Humber Gas Tunnel

In 2009, underwater surveys revealed that the pipeline carrying natural gas between Easington and the south side of the Humber Estuary was at risk of being damaged. The Humber Estuary is the fourth-largest estuary in Great Britain, and the third busiest in terms of shipping. The former pipeline, which was constructed in 1984, was trench-laid on the floor of the estuary, and whilst it was still safe, it was listed on National Grid's "Vulnerable Infrastructure Register", as it was prone to tidal erosion and "third-party impact, both of which could result in catastrophic failure of the pipeline."{{sfn|Chambers|2018|p=1}}{{sfn|HGPRP|2018|p=6}}{{cite news |last1=Casci |first1=Mark |title=Work to complete the world's largest hydraulically inserted gas pipe completes under Humber Estuary |url=https://www.yorkshirepost.co.uk/business/work-build-5-kilometre-gas-pipeline-underneath-humber-completes-creating-worlds-largest-hydraulically-inserted-gas-pipeline-2913159 |access-date=15 December 2020 |work=The Yorkshire Post |date=14 July 2020}} Although remedial work was undertaken in 2010 and 2012, because the pipeline feeds up to 20% of gas into the National Transmission System (NTS), a replacement project was devised to enable security of supply.{{sfn|HGPRP|2018|pp=3–4}} The River Humber Gas Pipeline Replacement Order 2016, was approved in 2016, which gave authority for the National Grid to build a replacement pipe and all ancillary works.{{cite web |title=The River Humber Gas Pipeline Replacement Order 2016 |url=https://www.legislation.gov.uk/uksi/2016/853/schedules/made?view=plain |website=legislation.gov.uk |access-date=15 December 2020}}

The new pipeline would be buried underneath the river in a specially constructed tunnel, and would run parallel to the old pipeline from Paull in the north east to Goxhill in the south west.{{sfn|HGPRP|2018|p=3}} This would then connect to the existing pipeline to Hatton compressor station in Lincolnshire, which in turn supplies gas to the south of England.{{sfn|HGPRP|2018|p=7}} A {{convert|160|m|adj=on}} tunnel boring machine (TBM), christened Mary,{{#tag:ref|The TBM is named after Mary Fergusson, the first female president of the Institution of Civil Engineers (ICE).|name=Mary|group=note}} started running north eastwards from Goxhill in Lincolnshire in April 2018. The TBM reached Paull in the East Riding of Yorkshire, 18 months later.{{cite news |last1=Winter |first1=Phil |title=There is now a 5km tunnel running under the River Humber |url=https://www.hulldailymail.co.uk/news/hull-east-yorkshire-news/tunnel-under-river-humber-now-3311700 |access-date=15 December 2020 |work=Hull Live |date=12 September 2019}} The TBM had a diameter of {{convert|4.38|m}}, which allowed for the concrete casing to be inserted on the walls of the new tunnel which consisted of rhomboidal and trapezoidal precast concrete segments {{convert|225|mm}} thick, and {{convert|1.2|m}} in length.{{sfn|Assenmacher|2018|p=1}} The chalk slurry dug from the chalk beds underneath the Humber was treated and used to remediate a former chalk quarry at Goxhill.{{cite news |title=Humber estuary gas tunnel drilling work finishes |url=https://www.bbc.co.uk/news/uk-england-humber-49691773 |access-date=15 December 2020 |work=BBC News |date=13 September 2019}} The material excavated as part of the tunnelling process was mostly chalk, having dug through the Burnham Chalk and Flamborough Chalk Formations, but with glacial deposits at the north bank near Paull. The pipe is horizontal below the estuary, but the down gradients at each portal are at an incline of 4% for {{convert|450|m}} at Paull, and {{convert|650|m}} at Goxhill.{{sfn|Assenmacher|2018|p=2}}

The pipe was then fitted out and flushed with {{convert|50e3|m3}} of pure water to make it ready to receive the new pipeline.{{cite news |last1=Laister |first1=David |title=Record-breaking under Humber gas pipeline installation completes |url=https://www.business-live.co.uk/economic-development/under-humber-gas-pipeline-installation-18595548 |access-date=15 December 2020 |work=Business Live |date=14 July 2020}} On 23 June 2020, the first section was pushed into the tunnel and this continued until 9 July 2020.{{cite news |last1=Morby |first1=Aaron |title=World record engineering feat for Humber gas pipeline – video |url=https://www.constructionenquirer.com/2020/07/16/world-record-engineering-feat-for-humber-gas-pipeline-job/ |access-date=15 December 2020 |work=Construction Enquirer News |date=16 July 2020}} The pipes were delivered in shorter sections, and then welded out of the tunnel into {{convert|600|m|adj=on}}+ sections.{{sfn|Assenmacher|2018|p=1}} Two hydraulic thrust machines inserted the pipes at a rate of {{convert|1|m/s}} into the tunnel, so that the pipe moved into the tunnel, suspended in the water.{{sfn|Assenmacher|2018|p=1}}{{cite news |last1=Hancock |first1=Michaila |title=Record breaking pipeline insertion for River Humber gas project |url=https://www.newcivilengineer.com/latest/record-breaking-pipeline-insertion-for-river-humber-gas-project-17-07-2020/ |access-date=15 December 2020 |work=New Civil Engineer |date=16 July 2020}} Rollers were used to move the pipes into the tunnel, and each section end was welded to the start of the new {{convert|620|m|adj=on}} pipe section. The pipe has been designed to last 40 years, whilst the tunnel has been lifed at 120 years.{{cite news |last1=Waller |first1=Jamie |title=5km long gas pipeline beneath the River Humber enters record books |url=https://www.grimsbytelegraph.co.uk/news/local-news/5km-long-gas-pipeline-beneath-4682735 |access-date=15 December 2020 |work=Grimsby Live |date=9 November 2020}} All works above ground will be returned to agricultural use, and aside from the Above Ground Installations (AGIs) at Paull and Goxhill, no evidence of the pipeline or tunnel will be visible on the surface.{{cite book |last1=Jukes |first1=S |title=Tunnels and underground cities : engineering and innovation meet archaeology, architecture and art. Volume 7, Long and deep tunnels |date=2020 |publisher=Taylor & Francis |location=London |isbn=978-0-367-46872-9 |page=3,893 |chapter=The Feeder 9, River Humber Replacement Pipeline Project, United Kingdom}}

The pipeline was commissioned and gas started flowing through for the first time in December 2020. It is designed to carry up to 20% of the United Kingdom's gas supply, during peak winter demand. The pipe is the longest pipeline in a tunnel in Europe and is also the longest hydraulically inserted gas pipeline in the world, for which it was awarded a Guinness World Record in November 2020.{{cite news |editor-last=Mitchinson|editor-first=James|title=Gas pipe under the Humber is a record breaker |work=The Yorkshire Post |date=15 December 2020 |page=10|issn=0963-1496}}{{sfn|HGPRP|2018|p=4}}{{cite news |title=[9 November] River Humber gas pipeline – officially world record breaking|url=https://www.nationalgrid.com/9-november-river-humber-gas-pipeline-officially-world-record-breaking |access-date=15 December 2020 |work=The National Grid |date=9 November 2020}} The project was costed at around the £100 million mark in 2016, but on opening, full works, remediation and the installation of the AGIs (above ground installations), meant the cost was £150 million. Initially, Ofgem refused National Grid the authority to pass the cost of the project onto consumers, with Ofgem citing that there was no need to carry out the work, "despite National Grid’s claim that the 3km-long pipeline was at risk of catastrophic failure." By this point in August 2018, National Grid had already spent £90 million on the then estimated £140 million project. Ofgem responded by saying that "National Grid has not demonstrated that the benefits of replacing the pipe outweigh the costs".{{cite news |last1=Gosden |first1=Emily |title=Humber pipe 'catastrophe' warning falls on deaf ears |work=The Times |issue=((72,623)) |date=9 August 2018 |page=36|issn=0140-0460}} However, in September 2018, Ofgem changed their view and allowed the National Grid to charge £111 million of the cost to consumers. Initially, National Grid had asked for £140 million, but Ofgem argued that "...the project could have been delivered more efficiently."{{cite news |title=A £111m cost to consumers of new Humber gas pipeline |url=https://www.yorkshirepost.co.uk/news/aps111m-cost-consumers-new-humber-gas-pipeline-249191 |access-date=15 December 2020 |work=The Yorkshire Post |date=28 September 2018}}

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• Length (of tunnel) – {{convert|4,860|m}}
• Diameter of TBM – {{convert|4.38|m}}
• Diameter of concrete tunnel – {{convert|3.65|m|0}}
• Average depth – {{convert|30|m}}{{cite news |last1=Vaisanen |first1=Ida |title=Key gas pipeline tunnel has been completed in Humber |url=https://www.theicon.org.uk/key-gas-pipeline-tunnel-has-been-completed-in-humber/ |access-date=15 December 2020 |work=The Icon |date=25 January 2020}}
• Length of pipes (x 8) – {{convert|620|m}}
• Diameter of pipes – {{convert|1.05|m}}{{cite news |title=Drilling work starts on £100m River Humber gas tunnel |url=https://www.bbc.co.uk/news/uk-england-humber-43697444 |access-date=15 December 2020 |work=BBC News |date=9 April 2018}}
• Weight of individual pipe sections – {{convert|850|tonne}}
• Gas delivery capacity of pipeline – {{convert|70e6|-|100e6|m3}} per day.{{#tag:ref|This represents 20% of the UK peak winter demand for gas.|name=Gas demand|group=note}}

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• Easington Gas Terminal
• National Transmission System

{{reflist|group="note"}}

{{reflist}}

• {{cite journal|last=Assenmacher|first=Stephen|title=Humber Crossing – Feeder 9 Replacement New gas pipeline underneath the River Humber in England

|journal=World of PORR|date=2018|issue=172|publisher=A. Porr Aktiengesellschaft|location=Wien|oclc=838805107}}

• {{cite report|last=Chambers|first=Paul|title=Humber Pipeline Tunnel Launch Pit|website=britishtunnelling.org.uk|format=PDF|access-date=15 December 2020|date=January 2018|url=https://www.britishtunnelling.org.uk/ajax/functiongrabber.asp?loadfunction=downloadfile&f=downloads&filename=2018+Harding+Prize+RU+Humber+Launch+Pit+P+Chambers+Revision+2%2Epdf}}
• {{cite report|title=River Humber Gas Pipeline Replacement Project (Feeder 9)|date=May 2018|publisher=National Grid|website=ofgem.gov.uk|format=PDF|url=https://www.ofgem.gov.uk/ofgem-publications/133328|access-date=15 December 2020|ref={{harvid|HGPRP|2018}} }}

• [https://www.nationalgrid.com/uk/gas-transmission/land-and-assets/river-humber-pipeline-replacement/resource-centre National Grid Resource Centre]
• [https://infrastructure.planninginspectorate.gov.uk/projects/yorkshire-and-the-humber/river-humber-gas-pipeline-replacement-project/?ipcsection=docs Planning documentation]

{{Tunnels in Yorkshire}}

Category:2020 establishments in England

Category:Economy of the East Riding of Yorkshire

Category:Energy infrastructure completed in 2020

Category:Natural gas pipelines in the United Kingdom

Category:Tunnels in the East Riding of Yorkshire