M50 HDD Crossing, Cherrywood, Dublin

Dún Laoghaire gas network pipeline drilling contractors
Project brief

Cherrywood is a new mixed-use development of residential and retailing situated to the southeast of Dublin city in Dún Laoghaire–Rathdown. Balfour Beatty CLG, working on behalf of Gas Networks Ireland (GNI) commissioned Peter McCormack and Sons to undertake the installation of a new 450mm steel carrier pipe crossing of the M50 motorway by means of horizontal directional drilling (HDD) which will service the new development. Peter McCormack and Sons Ltd also completed the insertion of the 315mm PE gas main into the 450mm steel carrier pipe post installation with two 5m deep connection shafts constructed either side of the HDD to receive and connect onto the 315mm PE gas pipe.

Award winning project

The success of the HDD and associated works was reflected by the fact that Balfour Beatty CLG won project of the year for the overall scheme at the Plant & Civil Engineer Construction, Quarry & Recycling Awards 2019. The collaborative approach taken by all partners ensured that this project was delivered safely and ahead of programme for the Client. The Cherrywood project further demonstrates Peter McCormack & Sons diverse skill set of not only successfully completing complex HDD’s, but also delivering the associated utility and civil engineering elements.

Project Information
  • Utility: Gas
  • Length: 250 metres
  • Depth: 7 metres
  • Pipe: 1 x 450mm steel carrier pipe to carry a 315mm PE gas main
  • Geology: Granite & Boulder Clay
  • Geology
  • Works
Understanding Geology

As always geology has a major role in any HDD project, at the M50 crossing the ground along the HDD section consisted of boulder clay (till) on north side of the M50 transitioning to a fine to coarse grained granite to the south-side. This change in strata was of concern but was ultimately overcome by the correct selection of tooling, fluid design and management.

Site works

Our site team also completed 340m of open-cut pipe laying, welding and preparation of the 315mm PE gas pipe as part of the civils work package which included the delicate crossing of a 33” Victorian era water main.