Hurlstone Earthmoving Ltd

In November 2004, Hurlstones commenced operations at Highbrook, as head contractor, for Highbrook Development Limited. The development is one of the largest industrial sub-divisions ever under-taken in New Zealand. The bulk earthworks alone involved over 1,400,000 m3 of "cut-to-fill" and 200,000 m3 of unsuitable material. The contract value is $54,000,000 over the 3 project stages completed from 2004 to 2009.

The project was managed collaboratively, in partnership with a number of parties and in particular the client - contractor relationship. Open communication encouraged best practice and an open exchange of ideas. The project required a high level of management with a number of contracts being carried out at the simultaneously and often within confined areas, including a number of different building contracts and major power installations.

There were a number of technical complexities to the job including managing the unstabilised area for the project as per ARC requirements when faced with over optimum water content material requiring conditioning and subsequent substantial drying beds and a fast tracked programme requiring areas to be opened and closed within tight time frames.

The earthworks required a large cut-to-fill operation where the soils encountered were extremely sensitive and characterized by an over optimum water content. In addition, substantial layers of peat were found in areas which required additional management, including experimentation of material ratios to meet compaction requirements. The peat layers also created further challenges to the roading works programme throughout winter which threatened building deadlines. There were also substantial quantities of unsuitable material which were recycled and spread around the foreshore reserve areas and mixed into fill areas. The clients very high standards meant very strict quality control systems were necessary throughout the project.

The projects location adjacent to the sensitive environment of the Tamaki Estuary required strict environmental compliance. The erosion and sediment control systems were constructed to an extremely high standard ensuring they were durable for the entire length of the project. Some of the ponds were required to last for 4 years. A very high level of maintenance was carried out on the systems and helped by the strong environmental culture that was created on-site where the workers on-site were constant inspectors informing management of any issues. A consultative and collaborative relationship was also formed with the Auckland Regional Council and as a testament to our excellence of sediment control management diligence in maintenance and the high quality and durability of our controls over the summer periods, we received significant winter work consents over the 2005, 2006, 2007, 2008 and 2009 winter periods. A number of environmental initiatives were carried out on-site including experimentation with flocculant gel and silt socks on-site to great success.


Website: http://www.highbrook.co.nz