Introduction
MV Kelly Ltd began construction on a new housing development that required the installation of a foul water pipeline. A significant challenge emerged when it was identified that the foul outfall needed to cross the A607 at Manthorpe—a busy carriageway where road closures were not permissible, ruling out the use of traditional open-cut excavation methods.
Beyond the A607, the pipeline would connect to the local Anglian Water Wastewater Treatment Works.
To overcome this challenge, MV Kelly Ltd appointed HB Tunnelling to deliver a suitable trenchless solution. Following a detailed review of the proposed depths of both the foul and storm water pipelines, as well as the ground conditions, HB Tunnelling recommended the use of guided auger boring—offering a precise and non-intrusive installation method ideal for this location.
Augerboring
Objective
HB Tunnelling carried out the trenchless installation of foul water pipelines using the guided auger boring method. The works were delivered using a Bohrtec B400 GAB rig—well-suited for drilling through a variety of soil types. Scope of Works:
- 1 no. 36 linear metre drive of DN225 clay jacking pipes, installed through stiff sandy clay.
The project presented logistical challenges, particularly due to the launch pit being located on private land, which required careful protection. Bog mats were utilised to access the works area without causing damage to the grass. Thanks to the minimal site footprint required for guided auger boring, this method proved ideal for the location.
The Challenge
In collaboration with MV Kelly, HB Tunnelling opted for a square launch pit with a built-in thrust wall to facilitate installation. A manhole box was used for the construction of the reception pit on the opposite side of the A607.
Temporary works design and pit excavation were carried out by MV Kelly, while HB Tunnelling managed the trenchless installation.
The foul pipeline was installed successfully, with no significant issues, and the works were completed within both the agreed programme and budget.
“This was another challenging project, and HB Tunnelling—who we’ve worked
with on many occasions—were, as usual, extremely helpful and efficient
throughout the design and build process. They were professional, wellorganised,
and we will certainly look to use this innovative trenchless
technology again on future schemes where appropriate.”
- MV Kelly
For more information on guided auger boring, please contact us on 0845 388 3325.
