crane fall in to canal

[Johny Walker]

Updated: Crane falls into canal at Apperley Bridge (From Bradford Telegraph and Argus)

 

this could take a bit of getting out ,

Edited February 1, 2013 by Johny Walker

[Pat Ferrett]

It says it weighs 64 tonnes but can lift 90 have they got it wrong or is that possible ?

[muttley9050]

Of course its possible, depends where the wight is posistioned, not at the end of the jib of course, plenty of outriggers to counter theweight. However mostcranes are rated to carry significantly less than they weigh. I personnally think they made mistake.

James

[woody paul]

Looks like he miss judged the path as hook is still on front

[muttley9050]

Well spotted, says in blurb that the tow path gave way.

Is it going to end up like the we never learn thread?

[monkeybusiness]

I know nothing about cranes but I was on a demolition site once and a 1000 tonne (I think) crane turned up along with a trailer full of weights that got loaded onto the counterweight. There is no way that machine could have weighed more than 200 tonnes all up. I don't understand how it works and may well be very wrong though...

[muttley9050]

Found this:

A particular crane might weigh 3 T, plus a counterweight of 5 T, for a total of 8 T, all of which is located behind the front of the crawlers. Let's say the machine is 5 m long. The center of mass of the thing would be located about 4 m behind the front of the crawlers.

 

Let's say that we're trying to lift 16 T, which is twice the weight of the machine. Provided that the load mass was less than 2 m in front of the machine, then there'd be no problem.

 

As long as:

 

(total mass of crane) x (distance of crane's center-of-mass from front of crawlers) is less than (total mass of load) x (distance of load's center-of-mass from front of crawlers)

 

you're OK.

 

The above calcs ignore the weight of the jib, but that can be allowed for as part or the load mass and subtracted from the crane mass.

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[Breezeblock]

its a sales pitch it will only lift that at 0 radius on no extension

[Rupe]

The tonnage of a crane (the amount it can lift) is based on <1m of reach. So yes a crane can lift more than it weighs straight up into the air. As soon as you go out sideways the amount it can lift goes down very fast.

 

So a 200t crane may only lift 500Kgs at full sideways reach. This is why tree work with crane sis risky, instead of putting a load down away from a crane its picking an unknown load up at a distance away from itself.

[Rupe]

I thought it might be zero radius, wasnt sure so put <1m to make the point but yes I think your right, its a thoeretical amount it could lift straight up.