Editing Tsing Ma Bridge (section)

=== 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>