10.05.2013
Crane overturns on wind farm
A 500 tonne crane overturned early on Wednesday morning while relocating on a wind farm in Fitjar, to the south of Bergen in western Norway,
The crane a 500 tonne Liebherr owned by Nordic Crane, had completed a lift installing the blades on a turbine and was being moved during the night to another location, with luffing jib counterweight and Y-Guy super lift system in situ when it lost stability and overturned.
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The overturned crane
We understand that no one was hurt in the incident and the damage was limited to the crane. The cause of the overturn is being investigated but we understand that initial blame is being directed at the condition or design of the tracks/roads
Ryan
No matter where the CG of this crane is, it does not have a chart in any configuration moving with the outriggers fully retracted like pictured here. What a waste of a great crane.
Another accident while relocating a fully rigged crane... it wil not be the last one i guess.
I know that it's cheaper to relocate a crane for another job that way but what is the price now???
Moving a rigged crane is possible at hard and flat ground, not on poor tracks.
It's like Mr. Ponsonby says:in this case the crane have an abnormally High Centre of Gravity wich means that , when the crane is moving on tires, it will be verry unstable on poor or soft underground or tracks...
This didn't have to happen ... too bad.
Keep it safe guys!
Hurts me to see a lovely crane broken, knowing the expensive damage sustained and the frequency of such accidents, may be interesting for Cranes & Access to feature how these machines are repaired by the OEM's and at what cost !
Good Morning Mr Editor,
The Liebherr LTM.1500.8.1 Hydraulic Telescopic Crane is an excellent product and very safe too. However as this Norway incident confirms once again, even a Safe Crane can be tipped over by an Unsafe Act. The Explanation given is " The condition or design of the soft tracks/roads " but is this truly the Root Cause, or simply the Effect ?
The Mfrs Duty Charts are a great source of Facts.... and close scrutiny of the LTM 1500.8.1 Chart reveals that....
1. The Total Weight of this Excellent Crane is 96 tonnes GVW, which due to its Eight Axles means 12 tonnes per axle, or 6 tonnes imposed load per tyre.
2. When Rigged for a Lift with Long Luffer and Y Guy system fitted, the Mfrs recommended Ballast is 165 tonnes, thus increasing the Gross Weight to 261 tonnes GVW which is 32 tonnes per axle, or 16.3 tonnes Ground Bearing Pressure per tyre.
3. When moved Free on Wheels, the Main Boom must be fully retracted to keep the Luffer as Low as Possible. However this means that the Boom is still elevated to circa 28 degrees meaning the Y Guy System plus Luffer A Frames are now nearly vertical. The effect of this is quite dramatic, for not only would this Crane then have an abnormally High Ground Bearing Pressure (GBP) of 32 tonnes per axle, it would also have an abnormally High Centre of Gravity, calculated at circa 8 metres above ground level.
So it is my submission to the Chief Executive (CEO) of Nordic Cranes that the explanation given to him of 'Soft Tracks or Roads' is simply the effect, for the Root Cause of this dangerous rollover incident was moving this Crane with an Abnormally High Centre of Gravity, compounded by an Abnormally High GBP of 16.3 tonnes per tyre. All of which made this overnight move on poor quality Roads/Tracks a Highly Dangerous Act. It is my further submission to the CEO of Nordic Cranes as this is his Second Major Crane Incident in only 8 months, ( See Oct 2012 Incident) that he starts an Ongoing Crane Safety Programme ASAP, with the First Group of Trainees being all Directors and Managers of Nordic Cranes, as someone in this Group ordered this Crane to be moved Free on Wheels in this fully rigged condition. The Training Programme should incorporate the following base subjects as the foundation of Safe Lifting Operations in the future...
4. How to Calculate Ground Bearing Pressures ?
5. How to Calculate the Rising Centre of Gravity in a Fully Rigged Crane complete with Luffer, before moving it Free on Wheels on poor quality Roads or Tracks ?
6. How to produce an Accurate Risk Assessment, based upon all foreseeable Hazards, using E.R.I.C. (ERIC) as the most important guideline ?
That way he will not have to witness his very Expensive Crane Lieing on its side in Norway and we will not have to read such untruths as ' The condition or design of the tracks/roads' : When in reality the ground giving way under the enormous GBP of the Tyres of this Crane was simply the effect, not the Root Cause of this dangerous Incident. Fortunately No-One was Killed on this occasion, but all too often it is Fatal and normally some innocent person as well.
Mr Chief Executive of Nordic Cranes, please remind your Colleagues that Crane Safety is everyone's responsibility, not just your and mine ?
Kind Regards
Mike Ponsonby BA