Skanska has been awarded a contract by National Grid to design and build a replacement high-pressure gas pipeline within a tunnel, underneath the River Humber from Paull to Goxhill, in the United Kingdom. The contract was awarded in joint venture with PORR and A.Hak for a total of £100 million ($144 million) and £39.4 million ($57 million) to Skanska. The new tunnel and pipeline will replace the existing pipeline, which lies on the riverbed.
The contract has been let, subject to planning consent for the replacement pipeline from the Planning Inspectorate, which is due in September 2016.
Over the three-year project the joint venture will provide full design and construction of the 5-km tunnel underneath the River Humber, inserting a single string of 42-in. steel pipe and connect into the above-ground installations (AGIs) at Paull and Goxhill.
Phil Croft, National Grid’s senior project manager said: “This pipeline will be the longest gas pipeline in a tunnel, inserted in a single string in the world. To do this we need partners with experience and a proven track record. Skanska, PORR and A.Hak were able to demonstrate their expertise and knowledge throughout the tender process, giving us the confidence that this was the right company to build this tunnel and pipeline in such an environmentally sensitive and commercially busy river.”
On behalf of the joint venture, Colin Nicol, Operations Director, Skanska said: “We are delighted to be awarded this contract. The joint venture was formed to bring together international expertise to deliver, in an innovative, sustainable and collaborative way, a tunnel that will protect the pipeline for the long term, helping National Grid to provide a vital service to millions of people.”
The River Humber pipeline is part of the national transmission system – connecting the import terminal at Easington, on the East Yorkshire coast, to the wider network and delivering gas to millions of customers throughout the United Kingdom.
Over time, the tidal patterns of the River Humber have eroded the river bed covering the existing pipeline, leading to parts of it being at risk of being exposed. An innovative short-term engineering solution to protect the pipeline by covering exposed areas was put in place in 2010. Because of the importance of the pipeline, National Grid is now looking to construct a new pipeline in a tunnel underneath the River Humber from the AGIs at Paull, east of Hull and south of the river at Goxhill, as a long-term replacement.
The pipeline will connect to the existing National Grid AGI sites at Paull and Goxhill and will be 3.36 miles (5.4-km) long, of which 3.18 miles (5 km) would be tunneled.
The pipeline will be 42 in. (1,050 mm) in diameter and will transport natural gas at a pressure of 70 bar.