Nasty crane collapse London

[ronan]

One of the things that now causes so many scaffolding collapses in high winds is the fact they now have to cover the whole structure in safety mesh. It increases the wind loading massively.

Yes i believe that the wind has a huge affect on cranes too. Anything over 4mph and it can be dangerous.

 

[4String.]

Yes i believe that the wind has a huge affect on cranes too. Anything over 4mph and it can be dangerous.

Portakabin near York, (the true capital city of England ), have some seriously large Goliath cranes in their yard, which didn't have locks on the long travel.

Many years back, the wind got up and not surprisingly pushed them down the tracks. They hit the end stops and not surprisingly again, tipped over. On top of a line of cars in the car park. About 10minutes before knocking off time . Not long after all the metaphorical dust had settled, locking end stops were fitted . It was incredible that no one had thought it might happen, but happen it did.

 

[Pete.]

One of the things that now causes so many scaffolding collapses in high winds is the fact they now have to cover the whole structure in safety mesh. It increases the wind loading massively.

Scaffold sheeting is (supposed to be) designed to come off in high winds. The number and placement of the little elasticated ties is part of the design (or specification). When the wind exceeds a set amount the sheet ties let go and the sheeting comes partially away relieving the wind load. That's why it's important to not over-tie the sheets.

It's also one of the reasons why the scaffold MUST be inspected after any high wind.

Time was that they get up on the scaffold with a knife and slash the sheeting to get the same effect.

 

[Pete.]

Yes i believe that the wind has a huge affect on cranes too. Anything over 4mph and it can be dangerous.

There's no crane with such a low limit, but yes they are limited by wind speed. Each crane has it's own limit given for ground-level with a reduction factor as you go up - so many % for so many metres in height. The limit is reduced (to about half I believe) if it has to lift humans. There's also gusts to consider. If the operator gets a gust that exceeds the wind limit he has to wait a period (usually 10 minutes) to see if it happens again. If it does, the clock is reset and he waits again.

 

[Agroshield]

These crane collapses seem to be incredibly common, worldwide.

That is rather a bizarre thing to say. If you want to use YouTube for your statistical analysis, try replacing 'crane collapses' with 'car crashes' or 'plane crashes' in your search. Compare and contrast results.

A compilation video of many different types of crane, taken over a period of many years, in numerous countries all with differing legal frameworks, different enforcement policies and different cultural attitudes does not provide meaningful data.

 

[Matchless]

In fairness that poor little house stood up pretty well considering!

House? rabbit hutch...........

 

[Beatroot]

I live just around the corner in bow, we have had high winds and a lot of rain in a 24hr period

 

[jimbo84]

Is there a reason why they now seem to mainly use Luffing jibs, it always used to be the T type of crane (not sure of its correct name).

It sounds counter-intuitive but one of the most highly stressed conditions of a crane (and greatest load on its base) is its out-of service mode. No weight on the hook but the back ballast is trying to bend it backwards. Maximum bending in the mast. Maximum weight on one pad. As the hook load comes on, the mast bending goes to zero (balanced - the way it needs to be if climbing the crane) and then increases to a maximum at full load.

There was a tall one in Manchester years ago it was the tallest one I've seen that wasn't tethered to a building, just freestanding on its base, the old T type, the builders went bust and it was just sat there for a very long time, it was so tall it had a visible bend backwards towards the weights, in the end some official body had something to do with it being taken down as it was condemned.

In fairness that poor little house stood up pretty well considering!

I was thinking the same. I imagine the whole row will be demo'd now. Can't even begin to imagine what goes through your head after an incident like that, whether it's your house or the neighbours.

 

[jimbo84]

House? rabbit hutch...........

It's still somebodies home/s that have been sliced in half.

 

[Shox Dr]

Is there a reason why they now seem to mainly use Luffing jibs, it always used to be the T type of crane (not sure of its correct name).

I dont know but Cost and speed of erection will be the key factors. Basically profit

 

[Matchless]

It's still somebodies home/s that have been sliced in half.

Point was the sort of thing that they put up these days for housing, looks like a house when finished but built out of OSB and matchwood, lifespan of?

 

[jimbo84]

Point was the sort of thing that they put up these days for housing, looks like a house when finished but built out of OSB and matchwood, lifespan of?

Misinterpreted your meaning, fully agree on that front

 

[mike os]

Considering the number of cranes in daily use the number of collapses is remarkably small. By their nature any collapse will be spectacular.

In this case it looks like a failure of the anchor system but that may well be the result of the column overturning rather than the cause.

Maintained and used correctly these are a spectacular engineering achievement considering their space and operational capabilities,

 

[jsf55]

Latest update, that looks a heavy load ?
https://www.theconstructionindex.co.uk/news/view/woman-killed-in-london-tower-crane-collapse

 

[Matchless]

Watts Grove development, the UK’s first mid-rise cross laminated timber (CLT) housing development made of prefabricated modular units. Work started on site in June 2018.

 

[TechnicAl]

Portakabin near York, (the true capital city of England ), have some seriously large Goliath cranes in their yard, which didn't have locks on the long travel.

Many years back, the wind got up and not surprisingly pushed them down the tracks. They hit the end stops and not surprisingly again, tipped over. On top of a line of cars in the car park. About 10minutes before knocking off time . Not long after all the metaphorical dust had settled, locking end stops were fitted . It was incredible that no one had thought it might happen, but happen it did.

We used to supply them....they would cut a fart in half

 

[dobbslc]

@Brad93 I can only imagine it's race to the bottom, Cheapest job wins & safety goes out the window

Since "lockdown" the race has got much faster! All the builders are trying to catch up on lost time. There will be more accidents.

There's no crane with such a low limit, but yes they are limited by wind speed. Each crane has it's own limit given for ground-level with a reduction factor as you go up - so many % for so many metres in height. The limit is reduced (to about half I believe) if it has to lift humans. There's also gusts to consider. If the operator gets a gust that exceeds the wind limit he has to wait a period (usually 10 minutes) to see if it happens again. If it does, the clock is reset and he waits again.

I regularly here the wind speed alarms going off continuously, they don't normally stop.

 

[fizzy]

Point was the sort of thing that they put up these days for housing, looks like a house when finished but built out of OSB and matchwood, lifespan of?

I would never ever ever buy a new build!

 

[Pete.]

I regularly here the wind speed alarms going off continuously, they don't normally stop.

That might be the 90% alarm. It lets everyone know when the crane is at 90% capacity.

 

[dobbslc]

I've seen it with the chains blowing in the wind and nothing loaded