Such a crucial role was taken up by two engineering consulting firms Holmes Consulting and local experts Strata Group with Red Steel providing 163 tonne of structural steel across the Opera House, Functions on Hastings and the Municipal Building.
Holmes Consulting completed the structural designs for the Opera House and the Municipal Building, while Strata Group was the on-the-ground consulting firm that has regularly checked off that what was designed has been implemented by the Gemco construction team.
Strata Group then stepped up and carried out the structural design for the new Functions on Hastings building (the former Plaza) as well as being the lead firm in reviewing the construction process for the redevelopment undertaken by Gemco.
Structural engineer David Plowman has made the 200-metre walk from Strata Group’s office in Queen Street to Hastings Street many times over the past couple of years.
“Being local and so close to the project has really helped. We would get a call from Eddie at least once a week, but sometimes up to four times a week, and we could walk across and check things quickly.”
The role comes with significant responsibility as the buildings are of national heritage status, together with the fact that Hastings ratepayers are footing much of the bill to reopen the Opera House.
“It’s really exciting to see the Opera House come back to life. A lot of what has been done is behind the walls to ensure it is standing strong well into the future. In part, most of what has been done people won’t even notice; however, we’ve kept some of the structural steel exposed in one of the bathrooms so that people can get an idea of the complexity of the work.”
Bob Hawley, managing director of Red Steel, says 95 tonnes of steel was used, a key element to the project.
Structural steel bracing was integral to the project, with bracing diaphragms installed at various levels – both internally and externally – to provide the lateral support necessary to meet design parameters.
Bob says the challenge was in the execution – installing the bracing without removing the roof.
The solution required precision planning and careful execution as the steelwork had to be craned through holes cut in the roof and the walls of the building, then manually lifted into place with custom- made rollers, gantries and chain blocks.
“We had to devise innovative temporary lifting systems to manipulate the large steel components into these tight spaces.”
Red Steel was a finalist in the 2019 Steel Construction NZ Steel Awards $1.5 million to $3 million category for the work they did on the Opera House.
The judges’ comments were: “This redevelopment showcases a stunning use of steel, creating an aesthetically pleasing, open structure. The strong architectural concept was followed through via contractor engagement and the methodology around fabrication and installation was very impressive.”