National Grid’s new 160m long, 510 tonne tunnelling machine has been christened Mary, after Mary Fergusson, the first female fellow of the Institute of Civil Engineers.
The name was chosen by Kasey Doney, eight, a pupil at Paull Primary School near Hull, who is pictured with a section of the machine on the site where tunnelling will start, at Goxhill on the south bank of the River Humber.
The tunnelling machine has now been assembled on site and, in the next few weeks, will begin a five kilometre, year-long journey under the river to emerge on the north bank at Paull. It will create a 3.65 metre diameter tunnel as it travels, around 35 metres below the river bed.
Once the tunnel is finished, a new 42 inch diameter gas pipeline will be laid inside it to replace an existing one. The gas pipeline which currently crosses the river is laid in a trench just below the river bed but is 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 has awarded the £100m contract to build the tunnel to a joint venture made up of Skanska, PORR Bau GmbH and A. Hak.