Wirral firm complete eight water pipe installations to a row of terraced houses in Caernarfon by drilling beneath the houses and reducing impact to gardens. The project, to install 63mm MDPE pipe to the homes in Pontllyfni near Caernarfon supplied new water main pipes to each property over a distance of around 14 meters per site.
Working in partnership with Gelli Engineering in November 2017, the Mole Team used innovative directional drilling to drill underneath the terraced houses as there was no other option to install the pipes. The project was carried out for the National Assembly for Wales who are in the process of improving utilities provision for social housing across the country.
The lead contractor, local firm Gelli Engineering, were keen to directionally drill the project to minimise impact and disruption for residents. Horizontal Directional Drilling is a method of installing pipes, cables or conduits without digging trenches. Mole Utilities have been directional drilling specialists since 1993, using dry drilling rigs that very few companies are able to use. It is used when trenching or excavating is not practical, possible, or environmentally/ economically viable.
The drills are steerable and surface launched, and can create bores of up to 250mm over a distance of up to 250 metres. Using specialist equipment, the team pilot bore a pre-determined route with any corrections or changes to be made as the drill moves through the ground. The hole is opened to the required size through an industry term called “back reaming”. The required pipe is then pulled through and connected at either end.
The ground conditions posed a number of challenges on some of the sites – recent wet weather and the rocky welsh countryside meant that the team had to work carefully and reactively, moving the drill trajectory where possible and digging out obstacles including some large boulders!
All eight drills were completed in just over two weeks and the team were able to return each of the sites to normal. The residents were pleased to have avoided the need to trench through their front gardens and are now benefitting from improved utilities service.
Mole Utilities and Gelli Engineering will continue to partner on a number of projects over the coming months to improve utilities supply for residents at sites across the region.