Grafton Gully Bridge

This bridge was designed to be an aesthetically interesting centrepiece to the cycleway project through Grafton Gully. Spanning a 20m gully with a 4m North-South fall, the bridge was developed as an ‘S’ Bend design with constant fall of 10 degrees. Design considerations included craneage weight, fabrication methodology, constant fall and precast deck mould design.

The main beam was fully fabricated from CNC cut 16 & 20mm plate. Sections were fabricated and pre-assembled in our workshop, metal arc zinc spray and vinyl coated at Counties Industrial Coatings in Pukekohe and assembled on site in situ.

Access for craneage was particularly tight for the 300T road crane and great care was taken to maintain safe lifting capacity and radius within section size and weight. Particular care was required to avoid damage to any trees on site, the crane was located against the drip line of a protected oak.

This project won the 2015 Steel Construction NZ "Excellence in steel construction" award for projects under $500,000.