INVESTIGATORS ARE focusing on fixing bolts and connector plates for two tower cranes which crashed to the ground from the half-completed Taipei Financial Centre in Taiwan during an earthquake on Easter Sunday.
Drivers of both cranes died with three other workers as the jibs and towers plunged from around 250m. Another 23 workers were injured.
Both cranes were working on the 54th level of a steel frame for what will eventually be a 507m building, the world's highest.
Neither is thought to have been lifting at the time.
'The cranes were seated on floor beams at level 47 and braced laterally at level 51, ' said Evergreen Consulting engineer Shaw Shieh. Evergreen is the structural engineer for the project, working with architect CY Lin.
One fallen crane crushed four cars and injured a taxi driver.
'The other hit the roof of the six storey podium area on the north side of the main tower, ' said Cheng Tseng, technical manager for Taiwanese contractor RSEA Engineering Corporation.
RSEA is part of a four way consortium for the US-720M project, led by Japan's Kumagai Gumi, working with its local partner Kumagai Taiwan. The two cranes which fell are smaller 440 models of Australian made Favco luffing jib cranes on the tower. They were used mainly to lift fabricated steel elements to the top for welding into position.
'Two larger 1250DX cranes stayed in position and the north and east cranes fell, ' said Tseng.
Malaysian owned Favelle Favco is among those sending experts to examine the wreckage. Contractor Kumagai, which brought in the cranes from another project, has also sent a team from Japan.
Both cranes shook loose during a Richter 6.8 earthquake off the coast from the Taiwanese city of Hualien.
Taipei suffered a Richter 5 shaking, with accelerations reaching up to 0.98m/s 2.The cranes were fixed to the steel structure and were moved upwards every few floors to new working positions. At the time of the incident, they were waiting to lift.