New pictures show huge tunnel under River Humber
Work is half way to completion
By Hull Daily Mail | Posted: 11 Jan 2019
New pictures have emerged showing the amazing progress made by a tunnel boring machine which is currently halfway through drilling underneath the River Humber.
The remarkable snap showed just how far "Mary" - the name of the 510-tonne, 160m-long machine - has achieved following the start of the £100m project in April last year which will see a 5km tunnel house a new gas pipeline.
National Grid say it has taken 200,000 man hours so far, with a total of 2,023 concrete rings, each consisting of six segments, constructed behind the machine as she tunnels 35 metres below the bed of the river from Goxhill to Paull.
It is believed that the work, which will secure 20 per cent of Britain's gas supplies, is to be completed by the end of Spring.
Steve Ellison, project manager said: "Mary has done a brilliant job to date and we and our contractors are delighted to have reached the halfway point on the tunnel.
"There is still a lot more work to, do but I would like to say a big thank-you to the 40-strong team of engineers who have worked around the clock in very challenging conditions to get us to this important milestone.
“The machine has pretty much been operating 24 hours a day with the odd shut-down for repair or maintenance since the tunnelling work started on 6 April 2018. There are 20 engineers manning her on every shift and they work in very cramped and warm conditions, far below the river bed.
“All the engineers working on Mary have to undergo specialist training. There is only one emergency exit from the machine and that is back along the tunnel, which will be nearly a 5km journey once she gets towards the opposite bank of the river.
"As you would expect, safety is our prime concern. All plant has a fire suppressant system, conditions in the tunnel are monitored along its entire length and we have regular emergency exercises and employ an on-site emergency team."
Once the tunnel is completed, Mary will be removed from the tunnel via a shaft on the opposite bank of the river at Paull and a new 42" diameter gas pipeline will be laid inside the tunnel.
This will replace the existing gas pipeline which currently crosses the river and is laid in a trench just below the river bed.
This pipe at risk of being exposed by shifting tides. Work has been carried out to keep it buried but the Humber Pipeline Replacement project offers a long-term solution.
National Grid was awarded the £100m contract to build the tunnel to a joint venture made up of Skanska, PORR Bau GmbH and A. Hak.
The giant machine was built in Badem-Wurttemberg in Germany and was shipped via Holland to Immingham Docks.
It was then transported by road along the A160, A180 and A15 in December, ready for assembly at the site in Goxhill.