Dynapac

The Hungerford road in Houghton bay, New Zealand, is well-known for its steepness. The 700-metre street rises sharply from Queens Drive on the south coast up to View Road and then plunges down to Houghton Bay Road.

Challenges of paving on steep hills

Due for resurfacing, many contractors were put off by the steepness of the hill to undertake this task. As one of the steepest roads in Wellington, this job requires machines that can climb on hills to lay asphalt at a slope angle of 16, 18 and 22 degrees.

Asphalt is a mixture of aggregate and bitumen that creates a durable and weather-resistant surface material with a good grip. It is usually ideal for steep driveways of up to around a 10-degree gradient.  However, it can be challenging to lay and compact on very inclined roads. Because of the steepness of Hungerford road, achieving the optimal, uniform smoothness was more difficult than usual.

Paving on Hungerford Road

KRN Surfacing Ltd, the first company to bring Dynapac pavers to New Zealand, was commissioned to handle this resurfacing project.  

Work began mid-April 2021, even with the tough challenge of pulling off the incline, KRN Surfacing was able to complete the entire project in just a week. Other than having the best and capable crew to handle the project, superior machines were also required to overcome paving and compaction on the hill. The Dynapac machines involved in this paving project were the large tracked paver Dynapac SD2500CS and the Dynapac combi roller.

To achieve the best paving quality, you need to rely on a high-performance screed, smooth material flow and an efficient, powerful drive. Dynapac pavers come with advanced functions to help the operators achieve desired results in complicated applications. The screed load-and unload system provides support to maintain the desired paving level. For example, the unload function can be useful when using soft paving materials as it transfers some of the screed weight to the tractor, preventing the screed from sinking into the material. The load function uses the screed lifting cylinders to transfer weight from the tractor to the screed; this avoids bumps appearing on the surface when starting with colder material after a stop.

“Dynapac paver is absolutely phenomenal. It is definitely a league above the others! We were all very surprised that the Dynapac paver could handle the steep hill with no problems,” said Robert Storey, Director at KRN Road Surfacing Ltd.

The mill and pave work was completed on 23 April 2021, to the satisfaction and approval of all stakeholders.