Record-breaking pipe push complete!

How we pushed 4.9 km of pipeline under the Humber

We have completed the record-breaking task of installing our replacement gas pipeline within our tunnel under the Humber – taking us a major step closer to finishing our project and supplying up to 25% of Britain’s gas.

Working closely with our project partners Skanska, A.Hak and Porr, we have ‘pushed’ eight 620m long gas pipeline segments, each weighing an impressive 850 tonnes, through our tunnel – from Goxhill, North Lincolnshire to Paull, East Yorkshire.

The pipeline segments lined up at our Goxhill site ready to be pushed through the tunnel

It has been a complex process, but once complete, it will be the world’s longest hydraulically inserted gas pipeline.

So, how did we achieve this marvel of engineering?

Check out our video here.

Firstly, we flooded the tunnel with 50,000 cubic metres of treated water, enough to fill 16 Olympic swimming pools, to aid the pipeline installation. The water not only allowed the pipeline to half-float as it was pushed through the tunnel, but the high-purity of the water protects the pipeline from corrosion over the course of its lifetime.

A pipe thruster in action

Secondly, we deployed extremely powerful hydraulic thrusters, positioned behind the launch shaft of the tunnel, to push each of the pipeline segments through the tunnel at a speed of one metre per minute. As this happened each of the eight pipe strings were welded together forming a single continuous pipeline.

The next and final stages of the project will be the commissioning and connection of the pipeline to the UK’s gas network. We’re on track with the time frame set out for the project, with the next goal expected to be complete at the end of 2020.