Tsing Ma BridgeEdit profile
The Tsing Ma Bridge is a bridge in Hong Kong. It is the world's seventh-longest span suspension bridge, and was the second longest at time of completion. The bridge was named after two of the islands at its ends, namely Tsing Yi and Ma Wan . It has two decks and carries both road and rail traffic, which also makes it the largest suspension bridge of this type. The bridge has a main span of 1,377 metres (4,518 ft) and a height of 206 metres (676 ft). The span is the largest of all bridges in the world carrying rail traffic.
The 41 metres (135 ft) wide bridge deck carries six lanes of automobile traffic, with three lanes in each direction. The lower level contains two rail tracks. There are also two sheltered carriageways on the lower deck for maintenance access and as backup for traffic when particularly severe typhoons strike Hong Kong. Though road traffic would need to be closed in that case, trains could still get through in either direction.History
Construction of the bridge was carried out by a Costain / Mitsui / Trafalgar House joint venture. Construction work of the bridge began in May 1992 and ended in May 1997. It cost HK$7.2 billion. The Lantau Link, of which the bridge is an integral part, was opened on April 27, 1997. The ceremony was inaugurated by the former British Prime Minister Margaret Thatcher.Operation
The Tsing Ma Bridge links Tsing Yi island on the east to Ma Wan island on the west over Ma Wan Channel. It is part of the Lantau Link, which, with two long span bridges links the New Territories and Lantau Island, and eventually leads to the Hong Kong International Airport on Chek Lap Kok via North Lantau Highway. The other bridge is the Kap Shui Mun Bridge linking Ma Wan to Lantau Island over Kap Shui Mun. The two bridges are connected over Ma Wan by Ma Wan Viaduct.
The Tsing Ma Bridge has been an important gateway to Lantau Island. It is Route 8 expressway, which connects the Lantau Link, the West Kowloon expressway, Cheung Sha Wan and Shatin. The rail line is part of MTR's Tung Chung Line and 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 Hong Kong Law. 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. Special regulations and by-laws are carried out in the area.
Along with the Ting Kau Bridge and Kap Shui Mun Bridge, the bridge is closely monitored by the Wind and Structural Health Monitoring System (WASHMS). Surveillance cameras are also installed over the bridge to record traffic conditions. The video is available at the government website. It is updated every two minutes.
Toll payable on the Lantau Link, of which Tsing Ma Bridge is part, for motor cycle, private car, public double-decked bus and heavy goods vehicle are HK$20, $30, $60 and $80 respectively, payable only for the direction from Lantau to Tsing Yi. The normal speed limit on the bridge is 80 km/h, 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 is no sidewalk on the Bridge. Parking is also prohibited on the bridge.Design
The bridge was designed by Mott MacDonald.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 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 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 in order 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
Tsing Ma Bridge has become a favourite scenic spot as well as a famous landmark. In order to watch and get further information about it, one can go to the Lantau Link Visitor Centre and Viewing Platform which is located at the northwest corner of Tsing Yi Island, just next to the Bridge's Tsing Yi end. Pictures and the structure of the Lantau Link and Ting Kau Bridge are on display at the Centre. The Visitors Centre is opened from 10:00 am to 5:00 p.m. on weekdays (closed on Wednesday); from 10:00 am to 6:30 p.m. on Saturdays, Sundays and most of the public holidays. From the Scenery Viewing Platform, one can also see the Ting Kau Bridge and Kap Shui Mun Bridge. They are the other two bridges listed in the world's "Three Mosts" as well. Visitors can also have a different spot at the Airport Core Programme Exhibition Centre located about 2 km north of the Bridge.