The Humber tunnel project will be built by a JV of Sweden’s Skanska, Austrian building contractor PORR and Dutch pipeline firm A.Hak.
The contract is to design and build a replacement high-pressure gas pipeline within a tunnel, underneath the River Humber from Paull to Goxhill, replacing the existing pipeline that lies on the riverbed.
Costain was named programme manager last month, as previously reported.
The construction contract has been let, subject to planning consent for the replacement pipeline from the Planning Inspectorate, which is expected in September 2016.
Over the three-year project, the joint venture will provide full design and construction of the 5km tunnel underneath the river Humber, inserting a single string of 42-inch diameter steel pipe and connect into the above-ground installations (AGIs) at Paull and Goxhill.
National Grid senior project manager Phil Croft 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.”
Skanska operations director Colin Nicol 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 terminal at Easingtonto the wider network. 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 short-term engineering solution to protect the pipeline by covering exposed areas was put in place in 2010 but National Grid now needs a long-term replacement.