{{Short description|Elevated roadway in west London}} {{Use British English|date=January 2016}} {{Use dmy dates|date=September 2020}} {{Infobox bridge | bridge_name = Hammersmith flyover | image = Hammersmith flyover 6523r.jpg | alt = | caption = | official_name = | other_name = | carries = {{jct|country=GBR|A|4|name1= }} | crosses = | locale = | owner = | maint = Transport for London<ref name="tfl30dec11" /> | architect = Hubert Bennett<ref name="timelines" /> | designer = G. Maunsell & Partners | engineering = | design = | material = | length = {{convert|622|m|abbr=on}}<ref name="independent" /> | width = {{convert|18.6|m|abbr=on}}<ref name="timelines">{{cite web|url=http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=1164|title=Hammersmith Flyover|publisher=Engineering timelines|accessdate=13 January 2012}}</ref> | height = | mainspan = {{convert|42.7|m|abbr=on}}<ref name="timelines" /> | spans = 16<ref name="timelines" /> | pierswater = | load = | clearance = | below = | life = | builder = J&J Dean Builders (Oscar James Dean, Malcolm James Dean & Alan Dean) | fabricator = | begin = January 1960<ref>{{cite web|url=http://www.fulhamchronicle.co.uk/fulham-and-hammersmith-news/2012/02/02/feature-the-birth-of-the-hammersmith-flyover-82029-30252806/|title=Feature: The birth of the Hammersmith Flyover|first=Rupert|last=Basham|date=2 February 2012|accessdate=2 February 2012|quote=The volume of vehicles was such an issue that during the flyover's 22-month construction period, traffic had doubled in the area, reaching a peak of 70,000 cars a day.|publisher=Hammersmith & Fulham Chronicle}}</ref> | complete = 16 November 1961<ref name="ice" /> | cost = £1,200,000<ref name="timelines" /> | open = 16 November 1961<ref name="ice" /> | inaugurated = | traffic = 85,549 (2011)<ref>{{cite web|url=http://www.dft.gov.uk/traffic-counts/cp.php?la=Hammersmith+and+Fulham#16110|title=Hammersmith and Fulham Traffic Counts: Count Point id 16110 |publisher=Department for Transport|accessdate=22 May 2013|quote=AADF for All Motor Vehicles 2011 85,549.}}</ref>{{update-inline|date=May 2024}} | preceded = | followed = | heritage = | collapsed = | closed = | replaces = | map_cue = | map_image = | map_alt = | map_text = | map_width = | coordinates = | lat = | long = | references = | extra = }}
The '''Hammersmith flyover''' is an elevated roadway in West London which carries the A4 arterial road over and to one side of the central Hammersmith gyratory system, and it links together the Cromwell Road extension (Talgarth Road) with the start of the Great West Road. It is one of the first examples of an elevated road using reinforced concrete.<ref name="ice">{{Cite journal | last1 = Rawlinson | first1 = S. R. J. | last2 = Stott | first2 = P. F. | doi = 10.1680/iicep.1962.10813 | title = The Hammersmith Flyover (Includes Plates.) | journal = ICE Proceedings | volume = 23 | issue = 4 | pages = 565 | year = 1962 }}</ref><ref name="bbc13jan">{{cite news|title=Hammersmith Flyover reopens to light traffic|url=https://www.bbc.co.uk/news/uk-england-london-16540112|date=13 January 2012|accessdate=13 January 2012|work=BBC News}}</ref>
==Design== An elevated road employing reinforced concrete balanced cantilever beam supports with a single central column. The deck spine and wings are of hollow prestressed concrete design, with each span being tensioned by longitudinal tendons (four clusters, each of sixteen {{Convert|29|mm|abbr=on|adj=on}} steel cables).<ref>[http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=1164 Engineering Timelines: Hammersmith Flyover]</ref> The flyover was designed by G. Maunsell & Partners, Consulting Engineers, led by Peter Wroth<ref>{{Cite journal | last1 = Milligan | first1 = G. | title = Charles Peter Wroth 1929–91 | doi = 10.1680/geot.1991.41.4.631 | journal = Géotechnique | volume = 41 | issue = 4 | pages = 631–635| date=December 1991 | bibcode = 1991Getq...41..631M | issn = 0016-8505}}</ref> and is {{Convert|622|m}} long.<ref name="independent">{{cite news|url=https://www.independent.co.uk/life-style/motoring/motoring-news/race-against-clock-to-fix-vital-transport-artery-for-olympics-6286998.html|title=Race against clock to fix vital transport artery for Olympics|first=Michael|last=McCarthy|date=9 January 2012|newspaper=The Independent|location=London}}</ref> When built the flyover included heating cables to "eliminate ice formation".<ref>{{cite journal|title=BICC (advert)|journal=New Scientist|page=693|date=13 December 1962|volume=16|number=317|issn=0262-4079|url=https://books.google.com/books?id=O2jajhTEkmsC&pg=PA603|accessdate=13 January 2012|last1=((Reed Business Information)) }}{{dead link |date=April 2024}}</ref> The system was initially successful,<ref>{{cite journal|journal=The Surveyor and Municipal and County Engineer|volume= 122|title=The road heating of the Hammersmith flyover has been particularly successful during this prolonged cold spell}}</ref> though a £4800 bill for the 1962–63 winter ({{Inflation|GBP|4800|1963|r=-5|fmt=eq|cursign=£}}) "so shocked Hammersmith Borough Council that, as a protest, it cut off the electricity". London County Council paid the bill after this.<ref>{{cite news|newspaper=The Economist|volume=214|issue=1|title=Snow on the Roads|page=55|quote=The bill, at £4800, for heating the Hammersmith flyover in the winter of 1962-63 so shocked Hammersmith Borough Council that, as a protest, it cut off the electricity. (The LCC now pays.)}}</ref>
The heating became defective at some point a "long time" before 2000.<ref>{{cite web|url=http://www.whatdotheyknow.com/request/hammersmith_flyover_heating_corr|title=Freedom of Information Request: Hammersmith Flyover Heating Correspondence|publisher=WhatDoTheyKnow.com|date=17 January 2012|accessdate=25 January 2012}}</ref>
==History== [[File:St Paul's Church, Hammersmith, from beneath the flyover - geograph.org.uk - 2059009.jpg|thumb|St Paul's, Hammersmith seen from under the flyover]] Completed in 1961, it was one of the first examples of its design. J&J Dean, a London-based civil engineering contractor, built the flyover at a cost of £1.2 million. The then Conservative Transport Minister Ernest Marples had been a Marples, Ridgway shareholder. To avoid a conflict of interest Marples undertook to sell his controlling shareholder interest in the company as soon as he became Minister of Transport in October 1959, although there was a purchaser's requirement that he buy back the shares after he ceased to hold office, at the price paid, should the purchaser so require.<ref>[https://api.parliament.uk/historic-hansard/commons/1960/jan/28/personal-statement#column_381 Personal Statement - The Minister of Transport (Mr. Ernest Marples)], Hansard, House of Commons, 28 January 1960</ref>
Much of the churchyard of St Paul's Church, the oldest parish church of Hammersmith, had to be cleared for the project, including an old wall and many grave markers.<ref>{{cite web|url=https://londongardenstrust.org/conservation/inventory/site-record/?ID=HAF055|title=St Paul's Churchyard and St Paul's Green|publisher=London Gardens Online|access-date=21 October 2014}}</ref>
==Repair work== thumb|Sign showing temporary flyover closure thumb|The flyover after repair work was completed in 2015, with new bolts and sections of tensile cable visible on the surface of the structure In December 2011 Transport for London (TfL) issued a statement that "damage to the ageing 1960s structure has been caused by water ingress, including salt water due to grit laid during the winter months, which has corroded and weakened the cables which help support the flyover".<ref name="tfl30dec11">{{cite press release |title=Hammersmith flyover to remain closed next week |publisher=TfL |date=30 December 2011 |url=http://www.tfl.gov.uk/corporate/media/newscentre/archive/22190.aspx |accessdate=13 January 2012 }}</ref> TfL stated there was "a very remote possibility that Hammersmith Flyover [would] collapse".<ref>{{cite news|url = https://www.bbc.co.uk/news/uk-england-london-20533457 | title = TfL report warned of Hammersmith Flyover collapse risk| publisher = BBC | date = 3 December 2012 | accessdate = 4 December 2012}}</ref><ref>{{cite web|url = http://www.whatdotheyknow.com/request/traffic_modelling_of_a4_hammersm | title = Traffic modelling of A4 Hammersmith flyover closure (Hammersmith Flyover Emergency Preparedness Plan v00e.pdf) | publisher = WhatDoTheyKnow | date = 13 April 2012 | accessdate = 4 December 2012}}</ref>
The Fulham & Hammersmith Chronicle claim that they were contacted on 14 December 2011 by a whistleblower who revealed that problems with the structure were far more severe than was being made public.<ref>{{Cite web|url=https://www.mylondon.news/all-about/fulham|title=Fulham - Latest news updates, pictures, video, reaction - MyLondon|website=www.mylondon.news}}</ref><ref>{{Cite web|url=https://londonist.com/2011/12/hammersmith-flyover-is-unsafe|title=Hammersmith Flyover 'Is Unsafe'|date=15 December 2011|website=Londonist}}</ref> The flyover was closed to all traffic from 23 December 2011<ref>{{cite news|title=Hammersmith flyover closed due to structural defect|url=https://www.bbc.co.uk/news/uk-england-london-16316283|accessdate=23 December 2011|newspaper=BBC News website|date=23 December 2011}}</ref><ref>{{cite news|title=TfL statement on the Hammersmith flyover |url=http://www.tfl.gov.uk/corporate/media/newscentre/22169.aspx|accessdate=23 December 2011|newspaper=Transport for London website|date=23 December 2011}}</ref> to 12 January 2012 after structural defects were discovered.<ref name="bbc13jan" /> From 13 January<ref name="bbc13jan" /> to 27 May<ref>{{cite news|url=https://www.bbc.co.uk/news/uk-england-london-18232270|title=Hammersmith Flyover fully opens after repairs|date=28 May 2012|work=BBC News|accessdate=28 May 2012}}</ref> the bridge was only open to a single lane of light traffic in each direction for repair work. TfL planned to strengthen six of the sixteen arches before the London 2012 Olympic Games and the remaining ten arches after the games.<ref>{{cite press release|url=http://www.tfl.gov.uk/corporate/media/newscentre/22288.aspx|title=Hammersmith flyover to reopen for cars and light traffic as vital repair works continue|date=11 January 2012|accessdate=13 January 2012|publisher=TfL}}</ref> New post-tensioned steel cables "are being installed in concrete blocks above and below the deck's central reservation".<ref>{{cite web|url=http://www.nce.co.uk/news/structures/hammersmith-flyover-cable-replacement-starts-this-week/8626208.article|title=Hammersmith flyover cable replacement starts this week|date=9 February 2012|first=Declan|last=Lynch|publisher=New Civil Engineer|accessdate=13 February 2012}}</ref> The repairs are now complete and extended the life of the bridge by 15 years.<ref name="tunnel" /> The cost of repairs was estimated to be around £10 million.<ref>{{cite web|url=http://www.nce.co.uk/features/structures/hammersmith-flyover-returning-to-full-strength/8626884.article|title=Hammersmith flyover: returning to full strength|date=23 February 2012|first=Declan|last=Lynch|publisher=New Civil Engineer|accessdate=25 February 2012}}</ref>
In June 2013 it was announced further repairs were required, a project estimated to cost £60m.<ref>{{cite news|url=https://www.standard.co.uk/news/transport/hammersmith-flyover-needs-60m-repair-job-after-10m-emergency-work-two-years-ago-8656785.html|first=Jonathan|last=Prynn|date=13 June 2013|newspaper=London Evening Standard|title=Hammersmith flyover needs £60m repair job after £10m emergency work two years ago|accessdate=13 June 2013}}</ref>
Transport for London announced that "The 18-month project will see the flyover strengthened, the bearings underneath the structure replaced, a new carriageway drainage system [fitted] and the entire flyover waterproofed and resurfaced."<ref>{{cite web|url=http://www.tfl.gov.uk/corporate/projectsandschemes/28466.aspx|date=22 October 2013|publisher=Transport for London|title=Hammersmith flyover strengthening and refurbishment|accessdate=22 October 2013}}</ref> The cost subsequently rose to £100 million.<ref>{{Cite web|url=https://www.newcivilengineer.com/archive/hammersmith-flyover-strengthening-stressful-work-23-02-2015/|title=Hammersmith Flyover strengthening: Stressful work|date=23 February 2015|access-date=January 12, 2023}}</ref> TfL announced on 4 September 2015 that repair work to the flyover had been completed.<ref>{{Cite web |date=2015-09-04 |title=£100m refurbishment of Hammersmith Flyover completed |url=https://tfl.gov.uk/info-for/media/press-releases/2015/september/-100m-refurbishment-of-hammersmith-flyover-completed |access-date=2023-01-31 |publisher=Transport for London |language=en-GB}}</ref>
==Replacement tunnel== The construction sector has proposed that the flyover be replaced with a tunnel. A group of architects, including Assael Architecture and Simone de Gale, ran an event as part of London Festival of Architecture in 2012 to introduce the idea and gauge public interest.<ref>{{cite web |url=http://www.lfa2012.org/events/view/flyover-makeover-help-plan-the-hammersmith-flyunder-283 |title=FLYOVER MAKEOVER: Help plan the Hammersmith Flyunder! {{pipe}} London Festival of Architecture |access-date=2013-11-14 |url-status=usurped |archive-url=https://web.archive.org/web/20131202222129/http://www.lfa2012.org/events/view/flyover-makeover-help-plan-the-hammersmith-flyunder-283 |archive-date=2 December 2013}}</ref> Following a mixed but mostly positive response, the West London Link<ref>{{cite web| url = http://www.westlondonlink.com| title = West London Link : A Tunnel to replace Hammersmith Flyover}} </ref> was set up to explore the options in more detail. Three options were presented to the public in February 2014.<ref>{{cite web |url=http://www.lbhf.gov.uk/Directory/News/hammersmith_flyunder.asp |title=Hammersmith flyunder - Hammersmith & Fulham |access-date=2014-02-25 |url-status=dead |archive-url=https://web.archive.org/web/20140301081831/http://www.lbhf.gov.uk/Directory/News/hammersmith_flyunder.asp |archive-date=1 March 2014}}</ref> A template is the Alaskan Way Viaduct replacement tunnel in Seattle. The then mayor of London, Boris Johnson, added publicity to the concept.<ref name="tunnel">{{cite news|url=https://www.standard.co.uk/news/mayor/hammersmith-flyover-the-solution-could-be-to-dig-a-tunnel-says-boris-7311826.html|title=Hammersmith flyover? The solution could be to dig a tunnel, says Boris|first=Peter|last=Dominiczak|date=26 January 2012|access-date=26 January 2012|newspaper=London Evening Standard|url-status=live|archive-url=https://web.archive.org/web/20120128234113/http://www.thisislondon.co.uk/standard-mayor/article-24031088-hammersmith-flyover-the-solution-could-be-to-dig-a-tunnel-says-boris.do|archive-date=28 January 2012}}</ref> In February 2015 Johnson suggested a toll charge might be needed to cover the estimated £1.5 billion cost of building the tunnel.<ref>{{Cite web|url=https://www.standard.co.uk/news/london/hammersmith-flyover-tunnel-new-road-toll-replacement-boris-johnson-a2-10033139.html|title=Drivers will have to pay toll for tunnel that could replace|first=Pippa|last=Crerar|date=9 February 2015|website=Evening Standard|access-date=January 12, 2023}}</ref>
== See also == *List of bridges in London
==References== {{Reflist}}
{{coord|51|29|28|N|00|13|39|W|region:GB-HMF_type:landmark|display=title}}
Category:Bridges in London Category:Road junctions in London Category:Streets in the London Borough of Hammersmith and Fulham Category:Elevated overpasses in London Category:Hammersmith Category:A4 road (England)