THE CRANE collapse which killed three site workers at the weekend was the third major safety scare involving cranes on Canary Wharf in the past six weeks.
The three men had been working on the new HSBC skyscraper being built by Canary Wharf Contractors.
Earlier this week it emerged that a crawler crane had also toppled over on the adjacent Citibank site on May 9.
Construction News has also learned of a third incident on April 4, again at the Citibank site - when a welding set plunged up to seven storeys, after a crane cable snapped without warning.
A safety audit of cranes on both sites in London's Docklands was being carried out as Construction News went to press.
Three men died when 'Tower Crane 3' collapsed on Sunday while it was being raised, in what should have been a routine operation.
They were Peter Clark, 33, from Southwark in London, Martin Burgess, 31, from Castleford in West Yorkshire, and Michael Whittard, 39, from Leeds. The inquest into their deaths opens today, and police have also launched their own investigation into their deaths.
The three men had been been jacking up the cab, on the 26th floor, when the mast of the crane buckled and snapped in two.
The crane was 'self-climbing', which allowed it to rise with the building, with the help of a climbing frame.
This was attached to the crane through four hydraulic jacks, which were used to lift the jib and cab, raising them to their new height.
As the jib and cab are temporarily raised, the new tower extension is then lifted in by the crane through the open front section of the climbing frame and fixed in position.
When the jacks are released, the weight of the jib and cab is then transferred to the new section.
Early speculation on the probable causes of the collapse has focused on whether the jib of the crane was locked before the raising operation and whether the hydraulic jacks responsible for the lifting the structure were in good working order.
The German-made Wolff Hydro 32BF crane was on hire from Hewden Stuart.
A Hewden spokesman confirmed that the crane which collapsed on Sunday was one of 70 similar cranes that the company has on hire currently, throughout the country. Wolff has sent two engineers from Germany to assist with the investigation. A Canary Wharf spokeswoman said: 'During a routine procedure involving raising the working level of the crane, the crane jib collapsed, killing three men who were erecting the top section of the crane.'
The company said it was fully co-operating with the investigation but refused to comment on the circumstances of the collapse.