Crane manufacturer Liebherr Group has identified during preliminary investigations that hook failure led to the crane collapse on DEME Offshore’s Orion 1 vessel at Rostock port in Germany on 2 May.
The responsible authorities and experts investigating the accident “unanimously agree” that a broken crane hook on the HLC295000 unit was the cause of the accident, the company stated.
The crane hook was purchased from an external supplier.
“A design or production error of the Liebherr crane can therefore be excluded,” said the company.
Carrying out an overload test is a typical procedure for the industry, whereby the crane is tested for its maximum lifting capacity.
The overload test for the HLC295000 should have been carried out through the hoisting of a barge. The incident occurred at a load of around 2600 tonnes causing a “chain reaction” that led to the accident, stated Liebherr.
The accident has no effect on day-to-day operations at Liebherr-MCCtec Rostock, said the company.
According to initial estimates, the damage amounts to a high double-digit million figure.
“The exact reasons as to why the hook did not withstand the load are unclear at this stage of investigations,” Liebherr stated.
During the accident two people were injured and had to be taken to hospital for treatment and a further 10 were treated by paramedics on site.
Liebherr-MCCtec Rostock managing director Leopold Berthold said: “At this point we wish the injured persons all the best and hope for a full and speedy recovery.
“Considering the extent of the damages, we are above all thankful that it did not cause more personal injuries. Our priorities currently lie in fully supporting the investigating authorities in order to contribute to the quickest possible clarification of the accident.”
Orion 1 was due to install jackets at the 950MW Moray East wind farm off east Scotland next month but DEME said it is now looking for a replacement for the work.