Photo by AP/Mosa'ab Elshamy
Muslim pilgrims walk past the site of a crane collapse that killed more than 100 people ahead of the hajj Sept. 11 at the Grand Mosque.

Crane maker Liebherr has issued its findings into the collapse of a 1,350-tonne supercrane in the Kingdom of Saudi Arabia earlier this month, which killed more than 100 pilgrims and injured hundreds of others visiting the Grand Mosque for the Hajj.

The German-based firm claims that the crane was "technically faultless" and that the tip-over was caused by improper stowage prior to the storm.

“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 load and that the boom should have been lowered to the ground preventatively to avoid the tilting of the crawler crane,” Liebherr says in a Sept. 22 statement.

According to crane experts that Liebherr, the crane’s manufacturer, dispatched to the Mecca site, the crane was erected with a boom length of approximately 190 meters when a thunderstorm and sandstorm blowing winds up to 105 km/h caught the crane, which “tilted over the last support rollers of its crawler tracks.”

The crane was configured with a 114-m-long main boom and 84-m-long luffing jib, Liebherr confirms. Prior to the storm, the crane was parked outside the Grand Mosque and put out of operation.

"Previously, it had sporadically been used for assembly works," the statement says.

Liebherr adds that the accident is a tragic, global reminder to crane operators of “the influences that wind has on cranes and [the importance of] unconditional compliance with the appropriate regulations mentioned in the operating instructions.”

The Liebherr LR 11350, introduced in 2006, is one of the world's largest land-based supercranes.