Editing Humber Bridge (section)

===Construction===
The main contractor for the steel superstructure was British Bridge Builders (the same grouping as for the Forth and Severn Road Bridges comprising Sir William Arrol & Co., then a unit of NEI Cranes Ltd, [[Cleveland Bridge & Engineering Company]], and [[Dorman Long|Redpath Dorman Long Ltd]]).<ref>{{cite news |title=Cleveland Bridge wins major contract to refurbish Humber Bridge |url=https://www.gazettelive.co.uk/business/business-news/cleveland-bridge-wins-major-contract-15960933 |newspaper=Gazette Live |date=12 March 2019 |access-date=18 September 2021}}</ref> The contractor for the concrete towers, anchorages and sub-structure was [[John Howard (civil engineer)|John Howard & Co Ltd]] of [[Chatham, Kent]], which was later bought by [[Amec Foster Wheeler|Amec]].<ref>"Bridging the Humber" {{ISBN|0 9501098 6 X}} {{Full citation needed|date=May 2014}}{{page needed|date=May 2014}}</ref> Concrete was chosen for the towers, instead of steel, partly due to cost, but also to suit the landscape.<ref name=":0" />

Work began on the southern approach road in July 1972 by [[Clugston Group|Clugston Construction]] of Scunthorpe. The {{cvt|2.5|km|mi}} approach road to the A1077 junction, by [[Costain Group|Costain]] Civil Engineering, began in September 1976. It included a {{cvt|320|m|yd}} span from the southern anchorage of seven pre-stressed concrete box sections and the A1077 junction, costing £4.25&nbsp;million. Work on the bridge substructure (foundations) began in March 1973. To reduce heat of [[Hydration reaction|hydration]] in the concrete, which produces [[calcium silicate hydrate]] from [[belite]], as much as 60 per cent of the [[Portland cement]] was replaced with [[ground granulated blast-furnace slag]] (GGBS). It took longer to build the southern anchorage due to a [[Slurry wall|diaphragm wall]] design due to there not being enough shallow bedrock. The main southern approach roads from Barton to the [[M180 motorway]] junction at [[Barnetby]] were built in the late 1970s by Clugston Construction of Scunthorpe, opening in 1978.<ref>{{cite web |title=Bonby, North Lincolnshire – Problem with your input |url=http://www.bonby.org/photos/photo?photo_id=412692 |url-status=dead |publisher=bonby.org |archive-url=https://web.archive.org/web/20151007061758/http://www.bonby.org/photos/photo?photo_id=412692 |archive-date=7 October 2015}}</ref>

The towers were constructed by [[slipforming]] and the north tower was completed by May 1974. The southern foundations were completed in September 1975, with the pier completed in March 1976, and the southern tower was completed by September 1976; the bridge had been planned to open in 1976. The northern tower and anchorage was built on solid chalk but the southern tower and anchorage were built on fissured [[Kimmeridge Clay]], {{cvt|500|m|yd}} from the southern shore and built with a difficult [[Caisson (engineering)|caisson]] design. The subcontractor for the concrete was Tileman & Co. of [[Shipston-on-Stour]], south [[Warwickshire]].

Cable spinning took place between September 1977 and July 1979. Each cable weighs {{cvt|5500|t|LT}}, with 37 strands of 404 lengths of cable. The cable on the northern span has four extra strands. Each cable can take a load of {{cvt|19400|t|LT}}. The deck is of [[box girder]] form, the box sections around {{cvt|140|t|LT}} each. The first box sections were assembled in June 1975 and put into the main span on 9 November 1979. The toll buildings and north approach road were built by A.&nbsp;F. Budge of [[Retford]], Nottinghamshire, costing £2.9&nbsp;million. Work began on the administration building in November 1976. The toll system was manufactured by [[Siemens Plessey|Plessey Controls]] of [[Poole]], Dorset. Corrosion resistance on the steelwork was provided by Camrex Corrosion of [[Bellshill]], [[North Lanarkshire]]. The road was laid by [[Tarmac Group|Tarmac Roadstone]] of Wolverhampton with [[Asphalt concrete|mastic asphalt]].<ref>{{cite journal |title=Machine layed mastic asphalt for Humber Bridge |format=PDF |url=http://www.ciht.org.uk/download.cfm/docid/561403E9-8292-4B16-8C4590E9D97D10E4 |journal=The Highway Engineer |date=July 1981 |archive-url=https://web.archive.org/web/20151006225703/http://www.ciht.org.uk/download.cfm/docid/561403E9-8292-4B16-8C4590E9D97D10E4 |archive-date=6 October 2015}}</ref> In 2017, the bridge was designated a [[listed building|Grade I listed building]].<ref name=BBC40626412>{{cite news |url=https://www.bbc.co.uk/news/av/uk-40626412/humber-bridge-given-grade-i-listed-status |title=Humber Bridge given Grade I listed status |website=BBC News |date=17 July 2017 |access-date=17 July 2017}}</ref><ref>{{NHLE |num=1447321 |desc=The Humber Bridge |access-date=9 January 2019}}</ref>