The statement explained that two Wolff cranes had been used at the same position on the site: a Wolff 100 B, working from December 2008–April 2009, and the 500 B, which worked on the site from April until the time of the accident.
The Wolff 500B crane which overturned is now impounded by the HSE with sections of interest due to undergo chemical, metallurgical and structural tests over coming months. The base is subject to an order to leave undisturbed; the HSE will be overseeing the planned excavation and investigations once the detail of the process has been finalised with the HSE.
Investigations to date have confirmed that the tower crane base was designed and built around the use of a Wolff 500B luffing crane and the loadings, base and tower supplied for the Wolff 500B crane. Prior to the arrival on site of the Wolff 500B luffing crane a Wolff 100B luffing crane was erected on the tower with a reducer section and utilised during the early part of the project (January 2009-April 2009) for the in-situ concrete works.
This process had been a planned operation. The foundation had been checked and signed off prior to erection. Furthermore, both cranes were subject to load tests and independent thorough examinations (December 2008 for 100B & April 2009 for 500B), as well as standard weekly visual inspections of the crane which included the foundations.
The cause of the incident on 6 July is yet to be established and Bowmer & Kirkland Ltd is unable to offer any further comment whilst the investigation is ongoing.
