Editing Tsing Ma Bridge

{{short description|Suspension bridge in Hong Kong}}
{{EngvarB|date=July 2014}}
{{Use dmy dates|date=July 2014}}

{{Infobox bridge
| name                = Tsing Ma Bridge 
| native_name         = 青馬大橋
| native_name_lang    = 
| image               = Tsing Ma Bridge 2.jpg
| image_upright       = 
| alt                 = A large concrete suspension bridge.
| caption             = View from Tsing Yi
| coordinates         = {{coord|22|21|05|N|114|04|27|E|region:HK_type:landmark}}
| os_grid_reference   = 
| carries             = Trains, motor vehicles
| crosses             = [[Ma Wan Channel]]
| locale              = [[New Territories]], [[Hong Kong]]
| official_name       = 
| other_name          = 
| named_for           = 
| owner               = [[Government of Hong Kong|Hong Kong Government]]
| maint               = TIML MOM Limited<br>(under contract to [[Highways Department]])
| heritage            = 
| id                  = 
| id_type             = 
| website             = 
| preceded            = 
| followed            = 
| design              = [[Deck (bridge)|Double-decked]] [[suspension bridge]]
| material            = 
| material1           = 
| material2           = 
| length              = 
| width               = {{convert|41|m|ft|0}}
| height              = 
| depth               = 
| traversable         = 
| towpath             = 
| mainspan            = {{convert|1377|m|ft|0}}
| number_spans        = 
| piers_in_water      = 
| load                = 
| clearance_above     = 
| clearance_below     = {{convert|53|m|ft|0}} (official shipping height restriction)<ref name="debacle"/>
| lanes               = 6 (upper deck), 2 (lower deck)
| life                = 
| num_track           = 2
| track_gauge         = {{RailGauge|1432mm|lk=on}}
| structure_gauge     = 
| electrification     = 1.5 [[Volt|kV]] [[Direct current|DC]]
| architect           = 
| designer            = [[Mott MacDonald]]
| contracted_designer = 
| winner              = 
| engineering         = 
| builder             = Anglo Japanese Construction Joint Venture
| fabricator          = [[Cleveland Bridge & Engineering Company]]
| begin               = {{Start date and age|1992|5}}
| complete            = {{End date and age|1997|5}}
| cost                = HK$7.14 billion
| open                = {{start date and age|1997|05|22|df=y}}
| inaugurated         = {{Start date and age|df=yes|1997|4|27}}
| rebuilt             = 
| collapsed           = 
| closed              = 
| replaces            = 
| replaced_by         = 
| traffic             = 87,764 (2016)<ref name="2017transportdigest">{{cite web|title=Section 4: Road Tunnels and Control Areas|url=http://www.td.gov.hk/mini_site/atd/2017/en/section4_15.html|website=2017 Annual Transport Digest|publisher=Transport Department}}</ref> ([[Lantau Link]])
| toll                = No (Since 27 December 2020)
}}
{{Chinese
|t=青馬大橋
|s=青马大桥
|l=[[Tsing Yi]]-[[Ma Wan]] Great Bridge
|h=Ciang1 ma1 tai4 kiau2
|y=Ching1 ma5 daai6 kiu4
|j=Cing1 maa5 daai6 kiu4
|p=Qīngmǎ Dàqiáo
}}

'''Tsing Ma Bridge''' is a bridge in [[Hong Kong]] that connects [[Tsing Yi]] and [[Ma Wan]] islands. It is the world's [[List of longest suspension bridge spans|17th-longest span]] [[suspension bridge]], and was the second longest at the time of its completion.<ref>{{cite web|url=http://www.weirdlyodd.com/10-tallest-bridges-in-the-world/ |title=10 Tallest Bridges in the World &#124; Top Weird,Odd and Cool lists |publisher=Weirdly Odd |date=2010-12-01 |access-date=2013-04-29}}</ref> The bridge was named after the two islands it connects, namely [[Tsing Yi]] and [[Ma Wan]]. It has two decks and carries both [[Lantau Link|road]] and [[MTR|rail traffic]], which also makes it the largest suspension bridge of this type. The bridge has a main span of {{convert|1377|m|ft|0}} and a height of {{convert|206|m|ft|0}}. The span is the longest of all bridges in the world carrying rail traffic.

The {{convert|41|m|ft|adj=mid|-wide|0}} bridge deck carries six lanes of automobile traffic, with three lanes in each direction. The lower level contains two rail tracks and two sheltered carriageways used for maintenance access and traffic lanes when particularly severe [[typhoon]]s strike Hong Kong and the bridge deck is closed to traffic.<ref>[http://eprints.qut.edu.au/12796/Evaluation Evaluation of typhoon induced fatigue damage for Tsing Ma Bridge] {{Webarchive|url=https://web.archive.org/web/20200126090253/http://eprints.qut.edu.au/12796/Evaluation|date=26 January 2020}}[https://web.archive.org/web/20100608114121/http://eprints.qut.edu.au/12796/]</ref>

== History ==
=== Background ===
The Tsing Ma Bridge is the most prominent element of the [[Lantau Link]], an infrastructure project built to connect [[Lantau Island|Lantau]], Hong Kong's largest island, to the urbanised areas of the territory. Until this link opened in 1997, Lantau Island could only be accessed by water, and was completely rural. The Lantau Link was built as part of the [[Airport Core Programme]], which ultimately served to provide Hong Kong with [[Chek Lap Kok Airport|a brand new airport at Chek Lap Kok]] (off the north coast of Lantau) to replace the older, congested [[Kai Tak Airport]].

=== Construction ===
Numerous consortia bid on the contract to construct the bridge. Hyundai made the lowest bid but were disqualified for non-compliance with the financial requirements.<ref name="workstarts">{{cite news|title=Work starts on Tsing Ma contract|work=South China Morning Post|date=28 May 1992|page=35}}</ref> A Japanese bid was ruled out for being too expensive. The Anglo Japanese Construction Joint Venture, comprising [[Costain Group|Costain]], [[Mitsui]], and [[Trafalgar House (company)|Trafalgar House]], won the job.<ref name="marvel">{{cite news|last1=Davis|first1=Chris|title=Engineering marvel becomes territory's latest landmark|work=South China Morning Post|date=22 May 1997|page=1}}</ref> Construction work on the bridge began in May 1992.<ref name="workstarts"/> [[Gammon Construction]] constructed the [[Caisson (engineering)|caissons]] for the bridge towers. The framework for each caisson was floated into place and sunk, and then filled with concrete underwater.<ref name="gammon">{{cite news|title=Gammon begins bridge under the water|work=South China Morning Post|date=30 July 1992|page=26}}</ref> The two caissons on the Ma Wan side weigh 4,500 tons each, while those on the Tsing Yi side (closer to shore) each weigh about 3,000 tons.<ref name="gammon"/> Land reclamation was carried out at both ends of the bridge. The more substantial reclamation on Ma Wan was used as a work platform for construction crews.<ref name="gammon"/>

The first steel deck segment was lifted into place in late 1994.<ref name="milestone">{{cite news|last1=Wallis|first1=Keith|title=Tsing Ma milestone reached|work=South China Morning Post|date=25 October 1994|page=4}}</ref> The approach deck segments were constructed in Britain and Dubai and then shipped to Hong Kong for assembling. The main span segments were built by [[Cleveland Bridge & Engineering Company]] in the U.K. and by Mitsui in Japan.<ref name="milestone"/> The climbing cranes used to erect the tower portals were coincidentally also used on the [[HSBC Building (Hong Kong)|HSBC Main Building]] a decade earlier, as well as at [[Canary Wharf]] in the interim.<ref>{{cite news|last1=Metcalfe|first1=Tim|title=Kvaerner's expertise in building spans the years|work=South China Morning Post|date=29 April 1997|page=25}}</ref>

=== Inauguration ===
Construction was finished in May 1997. It cost HK$7.2 billion. The [[Lantau Link]], of which the bridge is an integral part, was inaugurated on 27 April 1997 by former British Prime Minister [[Margaret Thatcher]].<ref name="debacle">{{cite news|last1=Heaver|first1=Stuart|title=Tsing Ma Bridge height debacle costing Hong Kong billions|url=http://www.scmp.com/lifestyle/article/2098515/tsing-ma-bridge-height-debacle-costing-hong-kong-billions|work=South China Morning Post|date=17 June 2017}}</ref> Security was extremely tight as Thatcher was considered one of the top targets of the [[Irish Republican Army]].<ref name="secret">{{cite news|title=Security tight for Thatcher's bridge opening|work=South China Morning Post|url=http://www.scmp.com/article/193737/security-tight-thatchers-bridge-opening|date=27 April 1997|page=4}}</ref>

The commemoration ceremony began with a flotilla of police and other government vessels passing beneath the bridge, before [[Government Flying Service]] and [[Royal Air Force]] aircraft flew above the concrete towers.<ref name="scmpopening"/> Thatcher, Chief Secretary [[Anson Chan]], and Governor [[Chris Patten]] then switched on the bridge lights and drove across the span with other dignitaries. The celebration concluded with a 20-minute firework and laser show, featuring fire pouring from the length of the bridge, engineered by the Pyromagic Productions company.<ref name="scmpopening"/> Chief Executive-designate [[Tung Chee-hwa]] declined to attend as he said he would rather meet with officials in Guangdong.<ref name="scmpopening">{{cite news|last1=Delfino|first1=Brendan|title=Territory's new gateway opens in spectacular style|work=South China Morning Post|date=28 April 1997|page=1}}</ref><ref>{{cite news|last1=Wallen|first1=David|last2=Lo|first2=Alex|title=Firework harmony hopes up in smoke|work=South China Morning Post|date=30 April 1997|page=3}}</ref>

The opening ceremony was highly anticipated and attracted more than 100,000 spectators, most of them standing along [[Castle Peak Road]], which was closed to road traffic.<ref name="spotlight">{{cite news|last1=Lee|first1=Stella|title=Spotlight on crowd control for handover|work=South China Morning Post|date=29 April 1997}}</ref> The [[Tuen Mun Road]] was also closed to traffic from 7:40 to 8:20 pm, and a 20-minute fireworks display, costing HK$5 million, began at 8 pm.<ref name="secret"/><ref>{{cite news|last1=Flint|first1=John|title=Lantau link fireworks not for the faint-hearted|work=South China Morning Post|date=17 April 1997|page=5}}</ref> [[MTR]], [[Citybus (Hong Kong)|Citybus]], and [[Kowloon-Canton Railway Corporation|KCR Corporation]] arranged special transport services for the event.<ref>{{cite news|last1=Lo|first1=Alex|title=Long march home faces fireworks fans|work=South China Morning Post|date=26 April 1997|page=5}}</ref> More than 2,300 police officers were deployed, and the crowd control exercise was studied by the police for its relevance to the upcoming [[Transfer of sovereignty over Hong Kong|Handover]] ceremony.<ref name="spotlight"/> Three boating accidents occurred during the bridge inauguration.<ref name="spotlight"/>

The Lantau Link was opened to traffic on 22 May 1997 at 8:00 am. Cars queued for four hours before police opened the bridge.<ref name="roadopen">{{cite news|last1=Delfino|first1=Brendan|title=Woman injured as hundreds cross link|work=South China Morning Post|date=23 May 1997|page=4}}</ref> Snaking queues also formed at bus stations at 7:00 am as passengers sought to view the new infrastructure as well as the [[North Lantau New Town]], which was still under construction.<ref name="roadopen"/>

The first road accident on the Lantau Link occurred on the Tsing Ma Bridge on 23 May 1997. Two motorcyclists were injured in a collision with a lorry.<ref name="chaos">{{cite news|last1=Flint|first1=John|last2=Lo|first2=Clifford|title=Police issue warning after crash on Link|work=South China Morning Post|date=24 May 1997|page=4}}</ref> The police warned the public not to rush to use the new bridges and highways to avoid causing chaos.<ref name="chaos"/>

Two special bus routes came into operation on 24 May 1997 for passengers to view the Lantau Link. The X21 and X31 buses ran from [[Tai Kok Tsui]] and [[Tsuen Wan]], respectively.<ref name="chaos"/>

== Operation ==
The Tsing Ma Bridge crosses the [[Ma Wan Channel]], linking the islands of Tsing Yi and Ma Wan. It is part of the [[Lantau Link]], which links the [[New Territories]] and [[Lantau Island]], and eventually leads to the [[Hong Kong International Airport]] on [[Chek Lap Kok]] via the [[North Lantau Highway]].

The Tsing Ma Bridge is an important gateway to Lantau Island. It is part of the [[Route 8 (Hong Kong)|Route 8 expressway]], which connects the Lantau Link, the [[West Kowloon]] expressway, [[Cheung Sha Wan]] and [[Sha Tin]]. The rail line is shared by the [[MTR]]'s [[Tung Chung line]] and [[Airport Express (MTR)|Airport Express]].

The bridge, together with other highway, bridge and tunnel connections in the area, are part of the [[Tsing Ma Control Area]] under the Tsing Ma Control Area Ordinance (Cap. 498) in [[Law of Hong Kong|Hong Kong Law]].<ref>{{cite web |url=http://www.pbworld.com/capabilities_projects/tsing_ma_control_area_traffic_control_and_surveillance_system.aspx |title=Parsons Brinckerhoff: Tsing Ma Control Area, Traffic Control and Surveillance System |publisher=Pbworld.com |access-date=2013-04-29 |archive-url=https://web.archive.org/web/20130220081813/http://www.pbworld.com/capabilities_projects/tsing_ma_control_area_traffic_control_and_surveillance_system.aspx |archive-date=20 February 2013 |url-status=dead |df=dmy-all }}</ref> The control area has been managed by [[Tsing Ma Management Limited]] since opening. The control area's traffic management system was developed by [[Delcan Corporation]] of [[Toronto]], [[Ontario]], [[Canada]]. Special regulations and by-laws apply in the area.

Along with the [[Ting Kau Bridge]] and [[Kap Shui Mun Bridge]], the bridge is monitored by the [[Wind and Structural Health Monitoring System]] (WASHMS). [[Surveillance cameras]] are also installed on the bridge to record traffic conditions. The video is available at the government website.<ref>{{Cite web |url=http://traffic.td.gov.hk/ |title=Surveillance cameras of Transportation Department |access-date=29 October 2004 |archive-date=5 June 2019 |archive-url=https://web.archive.org/web/20190605135350/http://traffic.td.gov.hk/ |url-status=dead }}</ref> It is updated every two minutes.

There are no longer tolls on Lantau Link since 27 December 2020. Before, the fee of using Tsing Ma bridge for motorcycles, private cars, public double-decker buses and heavy goods vehicles are [[Hong Kong dollar|HK$]]10, $15, $30 and $40 respectively, charged both directions.<ref name=everytrail943264>{{Cite web |url=http://www.everytrail.com/view_trip.php?trip_id=943264%2FToll |title=plaza |access-date=4 December 2018 |archive-url=https://web.archive.org/web/20171209044032/http://www.everytrail.com/view_trip.php?trip_id=943264%2FToll |archive-date=9 December 2017 |url-status=dead |df=dmy-all }}</ref> The normal [[speed limit]] on the bridge is {{convert|80|km/h|mph}}, subject to lowering in the event of road work or strong wind. Traffic may also be directed to the sheltered carriageways on the lower deck when there are very strong winds. There are no pavements on the bridge.

== Design ==
[[File:Park Island Aerial.jpg|thumb|Ma Wan abutment]]
[[File:Tsing ma bridge.png|thumb|Tsing Ma bridge viewed from Ma Wan under [[Fog|dense fog]]]]
The bridge was designed by [[Mott MacDonald]].<ref>{{cite news|last1=Clarke|first1=Rachel|title=Construction 'Oscars' go to Tsing Ma span|work=South China Morning Post|date=25 October 1997|page=4}}</ref> The firm designed an early iteration of the bridge in 1982, with a two lane dual carriageway on the top deck, and a light railway on the lower deck.<ref name="dream">{{cite news|title=New bridge a dream come true|work=South China Morning Post|date=28 May 1992|page=35}}</ref> The bridge was redesigned beginning in 1989 to account for the three lane dual highway and the heavier airport railway. The designers were inspired by the [[Forth Bridge]] in Scotland and the [[Severn Bridge]] in England.<ref name="dream"/>

=== Wind tunnel testing ===
The objectives of the [[wind tunnel]] studies were to demonstrate the safety of the structure under construction and once completed, both with respect to [[aerodynamic]] [[flight dynamics|stability]] as well as the possible effects of extreme typhoon wind speeds. A further objective was to provide dynamic response data at several key locations to compare with full scale data from the ongoing monitoring program, conducted by the [[Highways Department]] of Hong Kong.

A 1 to 80 scale section model of the deck in the erection stage, and a 1 to 400 scale full aeroelastic model of the entire bridge were constructed. It is a [[Monte Carlo method|Monte-Carlo]] simulation of the typhoon wind climate. The full model was tested in different stages of construction in turbulent boundary layer flow, complete with the local [[topography]] to model the wind conditions at the site. The model tests identified critical stages of erection that allowed the construction schedule of the bridge to be tailored to avoid the typhoon season. The comparison of model test results and the full scale monitoring will assist engineers to better understand the behaviour of long span bridges in wind and to improve current design methods.

=== Major components ===
[[File:Cable band for Tsing Ma Bridge.jpg|upright|thumb|left|Cable band for Tsing Ma Bridge undergoing dimensional inspection]]

There is one tower located on [[Wok Tai Wan]] of Tsing Yi side and another on a man-made island {{convert|120|m|ft}} off the coast of Ma Wan.<ref>{{cite web |url=http://www.cityu.edu.hk/CIVCAL/book/bridge.html |title=Tsing Ma Bridge |publisher=Cityu.edu.hk |access-date=2013-04-29 |archive-date=16 May 2019 |archive-url=https://web.archive.org/web/20190516221456/http://www.cityu.edu.hk/CIVCAL/book/bridge.html |url-status=dead }}</ref> Both towers are {{convert|206|m|ft}} above sea level and founded on relatively shallow bedrock. The towers are two-legged with trusses at intervals, in the form of portal beam design. The legs were constructed with high-strength concrete of 50 MPa (concrete grade 50/20) strength, using a slipform system in a continuous operation.

The pulling force in the main suspension cables is taken up by large gravity anchorages located at both ends of the bridge.<ref>{{cite web |url=http://www.geo-design.co.uk/projects/foundations/tsing-ma-bridge-anchorages-hong-kong/ |archive-url=https://archive.today/20130420110230/http://www.geo-design.co.uk/projects/foundations/tsing-ma-bridge-anchorages-hong-kong/ |url-status=dead |archive-date=2013-04-20 |title=Tsing Ma Bridge Anchorages, Hong Kong |publisher=Geo-Design |access-date=2013-04-29 }}</ref> They are massive concrete structures deeply seated on bedrock on the landside of Tsing Yi and Ma Wan island. The total weight of concrete used in the Tsing Yi anchorage is 200,000 tonnes, and Ma Wan Anchorage has 250,000 tonnes of concrete.

The cables were constructed by an aerial spinning process. The process involved drawing wires from a constant-tension supply, and pulling loops of these wires from one anchorage to the other, passing through a 500-tonne cast-iron saddle on top of each bridge tower seating the cable. A total of 70,000 galvanised wires of {{Convert|5.38|mm|in|adj = on}} diameter were placed and adjusted to form the two {{convert|1.1|m|ft|adj = on}} diameter main cables.

The steelwork for the deck structure was fabricated in Britain and Japan. After delivery, they were further processed and assembled in [[Dongguan]], China into standard deck modules. A total of 96 modules, each {{convert|18|m|ft}} long and about 480 tonnes in weight, were prepared. These deck modules were brought to the site by specially designed barges and raised into the deck position by a pair of [[strand jack]] gantries that could manoeuvre along the main cable.

The approach span on the Tsing Yi side is similar in form and cross-section to the suspended deck, but is supported on piers instead by cables. The first span was assembled on the ground and raised into position using strand jacks. Further construction then proceeded in cantilever in smaller sections, using derrick cranes stationed on the deck level. An [[expansion joint]] which allowed for a maximum thermal movement of ± {{convert|835|mm|in}} was also provided and located inside the approach span.

The bridge parapets are of a special design by Hong Kong standards, comprising high-tension steel strands anchored on metal posts.<ref name=20030716legco>{{cite web|title=Tuen Mun Road Traffic Incident – The Use of Vehicular Parapets and Proposed Way Forward|url=http://www.legco.gov.hk/yr02-03/english/panels/tp/papers/tp0717cb1-2218-1e.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.legco.gov.hk/yr02-03/english/panels/tp/papers/tp0717cb1-2218-1e.pdf |archive-date=2022-10-09 |url-status=live|publisher=Legislative Council Panel on Transport|date=16 July 2003}}</ref>

===Ship impact protection===
The rock seawalls around the base of each bridge tower are capable of halting a 220,000 tonne ship moving at eight knots.<ref name="gateway">{{cite news|title='Gateway to China' plan moves ahead|work=South China Morning Post|date=27 November 1992|page=62}}</ref>

== Tourism ==
[[File:TsingMaBridgeMarathon.jpg|thumb|upright|The [[Hong Kong Marathon]] utilised the bridge until 2016. Because of complaints over traffic, organisers were forced to remove the bridge from the marathon course.]]
The Tsing Ma Bridge has become a scenic spot as well as a landmark. There is a visitor centre, the [[Lantau Link Visitors Centre and Viewing Platform]], located at the northwest corner of Tsing Yi Island, near the bridge's Tsing Yi end. From the Scenery Viewing Platform, one can also see the [[Ting Kau Bridge]] and [[Kap Shui Mun Bridge]]. The bridge can also be seen from the [[Airport Core Programme Exhibition Centre]] located about {{convert|2|km|mi}} north of the bridge.

You can also get a great view of the bridge at several points during the Tsing Yi Nature Trails hike, which can be easily accessed by several buses.

== See also ==
* [[List of bridges in China]]
* [[List of longest suspension bridge spans]]
* [[List of tunnels and bridges in Hong Kong]]
* [[List of road–rail bridges]]

== References ==
{{Reflist|30em}}

== Further reading ==
{{refbegin}}
* Y. L. Xu, J. M. Ko and Z. Yu. "Modal analysis of tower-cable system of Tsing Ma long suspension bridge". ''Engineering Structures''. Volume 19, Issue 10, October 1997, pp.&nbsp;857–867.
{{refend}}

== External links ==
{{Commons category|Tsing Ma Bridge}}
* {{Structurae|id=20000082|title=Tsing Ma Bridge}}
* [https://web.archive.org/web/20100728081752/http://www.cityu.edu.hk/CIVCAL/book/bridge.html Tsing Ma Bridge description from City University, Hong Kong] (archive)

{{coord|22|21|05|N|114|04|27|E|type:landmark|display=title}}
{{sequence
|prev=[[Nam Wan Tunnel]]
|list=[[Route 8 (Hong Kong)|Hong Kong Route 8]]<br>[[Image:HK Route8.svg|x20px]]<br>Tsing Ma Bridge
|next=[[Ma Wan Viaduct]]
}}
{{HK routes|r8;}}
{{Bridges in Hong Kong|state=expanded}}
{{NTTaxi}}
[[Category:Bridges completed in 1997]]
[[Category:Bridges in Hong Kong]]
[[Category:Route 8 (Hong Kong)]]
[[Category:Road-rail bridges]]
[[Category:Landmarks in Hong Kong]]
[[Category:Ma Wan]]
[[Category:Suspension bridges in Hong Kong]]
[[Category:Railway bridges in Hong Kong]]
[[Category:Tsing Yi]]
[[Category:1997 establishments in Hong Kong]]