Liebherr has issued a statement after inspecting the LR11350 that went over in Mecca on September 11th killing over 110 people.
The company statement said that following an on site inspection by its experts, the crane was "technically faultless" and confirmed that the crane was improperly stowed for the expected weather conditions – confirming the initial Saudi investigation and report for the king.
The statement added: “The operating instructions of the LR 11350 and the associated Wind Speed Charts show that the crawler crane could not withstand such a high wind loading and that the boom should have been lowered to the ground preventatively to avoid the tilting of the crawler crane.”
The company has also confirmed that the crane was rigged with 114 metres of main boom, topped with an 84 metre luffing jib - giving a tip height of just over 200 metres. The boom and jib were both left in the fully raised position overnight to face a sand and thunderstorm with heavy rain and winds of between 80 and 105 kph (50 and 65 MPH). “The high winds caused the crane to tilt over the last support rollers of its crawler tracks.”
The crane had only been used sporadically prior to the incident and was left out of service with boom and jib both fully elevated when all of the cranes instructions clearly state that when such conditions are expected the jib and ideally the boom should be lowered.
The crane boom has been cut into sections and removed from the area, and repairs to the structure started. Nine Bin Laden engineers and managers are being interrogated over the incident.
This was a tragic incident and almost certainly the worst crane incident in living memory. It is however very refreshing to see both the Saudi authorities and the manufacturer work in a co-operative manner and issue their findings so quickly. It will serve as a stark reminder and warning for all crane owners and operators on the need to follow out of service instructions and to consider these when rigging the crane, as well as each evening before leaving the crane.
Hopefully a few regulatory authorities around the world will sit up and take notice of how it should be done.