Wilson Contractors recently undertook a technically demanding project in Invercargill, demonstrating their expertise and innovation in civil engineering. The project involved replacing two earthenware foul sewer mains located approximately 3 metres deep, intersecting Wachner Place—a bustling pedestrian and main road within the Invercargill CBD.

Project Overview

The primary challenge was to upgrade the existing sewer lines without disrupting the services. We decided the best solution was pipe cracking. This method involved using a horizontal drill fitted with steel rods to create a new cavity by bursting the existing pipe and simultaneously installing a new one along the same alignment. This approach was particularly suited for the dense urban environment, reducing the need for extensive excavation.

Technical Skills and Challenges

Our key challenges included navigating the existing infrastructure, such as the main communication lines for Invercargill, and the Wachner Place clock tower. The team worked hard to complete the project within the seven week deadline.

Innovative Solutions 

We devised several innovative solutions to overcome these challenges:

Specialised Equipment:  A task-specific reaming head was sourced to grind the existing pipe into small pieces, creating a clear cavity for the new pipe.

Minimised Disruption: Great logistical planning and the use of the horizontal drill  ensured that traffic flow was maintained, with minimal disruption to pedestrians and vehicles. Public areas were fenced and screened effectively.

Project Outcome

The project was a resounding success. The chosen method and equipment proved highly effective, maintaining service continuity and minimising impact on the surrounding area. We were not only able to met but exceeded the project deadlines, highlighting our teams capability to handle complex and high-stakes projects.

This project allowed us to demonstrate our technical expertise and innovative approach, as well as being a project that we can use as an example to showcase what our horizontal drill is capable of. The successful completion of this project underscores our ability to tackle challenging projects efficiently, ensuring minimal disruption to the public and maintaining high standards of service continuity. As we look forward to future projects, this achievement serves as a benchmark and a source of pride for our team.