Tinsley Viaduct#Tinsley cooling towers

File:Tinsley Viaduct 28-04-06.jpg

The lower deck of the viaduct was opened in March 1968{{cite web|url=http://www.irsociety.co.uk/Archives/23/Tinsley.htm|title=Tinsley Viaduct, Sheffield|first=Sydney A.|last=Leleux|date=February 1969|access-date=16 November 2006}} and the upper deck, carrying the M1, on 19 October 1968.{{cite news | title = Superway | newspaper = The Guardian | pages = 12 | date = 21 October 1968 | url = https://www.newspapers.com/image/259907781/ | access-date = 27 January 2019}}{{subscription required|via=newspapers.com|quote=The 35-mile Aston-Sheffield-Leeds motorway was opened to traffic on Saturday.}} The build cost was £6 million. The structure is unusual in that it is built as steel box girders, at a time when most long span bridges were being built of post-tensioned concrete deck design. The use of steel allowed a significant cost saving over alternative methods, but became controversial following two disasters involving steel bridges in 1970 (the West Gate Bridge in Australia and the Cleddau Bridge in Wales) and another in 1971 (the {{ill|Koblenz South Bridge|de|Südbrücke (Koblenz)}} in Germany). Fifty-one people were killed in these failures, leading in the UK to the formation of the Merrison Committee.{{cite book |author=Department of the Environment (Merrison Committee of Inquiry) |title=Inquiry into the Basis of Design and Method of Erection of Steel Box Girder Bridges |publisher=HMSO |location=London |year=1973 |ref=Merrison}} The report of the Merrison committee resulted in the temporary closure of two of the carriageways on the lower deck and two on the upper deck, the installation of extra steel strengthening bands around the bridge's support columns and other works which were completed in 1983. A further programme of strengthening was completed in 2006. The recent work to strengthen the bridge was a very complex operation, with a lot of the work happening inside the box beam spine. The works took over 3 years and cost £82 million (nearly 9 times the original bridge building cost, adjusting for inflation). The strengthening project won the British construction industry's Major Project Award in 2005.

Although originally designed to carry a dual 3-lane motorway on the top deck, during and subsequent to the strengthening work the M1 was reduced to 2 lanes following an EU directive on load bearing capacity to allow for the introduction of 40-tonne trucks in the UK. This arrangement allowed the third lane in each direction to join from Junction 34 to make the busy junction safer.{{cite web|url=http://www.gnn.gov.uk/content/detail.asp?NewsAreaID=2&ReleaseID=172690|title=£82 Million M1 Tinsley Viaduct strengthening work nears completion|date=10 October 2005|publisher=Highways Agency|access-date=16 November 2006}} Since the opening of the M1 junction 32 to 35a smart motorway scheme in January 2017, the viaduct once again carries 3 lanes of traffic plus hard shoulders in each direction.{{cite web|url=https://www.gov.uk/government/news/transforming-the-m1-in-yorkshire-and-the-east-midlands-find-out-more|title=Transforming the M1 in Yorkshire and the East Midlands|work=gov.uk|date=12 September 2014|access-date=12 September 2017}}

The viaduct is balanced on rollers to allow for thermal expansion and contraction, and the route weaves slightly in order to make its way past obstacles. The viaduct, due to its construction, is very flexible. Movement may be felt on the lower deck as the traffic passes overhead. The Meadowhall Shopping Centre lies in the valley to the west; to the east is the Blackburn Meadows sewage works and new biomass power station.

{{Main|Blackburn Meadows Power Station}}

File:Tinsley Towers demolition.JPG

The viaduct is one of Sheffield's most prominent landmarks, and was once made all the more so by the adjacent pair of cooling towers that were left standing for safety reasons after the demolition of the Blackburn Meadows Power Station. The cooling towers were a major point of contention over the years and were once saved from destruction only after being chosen as a nesting site by a rare bird.{{Citation needed|date=August 2008}} More recently, plans were made to turn them into a piece of public art.{{cite news |url=http://news.bbc.co.uk/1/hi/uk/5160214.stm |title=Turning towers into art |work=BBC News |publisher=BBC |date=8 July 2006|access-date=28 August 2006}} Other plans for the towers included concert halls, skate parks and a theme park.

Their iconic status, and the possibly prohibitive costs of demolishing the towers safely, looked to have cemented their status in Sheffield's future as much as they were a part of its history, until the owner of the towers (and the now-demolished power station), E.ON UK, stated its intention to demolish them once the strengthening of the viaduct made it feasible.{{cite web|url=http://pressreleases.eon-uk.com/blogs/eonukpressreleases/archive/2008/08/12/1268.aspx|title=August demolition date set for Tinsley cooling towers|date=12 August 2008|publisher=E.ON UK|access-date=12 August 2008}}

The {{convert|250|ft|m|0}} towers were demolished at 03:00 BST on 24 August 2008, though a significant portion of the north tower remained standing for a short while. The demolition attracted widespread attention. A viewing platform was set up so the public could watch the demolition.{{cite news |title=Blast demolishes landmark towers |url=http://news.bbc.co.uk/1/hi/england/south_yorkshire/7578266.stm |work=BBC News |publisher=BBC |date=24 August 2008 |access-date=24 August 2008 }} Part of the site has been converted for use as a biomass power station by the owners E.ON UK.{{cite web |url=http://eon-uk.com/generation/1490.aspx |title=E.ON UK Blackburn Meadows Green powerstation |access-date=24 August 2008 |publisher=E.ON }}{{cite web|title=E.ON's Blackburn Meadows biomass plant generates electricity {{!}} Bioenergy Insight Magazine|url=http://www.bioenergy-news.com/display_news/7963/E_ON__039_s_Blackburn_Meadows_biomass_plant_generates_electricity/|website=bioenergy-news.com|access-date=12 September 2017|date=30 June 2014}}

The Tinsley Viaduct is featured among several other locations as the site of "ground zero" for a fictional Soviet Union nuclear strike on Sheffield depicted in Threads (1984), a depiction of what might have happened had NATO and the Soviet Union entered conflict over hypothetical instability in Iran that escalated into full nuclear war. In the ensuing nuclear exchange, a one-megaton nuclear missile explodes above the Tinsley Viaduct, devastating most of surrounding Sheffield.

• List of bridges in the United Kingdom

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{{Commons category|Tinsley Viaduct}}

• [http://www.dontgo.co.uk/cooling.html Go sheffo: Cooling the Towers] Cooling towers public art competition held in 2005.
• [http://www.level-two.co.uk/adventure.php?a=giants Standing on the Shoulders of Giants] Blackburn Meadows cooling tower climb

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{{Road bridges in Yorkshire}}

Category:Bridges completed in 1968

Category:Bridges in Sheffield

Category:Bridges over the River Don, South Yorkshire

Category:Motorway bridges in England

Category:Road transport in Sheffield

Category:Steel bridges in the United Kingdom

Category:Viaducts in England

Category:M1 motorway

Category:Double-decker bridges

Category:1968 establishments in England