19.04.2004

Mystery surrounds fatal Ohio crane collapse

The cause of collapse of a 915 t, Italian-built launching gantry/crane in Toledo, Ohio, US last February is still unknown following analysis of its key components.

On February 16 this year, one of a pair of 12 m high, 95 m long, 915 t Poalo de Nicola gantry cranes owned by Fru-Con construction corporation, an affiliate of Germany’s Bilfinger-Berger construction company, collapsed while lifting a 120 t beam over the northbound lanes of Interstate 280 near Toledo, Ohio, in the US.

While four construction workers were killed and four seriously injured, no accidents were reported among the public travelling on the bust stretch of road below.

The two cranes were purchased new in 2002 from the Italian specialist crane producer Paolo de Nicola, specifically for the contract, at acost of €6 million. The cranes were almost identical to two that had successfully completed a similar job in Taiwan. The design and concept of the crane were tried and tested, and the crane that collapsed appeared to be working well within its limits when the accident occurred.

First inspections are said to have found cracks in some of the crane's structures, although it is not known whether these were caused by structural failure or a result of the crane collapse. The critical parts were sent to Lehigh University laboratory, where Dr John Fisher has been heading up the analysis.

Lehigh is a well respected engineering school in Pennsylvania with a reputation for carrying out analytical work of this type, having been involved in the analysis of some of the World Trade Centre's structural parts after the September 11 disaster.

Initial reports form Lehigh were said to be inconclusive but are still not complete. In the meantime, construction has restarted on the bridge, but alternative lifting methods are being used while the tests continue. All lifting over public traffic at the site has been discontinued.

The bridge construction was running way ahead of schedule; thanks in part to the role that the two special cranes were playing. The loss of one crane and the damage caused by the accident though is likely to delay the completion of the project by over a year.

Paolo de Nicola SpA of Cittadella (Padova), near Venice, was established in 1945 and specializes in a wide variety of gantry-type cranes for building bridges, as well as building harbour side cranes and other specialist lifting devices. Specialists from the company are understood to have flown in immediately after the accident was reported.