INVESTIGATORS WERE this week examining the jacking procedures for the Wolff tower crane whose cab toppled 135m to the ground killing three workmen at London's Canary Wharf.
The three were extending the German built Wolff 320BF tower crane when the jib, counter jib and cab sheared off the tower and fell on to the site below.
One man is believed to have been in the cab and the other two working inside the jib when it crashed to the ground, narrowly missing another, lower level crane.
The crane was being prepared for work on the HSBC bank headquarters close to Canary Wharf 's centrepiece tower in east London.
Investigations are thought to be centering around the jacking procedures for the climbing frame on which the cab hauls itself up. They will also look at the methods for fixing new sections of tower to increase the height of the crane.
It is thought the crane erectors had nearly finished lifting the penultimate tower section when the accident happened. The crane, owned by Hewden Stewart, was on hire to Cleveland Bridge which is structural steelwork contractor on the 210m, 41 floor project.
The accident occurred just after 3pm on Sunday afternoon, at a time the site was quiet. The jib fell across an adjacent public road, smashing on to a stairwell building and into a park. The crane hook destroyed a section of the pavement in front of the Canary Wharf tower.
The HSE launched an immediate investigation with a four strong multidisciplinary team.
Mann, the German maker of Wolff cranes and Hewden Stewar t also sent investigators to the site.
A criminal investigation was launched in conjunction with the police.
No prohibition notice was served by the HSE after the accident, although the site remained closed all day on Monday.
Hoardings were being erected on Tuesday to cordon off the affected area of the site. Work was expected to resume on the rest of the site by Wednesday.
The £500M HSBC building is due to open in spring 2002.