Waitaki Bridges Replacement for NZ Transport Agency, Waitaki – McConnell Dowell Constructors Limited
The Waitaki Bridges Replacement by McConnell Dowell is a fine example of what can be achieved by Client, Contractor and stakeholders working together to provide new infrastructure for both the benefit of the local community and national roading network while preserving a part of the history of the development of New Zealand.
This project for the NZTA involved replacing two 19th century single lane wooden bridges across the Waitaki River at Kurow, built originally as rail bridges, with two modern two lane plus walk/cycle way structures with deconstruction and removal of the old structures. Removal of the historic bridges was achieved in a manner that allowed NZTA to donate heavy Australian hardwood timbers and steel components not used in the two “display spans” on Kurow island, to the Waimate and Waitaki District Councils for reuse in other projects in the lower South Island.
This ECI (Early Contractor Involvement) project is both a tribute to NZTA, for their foresight in recognising the potential benefits that could come from this form of contract in dealing with the range of design, construction and stakeholder issues needing to be addressed, and to McConnell Dowell for ensuring those potential risks were not only dealt with, but turned into positives for all concerned through a combination of practical management and innovation. Examples of this are
- The early implementation of a partnering charter to outline the values and expectations of the project from Client, DOC, Heritage New Zealand, local councils, local Runanga and local interest groups to gain and maintain local support for the project.
- Success of this approach can be seen in the many letters and congratulatory comments from stakeholders, with the local police constable, Craig Bennett enthusing “It was an absolute pleasure to have this Company as part of this community and I know my sentiments are supported by my local community” and NZTA Highway Manager, Colin Knaggs saying “their sincere commitment to the local community and environment enhanced our performance as a project team.”
- The adoption of a composite steel/concrete bridge design using weathering steel for the first time in the South Island to produce a low maintenance structure, in keeping with the local environment , while also allowing longer spans and associated reduced work in the river over the specimen design. The reduced number of piles allowing the total length of bridge to be reduced, while maintaining hydraulic capacity
- Concrete finishing of the bridge deck to tolerances that removed the need for the normal AC levelling layer required prior to final seal.
- The use of a temporary trestle adjacent to the longer Bridge 2 to both facilitate construction of the new bridge and subsequent deconstruction of the adjacent old bridge in large enough parts to provide bridge completion ahead of schedule and deconstruction of the old bridges six months early.
In a tightly contested category the judges were also very impressed and congratulate the team on their winning entry.
Judges Peter Hay Steve Hart