The main stumbling block in the programme, Richardson believes, came from Multiplex's decision to replace its steel subcontractor Cleveland Bridge UK with Hollandia (NCE 8 July 2004). 'The steelwork was already behind programme and Multiplex hoped that by switching to Hollandia, and using more of a partnering arrangement, the job could be done more quickly.' It was diffi cult for WNSL to interfere with Multiplex's decision, but experience told him at the time that it was perhaps a bad move.
A few other mistakes have hindered the project: pouring the wrong strength concrete in the arch bases, which added weeks to the work, and having to replace 11 of the tubular steel 'straws' making up the main arch before lifting.
'C40 had been specified for the arch base, but Multiplex decided to use C60 [for greater assurance]. But after pouring the concrete for the second arch base, they realised they were still using C40, ' says Richardson.
In the case of the steel arch elements, Richardson recalls that the replaced straws were only slightly out of tolerance, but Multiplex took the view that they should be replaced - 'it was the responsible thing to do'.