Dunstans Construction Group was awarded HDD works for the Victorian Northern Interconnector Expansion (VNIE) Project. In 2016, as part of Separable Portion 1, the installation of a 400mm steel pipeline beneath the Goulburn River was delivered utilising the largest Herrenknecht Horizontal Drill Rigs in Australia.
- Dunstans successfully completed the 630m crossing of the Goulburn River, with installation of Powercrete Coated Steel Pipe, for the duplication of sections of the existing gas pipeline that runs from Wollert to the North of Melbourne to Young in NSW.
- Utilising a German built, Herrenknecht 400 tonne directional drill enabled superior trenchless technology to be employed rather than the ‘open-cut’ methodology used in the 1970’s for the original installation.
- The geology encountered was predominately a quartz stone, with upper layers incorporating gravel, shale and soft alluvia’s of the low lying river flats of the surrounding farm lands.
- Working in both a cultural heritage and environmentally sensitive area, our team successfully delivered the works with minimal impact. This included the installation of a drill fluid return line that was sunk to the bottom of the Goulburn River with an anchoring system. This allowed for full access to the River for unimpeded recreational use during the installation.
- In partnership with the client, Dunstans’ liaised with neighboring stakeholders to mitigate the impact of the HDD works. Noise monitoring assessments were conducted prior to commencement and during operation to ensure minimal disruption to the operations of the adjacent prized horse stud and poultry farm.
Despite the challenging location amid sensitive farming areas and environmental and cultural heritage zones, installation of the gas line was successfully delivered during some of the wettest months ever recorded in Victoria. The injury free project was completed with Dunstans’ methodology maintaining the pipes coating integrity in spite of the harsh geology of the quartz formation and riverbed gravels.