View source for Sydney Harbour Tunnel

{{Short description|Motorway tunnel in Sydney, Australia}}
{{Use dmy dates|date=June 2020}}
{{Use Australian English|date=March 2018}}
{{Infobox tunnel
|name         = Sydney Harbour Tunnel
|image        = Cahill Expressway and Sydney Harbour Tunnel, from Conservatorium Road, Sydney, New South Wales (2011-03-23) 02.jpg
|caption      = Southern end of the Sydney Harbour Tunnel, showing the northbound entry (L) and southbound exit (R)
|location     = [[Port Jackson]]
|coordinates  = {{coord|33.85260|S|151.21187|E|source:placeopedia}}
|route        = {{AUshield|NSW|M1|size=30px}}
|status       = Active
|start        = {{AUshield|NSW|M1}} [[Warringah Freeway]]
|end          = {{AUshield|NSW|M1}} [[Cahill Expressway]]
|startwork    = February 1988
|opened       = 30 August 1992
|close        = 
|owner        = [[Transport for NSW]]
|operator     = [[Ventia]]
|traffic      = Automotive
|toll         = Time of day tolling (southbound only)
|vpd          = 96,000 (2017)
|length       = {{convert|2.8|km|abbr=on}}
|lanes        = 4
|speed        = {{convert|80|km/h|abbr=on}}
|hielevation  = 
|lowelevation = 
|height       = {{convert|4.4|m|ftin|abbr=on}} vehicle clearance,
|width        = {{convert|10.5|m|ftin|abbr=on}}<ref name="low" />
|shipping_clearance_above ={{convert|16|m|ft|abbr=on}}<ref name="low">Muhammad, Imran; Low, Nicholas (December 2006). [http://www.abp.unimelb.edu.au/gamut/pdf/tunnel-background-report.pdf Mega Projects in Transport and Development: Background in Australian Case Studies] {{Webarchive|url=https://web.archive.org/web/20090702112931/http://www.abp.unimelb.edu.au/gamut/pdf/tunnel-background-report.pdf |date=2 July 2009 }}. Australasian Centre for the Governance and Management of Urban Transport. Retrieved 3 July 2009.</ref>
|depth_below_water = {{convert|25|m}}
|grade        = }}

The '''Sydney Harbour Tunnel''' is a twin-tube road tunnel in Sydney, Australia. The tunnel was completed and opened to traffic in August 1992 to provide a second vehicular crossing of [[Port Jackson|Sydney Harbour]] to alleviate congestion on the [[Sydney Harbour Bridge]]. It is one of two transportation tunnels under the harbour, the other being twin rail tunnels used by [[Metro North West & Bankstown Line|Sydney Metro]].<ref>{{cite web |url=http://www.sydneymetro.info/article/planning-approval-sydney-metro-under-harbour |title=Planning approval for Sydney Metro under the Harbour |website=[[Sydney Metro]] |publisher=New South Wales Government |date=10 January 2017 |access-date=18 January 2017 |archive-date=18 January 2017 |archive-url=https://web.archive.org/web/20170118222923/http://www.sydneymetro.info/article/planning-approval-sydney-metro-under-harbour |url-status=live }}</ref><ref>{{cite news |last=McNab |first=Heather |url=http://www.dailytelegraph.com.au/newslocal/central-sydney/twin-tunnels-under-sydney-harbour-given-green-light-for-metro-project/news-story/7923884c3fef395be8b1a96aeca2bb9e |title=Twin tunnels under Sydney Harbour given green light for metro project |website=[[Daily Telegraph (Sydney)|The Daily Telegraph]] |date=11 January 2017 |access-date=18 January 2017 |archive-date=8 March 2017 |archive-url=https://web.archive.org/web/20170308043618/http://www.dailytelegraph.com.au/newslocal/central-sydney/twin-tunnels-under-sydney-harbour-given-green-light-for-metro-project/news-story/7923884c3fef395be8b1a96aeca2bb9e |url-status=live }}</ref>

The tunnel joins the [[Warringah Freeway]] at [[North Sydney, New South Wales|North Sydney]] and the [[Cahill Expressway]] at the entrance to the Domain Tunnel. It has two lanes in each direction, and runs at an angle of approximately thirty degrees (north to south) to the Sydney Harbour Bridge, which has eight lanes, with a tidal flow operation. In 2017, the tunnel was carrying around 96,000 vehicles per day.<ref>[https://web.archive.org/web/20220123014446/https://www.infrastructureaustralia.gov.au/sites/default/files/2021-05/Western%20Harbour%20Tunnel%20and%20Warringah%20Freeway%20Upgrade%20-%20Project%20Evaluation%20Summary_1.pdf Western Harbur Tunnel and Warringah Freeway Upgrade] [[Infrastructure Australia]] 15 April 2021</ref><ref>{{cite news |url=http://smh.drive.com.au/motor-news/harbour-tunnel-still-good-value-govt-20081211-1465w.html |title=Harbour tunnel still good value: govt |work=[[Sydney Morning Herald]]|author=Ralston, Nick |date=11 December 2008 |access-date=1 February 2011 |url-status=dead |archive-url=https://web.archive.org/web/20120324030459/http://smh.drive.com.au/motor-news/harbour-tunnel-still-good-value-govt-20081211-1465w.html |archive-date=24 March 2012  }}</ref>

== Construction ==
[[File:Sydney Harbour Bridge, 2007.JPG|thumb|left|Alterations to the northern end pylons of the Harbour Bridge were required to build the tunnel.]]
The tunnel is made up of three sections: twin {{convert|900|m|adj=on}} land tunnels on the north shore, twin {{convert|400|m|adj=on}} land tunnels on the south shore and a {{convert|960|m|adj=on}} [[immersed tube]] (IMT) structure. The tunnel falls about {{convert|55|m}} from the northern entrance and about {{convert|35|m}} from the southern entrance to its deepest point, {{convert|25|m}} below sea level. The construction was undertaken by [[Thiess (company)|Thiess Contractors]].<ref>{{cite book|url=https://books.google.com/books?id=sadvDwAAQBAJ&q=Thiess+Sydney+Harbour+Tunnel&pg=PA165|title=The Playful Entrepreneur: How to Adapt and Thrive in Uncertain Times|first1=Mark|last1=Dodgson|first2=David M.|last2=Gann|publisher=[[Yale University Press]]|year=2018|isbn=978-0300233926|page=165|access-date=17 December 2020|archive-date=24 September 2023|archive-url=https://web.archive.org/web/20230924095219/https://books.google.com/books?id=sadvDwAAQBAJ&q=Thiess+Sydney+Harbour+Tunnel&pg=PA165|url-status=live}}</ref>

The IMT structure consists of eight [[precast concrete]] units. The units were constructed over {{convert|100|km}} away in a casting basin at [[Port Kembla, New South Wales|Port Kembla]] and then towed to [[Sydney Harbour]]. A trench was dredged before the arrival of the IMTs and then the IMTs were lowered into the trench by a system of pontoons and control towers. After the IMTs were in place, the trenches were backfilled and then a [[Riprap|rock armour]] was placed over the top to protect the units against marine hazards, such as [[anchor]]s or sinking vessels. The land tunnels were constructed by a combination of driving and [[Tunnel_construction#Cut-and-cover|cut-and-cover techniques]], designed to be strong enough to withstand the impact of earthquakes.
[[File:Sydney Harbour Tunnel.jpg|thumb|Interior, heading northbound]]

=== Ventilation ===
The northern end pylons of the [[Sydney Harbour Bridge]] were altered to allow for air exhaust from the tunnel to rise over the harbour. Bradfield Park on the northern side of the bridge also has air intakes. Fresh air is drawn by an underground ventilation station on the north shore and is pumped to all sections of the tunnel through vented ducts. The air supply uses fourteen axial flow fans, each up to {{convert|2.5|m}} in diameter.  The exhaust uses sixteen (eight in each northern pylon tower) fans that draw exhaust air through two underground ducts from the tunnel ventilation station and transfer the air to the top of the pylon.  They can expel it at up to {{convert|1500|m³/s|abbr=on}} – equivalent to changing all the air in the tunnel every two minutes<ref name=cory>{{cite book |author=Cory, Bill|title=Fans & ventilation: a practical guide |publisher=[[Elsevier]] in association with Roles & Assoc |location=Amsterdam; Boston |year=2005 |isbn=0-08-044626-4 |type=hardback |postscript=(reproduced from the original published in ''[[Daily Telegraph (Sydney)|The Daily Telegraph-Mirror]]'' Harbour Tunnel souvenir). |pages=17–18}}</ref> with the capability of running in reverse in an emergency and all fans are rated for smoke extraction. Each of the fans has a duty of {{convert|53|to|103|m³/s|abbr=on}}.  The testing of the fans was one of the most comprehensive ever, covering flowrate and pressure, power measurements, sound levels, bearing vibration, x-raying of all impeller components, high-temperature tests at {{convert|200|C|F}} for two hours, impeller strain, and 24-hour run tests for reversals.<ref name=cory/>

== Operations and maintenance ==
The Harbour Tunnel was a partnership between the New South Wales government and private investors by tender. [[Broadspectrum|Transfield]] and [[Kumagai Gumi]] formed a 50/50 joint venture company which constructed the tunnel under contract; with a 30-year operating contract, including revenue collection and maintenance, from 1992 until 2022. As a result of the 1997 separation of assets of Transfield and the creation of the [[Tenix]] group (owned by Olbia), the ongoing 30-year operating contract for management of the tunnel was split between Kumagai Gumi (50%), Transfield (25%) and Olbia (25%).<ref>{{cite web|url=https://www.transfield.com.au/investments|title=Investments|website=[[Broadspectrum|Transfield]]|access-date=30 August 2021|archive-date=30 August 2021|archive-url=https://web.archive.org/web/20210830014420/https://www.transfield.com.au/investments|url-status=live}}</ref>

The total construction cost of the project was $554&nbsp;million.<ref name=SMH2June2017>{{Cite news|url=http://www.smh.com.au/national/jitters-about-sydney-harbour-tunnel-loan-20071212-1gly.html|title=Jitters about Sydney Harbour Tunnel loan|last=Carter|first=Paul|date=12 December 2007|work=Sydney Morning Herald|access-date=2 June 2017|archive-date=20 January 2019|archive-url=https://web.archive.org/web/20190120043321/https://www.smh.com.au/national/jitters-about-sydney-harbour-tunnel-loan-20071212-1gly.html|url-status=live}}</ref> $223&nbsp;million of this was an interest-free loan from the NSW Government, to be repaid at the conclusion of the operating contract in August 2022 when the tunnel would be transferred to public ownership.<ref name=SMH2June2017/> The government had also guaranteed an Ensured Revenue Stream (ERS) to the operator, whereby it makes up the shortfall between toll collections and the guaranteed amount.<ref name=Audit>{{Cite web|url=http://www.audit.nsw.gov.au/ArticleDocuments/166/17_Vol_6_2008_Roads_And_Traffic.pdf.aspx?Embed=Y|title=Auditor-General's Report to Parliament 2008 Volume Six – Roads and Traffic Authority|last=Achterstraat|first=Peter|date=December 2008|website=Audit Office of New South Wales|access-date=2 June 2017|archive-date=27 March 2016|archive-url=https://web.archive.org/web/20160327053459/http://www.audit.nsw.gov.au/ArticleDocuments/166/17_Vol_6_2008_Roads_And_Traffic.pdf.aspx?Embed=Y|url-status=live}}</ref> As toll revenues have been below the projected amount, in 2008 for example, the government paid the operator $58.9&nbsp;million, with the total amount forecast to be $1.1&nbsp;billion from 2008 to 2022.<ref name=Audit/> The NSW Auditor-General had also raised concerns that the tunnel's expenses may make the operating company default on the $223&nbsp;million loan,<ref>{{Cite web|url=http://www.audit.nsw.gov.au/ArticleDocuments/160/21_Vol_6_2007_Roads_And_Traffic.pdf.aspx?Embed=Y|title=Auditor-General's Report to Parliament 2007 Volume Six – Roads and Traffic Authority|last=Achterstraat|first=Peter|website=Audit Office of New South Wales|access-date=2 June 2017|archive-date=29 March 2016|archive-url=https://web.archive.org/web/20160329123523/http://www.audit.nsw.gov.au/ArticleDocuments/160/21_Vol_6_2007_Roads_And_Traffic.pdf.aspx?Embed=Y|url-status=live}}</ref> however the government remained confident in it.<ref name=SMH2June2017/>

With the 30-year operating contract about to expire, in April 2022, the state government signed a 15-year contract with [[Ventia]] for the asset management, operations and maintenance of the Sydney Harbour Tunnel as well as the under-construction [[Western Harbour Tunnel]].<ref>{{cite web|url=https://www.transport.nsw.gov.au/news-and-events/media-releases/asset-manager-confirmed-for-harbour-tunnels|title=Asset Manager confirmed for Harbour Tunnels|publisher=[[Transport for NSW]]|date=11 April 2022|access-date=9 September 2022|archive-date=9 September 2022|archive-url=https://web.archive.org/web/20220909005836/https://www.transport.nsw.gov.au/news-and-events/media-releases/asset-manager-confirmed-for-harbour-tunnels|url-status=live}}</ref> Tolling arrangements were unrelated to the new agreement. On 1 September 2022, the tunnel reverted back to state government ownership.

== Tolls ==
In 2006 the New South Wales government announced that all cash tolls on the [[Sydney Orbital Network]] would cease by 2010.<ref>{{cite news |url=http://www.news.com.au/dailytelegraph/story/0,22049,21615620-5006009,00.html |work=The Daily Telegraph |title=Sydney toll network dumps coins |location=Australia |date=25 April 2007 |author=Aston, Heath |access-date=3 August 2011 }}</ref> The Sydney Harbour Tunnel went fully electronic in July 2007 with both [[e-TAG]] and e-pass video tolling arrangements in use, similar to technologies used by the [[Westlink M7]], [[Cross City Tunnel]] and the [[Lane Cove Tunnel]].<ref>{{cite news |url=http://www.news.com.au/adelaidenow/story/0,22606,22023173-5001021,00.html |work=[[News.com.au]]|title=Drivers' gridlock on e-tags |location=Australia |date=5 July 2007 |author=Aston, Heath |access-date=3 August 2011 }}</ref> This measure has substantially eased the traffic jams heading towards the electronic gantries, and providing increased convenience and time savings. The Sydney Harbour Tunnel attracts a varying toll (that was introduced in 2009) of between $2.50 and $4.00, depending on the time of day.<ref>{{cite news |url=http://www.dailytelegraph.com.au/news/peak-hour-tolls-on-the-harbour-bridge-and-tunnel-could-be-scrapped/story-e6freuy9-1226097152657 |work=The Daily Telegraph |title=Peak-hour tolls on the Harbour Bridge and Tunnel could be scrapped |location=Australia |date=19 July 2011 |author=Haynes, Rhys |access-date=3 August 2011 |archive-date=7 October 2012 |archive-url=https://web.archive.org/web/20121007072857/http://www.dailytelegraph.com.au/news/peak-hour-tolls-on-the-harbour-bridge-and-tunnel-could-be-scrapped/story-e6freuy9-1226097152657 |url-status=live }}</ref> The toll is levied on the southbound approach to the tunnel entrance.

Until July 2022 it was unannounced whether tolls would continue after the transfer of ownership to the state government on 1 September 2022.<ref>{{cite web|url=https://www.smh.com.au/national/nsw/plans-for-sydney-harbour-tunnel-tolls-to-be-revealed-very-soon-20210131-p56y4l.html|title=Plans for Sydney Harbour Tunnel tolls to be revealed 'very soon'|publisher=Sydney Morning Herald|date=31 January 2021|access-date=30 August 2021|archive-date=30 August 2021|archive-url=https://web.archive.org/web/20210830014813/https://www.smh.com.au/national/nsw/plans-for-sydney-harbour-tunnel-tolls-to-be-revealed-very-soon-20210131-p56y4l.html|url-status=live}}</ref> It was eventually announced by the state government that the toll would continue, to be used for maintenance just like the Sydney Harbour Bridge.<ref>{{cite web | url=https://www.smh.com.au/national/nsw/sydney-harbour-tunnel-tolls-to-stay-deeper-tunnel-possible-for-new-crossing-20220727-p5b4xb.html | title=Sydney Harbour Tunnel tolls to stay, deeper tunnel possible for new crossing | date=27 July 2022 | access-date=2 August 2022 | archive-date=2 August 2022 | archive-url=https://web.archive.org/web/20220802014232/https://www.smh.com.au/national/nsw/sydney-harbour-tunnel-tolls-to-stay-deeper-tunnel-possible-for-new-crossing-20220727-p5b4xb.html | url-status=live }}</ref> Along with the Bridge, tolls for the Tunnel rose in October 2023 for the first time in 14 years.<ref>[https://web.archive.org/web/20230924072042/https://www.nsw.gov.au/media-releases/sydney-harbour-bridge-and-tunnel-tolls-to-rise Sydney Harbour Bridge and Tunnel tolls to rise] Transport for NSW 23 September 2023</ref>

== Exits and interchanges ==
{{AUSinttop}}
{{NSWint
|LGA=[[North Sydney Council]]
|location=North Sydney
|km=0.0
|road={{AUshield|NSW|M1}} [[Warringah Freeway]] (M1) [[Newcastle, New South Wales|Newcastle]], [[Brisbane]]
|notes=Northern end of tunnel}}
{{Jcttunnel
|river=[[Port Jackson]]
|km=
|tunnel=Sydney Harbour Tunnel
}}
{{NSWint
|LGA=[[City of Sydney]]
|location=Sydney
|km=2.8
|road={{AUshield|NSW|M1|+|airport}} [[Cahill Expressway]] (M1) [[Sydney Airport]], [[Wollongong]], [[Canberra]]
|notes=Southern end of tunnel}}
{{jctbtm}}

== History ==
The tunnel was opened to the public to walk through from North Sydney (Falcon Street) to Eastern Sydney (The Domain) on 30 August 1992. The proceeds of the tickets sold for this event were donated to the [[Royal Institute for Deaf and Blind Children]].

The tunnel opened to traffic on 31 August 1992.<ref>{{cite web |url=http://www.rta.nsw.gov.au/roadprojects/projects/building_sydney_motorways/harbour_crossings/harbour_tunnel.html |title=Sydney Harbour Tunnel |work=Building Sydney motorways |publisher=[[Roads & Maritime Services]] |date=31 October 2011 |access-date=5 March 2012 |archive-date=27 December 2011 |archive-url=https://web.archive.org/web/20111227090309/http://www.rta.nsw.gov.au/roadprojects/projects/building_sydney_motorways/harbour_crossings/harbour_tunnel.html |url-status=live }}</ref>

==References==
{{Reflist}}

==External links==
{{commons category}}
*{{cite journal |author=Pratley, Juliet |year=1993 |title=Sydney Harbour Tunnel |journal=Concrete International |volume=15 |number=7 |pages=19–23}}

{{Crossings navbox
|structure=Crossings
|place=[[Port Jackson]]
|bridge=Sydney Harbour Tunnel
|bridge signs={{AUshield|NSW|M1|size=30px}}
|upstream=[[Sydney Harbour Bridge]]
|upstream signs=
|downstream=[[Tasman Sea]]<br /><small>([[Spit Bridge]] on [[Middle Harbour]])</small>
|downstream signs=}}

{{Road infrastructure in Sydney}}

[[Category:Tunnels in Sydney]]
[[Category:Toll tunnels in Australia]]
[[Category:Transport in Sydney]]
[[Category:Undersea tunnels in Oceania]]
[[Category:Immersed tube tunnels in Oceania]]
[[Category:Public–private partnership projects in Australia]]
[[Category:Tunnels completed in 1992]]
[[Category:Highway 1 (Australia)]]
[[Category:Sydney Harbour]]
[[Category:Road tunnels in Australia]]
[[Category:1992 establishments in Australia]]