Brand new worlds largest floating crane failure.

[anjum]

So where's the risk analysis? A a part is critical, can't be tested, failure would result in devastation or loss of life etc
Where was the design mitigation? Was the risk analysis done? Was the part picked up and identified? Were failure modes and impacts looked at? Was enough time or money put into FMEA?

"lessons will be learnt..."

 

[Revs1972]

Libherr build some proper crap occasionally

Their fridge freezers aren't too bad

 

[Morrisman]

So where's the risk analysis? A a part is critical, can't be tested, failure would result in devastation or loss of life etc
Where was the design mitigation? Was the risk analysis done? Was the part picked up and identified? Were failure modes and impacts looked at? Was enough time or money put into FMEA?

"lessons will be learnt..."

I would imagine they would base the design on previous installations and materials, with proven strengths, to work out what was needed to get the required SWL. Then they would increase the size/strength, usually 5 fold.

 

[Brad93]

The welding on some Liebherr cranes is atrocious. But the same could be said for most makes of heavy equipment.

 

[Robbie260]

I would imagine they would base the design on previous installations and materials, with proven strengths, to work out what was needed to get the required SWL. Then they would increase the size/strength, usually 5 fold.

Its not quite that simple but its not far off. You also have too remember most cranes have a factor of saftey of 1 is too 2, im not sure thats the right maths analogy but usually if your swl is 12 ton your crane will be designed so its guaranteed to lift 24 tones before the possiblity failure.

Edit: just too add a crane that big could have an even bigger factor of safety as in 1 is too 3 or 4 possibly even 5.

 

[Dcal]

Cranes of whatever size do not have a big factor of safety.
They can have a much lower factor of safety because they weigh the things they are lifting.

Rigging does have a big factor of safety 4, 5 even 7 times for fiber slings, but that because it can be damaged and people could still use it or it can be grossly overloaded because of misuse.

 

[Wedg1e]

It's odd how the video clip seems to miss whatever was happening prior to the jib collapsing. I'd be expecting to see the cables twanging like double bass strings but if they did, they must have stopped before the cameraman got his phone out.
I wonder if the hook only broke after it whipped back and clattered into the crane mast or something...

 

[Wedg1e]

Didn't someone come on here a few years ago wanting to make a scale model of a telescopic crane, might have been a Leibherr, that used some funky cross-section of tube? Never heard any more about it...

 

[Al Strachan]

It's odd how the video clip seems to miss whatever was happening prior to the jib collapsing. I'd be expecting to see the cables twanging like double bass strings but if they did, they must have stopped before the cameraman got his phone out.
I wonder if the hook only broke after it whipped back and clattered into the crane mast or something...

you can just make out the test barge at this side of the vessel where the main block is tied to. The main block parts and you can see the now free double block raising up quickly in front of the crane as the jib folds back on itself. Basically newtons 3rd law in full flow here! the force of letting go acting completely in the opposite direction and folds the jib over backward.

Kind of my line of work this, albeit with the smaller MacGregor/TTS/Hydramarine knuckleboom cranes. Believe it or not and as Dcal mentions, the safety factor decreases significantly the heavier the equipment. the normal LOLER safety factors of 3/5/8 etc reduces to around 1.2 or so (if my memory serves) depending on the classification society when you get up into the 1000's of tons.

 

[Robbie260]

Cranes of whatever size do not have a big factor of safety.
They can have a much lower factor of safety because they weigh the things they are lifting.

Rigging does have a big factor of safety 4, 5 even 7 times for fiber slings, but that because it can be damaged and people could still use it or it can be grossly overloaded because of misuse.

Interesting learn something new everyday. You would think it would go the other way but I suppose it just become cost prohibitive at some point. We generally dont go around weighing stuff before lifting it, having said that we do know roughly what our engine componets weigh, a cylinder head weighs somewhere in the region 12.3 tones the engine room cranes are usually rated to 12.5 so there isnt much room for error if something is stuck together. The cranes are tested in drydock every 5 years too 1.5 times the safe working load always assumed they could take a bit more than that because it seemed too be a bit silly to test it too its absolute maximum but just talked too the cheif engineer and our factor of safety is indeed 1.5.

 

[bill_gj]

oops someone's going to get a kick up the ring mind u u can allways blame it on the computer

Computer said - bo#locks!

 

[andyclimax]

i think the nut that holds the lower part of the hook has stripped off the shank. looking at the picks it appears to be a tapered tread . i have seen it on another big crane hook but can't remember where or when .

 

[eddie49]

Didn't someone come on here a few years ago wanting to make a scale model of a telescopic crane, might have been a Leibherr, that used some funky cross-section of tube? Never heard any more about it...

It was 9 years ago, made by rebekah_harper of RAF Waddington:
https://www.mig-welding.co.uk/forum/threads/liebherr-ltm-1250-scale-boom.26072/
The tube shape is called oviform:
https://freecranespecs.com/Liebherr-LTM-1250-1(3).pdf

 

[mtt.tr]

I dont think the hook broke, looking at the pics it looks like the hooks swivel housing has failed.

Bob

Thats what it looked like to me

 

[Stingray]

Hook swivel failure!

 

[Shox Dr]

I see there’s a short documentary on youtube about the Alphen aan de Rijin

 

[pressbrake1]

Hook swivel failure!
View attachment 228141

In that case I’m thinking big stress raiser caused by(poor) machining

 

[jimbo84]

Somebody mentioned earlier they were weight testing it with a 2000t weight...hasn't the weight test done it's job and proved it's not fit for purpose? Shame it wrecked the crane but better that than it failing at a more critical time.

The barton lift bridge snapped some cables and dropped to the deck, during a weight test I believe, again better then than with a load of people under it.

Cranes of whatever size do not have a big factor of safety.
They can have a much lower factor of safety because they weigh the things they are lifting.

Rigging does have a big factor of safety 4, 5 even 7 times for fiber slings, but that because it can be damaged and people could still use it or it can be grossly overloaded because of misuse.

Entertainment rigging is even higher at 10:1 safety factor in a lot of venues.

 

[Pete.]

Hook swivel failure!
View attachment 228141

Got ripped off by a Kraken

 

[Wedg1e]

you can just make out the test barge at this side of the vessel where the main block is tied to. The main block parts and you can see the now free double block raising up quickly in front of the crane as the jib folds back on itself. Basically newtons 3rd law in full flow here! the force of letting go acting completely in the opposite direction and folds the jib over backward.

Kind of my line of work this, albeit with the smaller MacGregor/TTS/Hydramarine knuckleboom cranes. Believe it or not and as Dcal mentions, the safety factor decreases significantly the heavier the equipment. the normal LOLER safety factors of 3/5/8 etc reduces to around 1.2 or so (if my memory serves) depending on the classification society when you get up into the 1000's of tons.

Yes, I realised it was probably trying to lift the test piece (although you can't see any slings, chains, swivels or other means of attachment that I can make out) but why the video only started to be shot after the damage had already occurred was the puzzler. If it was so video-worthy, why not shoot the whole thing, was my point.