February 2011
The Pembroke Power Station Gas Pipeline: Horizontal Directional Drilling (HDD) Crossing of Milford Haven in Wales has been shortlisted for the 2011 Ground Engineering Awards. The project submitted by Halcrow, RWE npower and LMR Drilling is shortlisted in the Geotechnical/Geoenvironmental UK Project over £1 million and Health and Safety award categories. The Ground Engineering Awards are a celebration of geotechnical and geoenvironmental achievements. They are an opportunity to recognise and reward projects that have accomplished significant results. They are also a great opportunity to bring together the industry's key players for a day of inspiration, celebration and networking.
In April 2009 RWE npower commissioned construction of a new £1000 million state-of-the-art 2000megawatts Combined Cycle Gas Turbine (CCGT) power station at Pembroke, on the south side of Milford Haven in Wales.
A key part of the enabling works associated with the CCGT was the provision of a new 450millimetres diameter gas supply pipeline, to connect the Power Station with the national gas network on the north side of Milford Haven.
The selected route option for the gas pipeline was beneath Milford Haven – a very busy commercial shipping channel - using Horizontal Directional Drilling (HDD). Halcrow commenced the feasibility study and concept design for the HDD in January 2006; and the gas pipeline was successfully installed by LMR Drilling UK in April 2010. At 3,005metres drilled length, the Pembroke Power Station Gas Pipeline: HDD Crossing of Milford Haven represents the longest HDD in Europe (the longest ever achieved globally being 3,150metres).
Whilst the £7.5million HDD works were small in comparison to the new CCGT power station, the project team were acutely aware that failure to successfully complete the gas pipeline would leave the new power station inoperable. The gas pipeline was therefore identified as a significant project risk within the context of the overall project delivery.
In addition to this significant overall project risk, the scheme was difficult from a geotechnical and engineering view point as a result of the complex hardrock geology and the depth of the Haven; which combined with the proposed length of the crossing made it a unique HDD challenge.
Despite the extreme length and challenging geology the HDD drilling works were completed within budget and programme, and with the coastline around the Haven left untouched, shipping lanes left open and with minimal disturbance to local residents. The record breaking scheme has provided a step-change in the way HDD projects can be procured, managed and delivered. Project manager for Halcrow, Guy Green said: “Successful installation of the pipeline was a great achievement for the whole team. Being shortlisted for these awards along with our client and the contractor is a great honour.”
The winner’s will be announced at a prestigious awards ceremony on the 11th May at the Grosvenor House hotel.