later

 

[Agrismith]

View attachment 359314

This British engine crane is rated at 500kg - a lot more substantial than your typical Chinese 2 ton one!
So in this case I am sure it will lift 4x it's rated load.
Old British equipment was very much over built and under rated!

They can give ridiculous load ratings on
Engine cranes as they are cantilever. They can perfectly acceptably give a load rating of a point on the beam that is so close to the kingpost that you can't ever actually use it. Whereas a gantry crane with a block and tackle doesn't derate itself. Same is true of big cranes.
Our grab lorry has a 12t crane fitted but you would be hard pressed to pick up 1.5t with it.