Lantau Link in Hong Kong
As the Hong Kong Government’s consultant, Mott MacDonald conceived, planned, designed and managed the £780m Lantau Link through all stages of the project including - feasibility and strategic planning studies, design, contract documentation, construction management and site supervision.

Lantau Link is a vital connection in the road and rail transport network joining Hong Kong’s commercial heart with the new international airport at Chek Lap Kok on Lantau Island. It is formed by two bridges — Tsing Ma suspension bridge crossing the main Ma Wan shipping channel between Tsing Yi and Ma Wan islands plus the Kap Shui Mun cable-stayed bridge, which traverses the waterway between Ma Wan and Lantau. The bridges are linked by a high level viaduct across Ma Wan Island. Both the 1,377m main span Tsing Ma Bridge and the 430m main span Kap Shui Mun Bridge carry a six-lane highway on their top decks and twin rail tracks plus two emergency road lanes on their sheltered lower levels, making them the largest bridges of their kind in the world and the first to provide a truly all-weather crossing, even in typhoon winds.

As the Hong Kong Government’s consultant, Mott MacDonald conceived, planned, designed and managed the Lantau Link through all stages of the project. We were responsible for all design of the £600 million Tsing Ma Bridge, concept, design and specification of the £180 million Kap Shui Mun Bridge, and construction management of the whole project. The entire project was completed on time and within budget only eight years after the decision to site Hong Kong’s much-needed replacement airport at Lantau.

Between the go-ahead in late 1989 and the start of construction in May 1992, Mott MacDonald produced the design, advised the government on how to procure the link and prepared the contract documentation which later formed the model for the majority of the Airport Core Programme project. Contract management and site supervision duties also included overseeing component manufacture in countries including Dubai, Japan, China, Australia and Britain. Mott MacDonald’s project team — over 300-strong at its peak — included bridge engineers, technical and contractual specialists, safety experts, technical inspectors, surveyors, project programmers and controllers, environmental specialists and quality managers. Mott MacDonald’s specialist inspection division was responsible for inspecting structural steelwork, cable wire and mechanical and electrical equipment manufactured in Britain, Germany, Denmark, Italy, Luxembourg and Switzerland.

Mott MacDonald’s involvement in the Lantau Link began in 1978 with a feasibility study into connecting Lantau Island with the mainland, followed by a design for a crossing in 1980. This scheme was updated as a result of the Port and Airport Development Strategy (PADS) study led by Mott MacDonald, which established the blueprint for the new airport and its associated infrastructure. This required a crossing to Lantau Island, differing in some aspects from earlier schemes and carrying a dual three-lane highway plus a high-speed railway. The firm reviewed various alternatives for location and structural form before choosing a final alignment resulting in a main span of 1,377m for Tsing Ma Bridge.

Tsing Ma Bridge — which crosses the strategic shipping route to China — is the centrepiece of Lantau Link, a vital connection in the transport system serving Hong Kong’s new airport on Lantau Island. As such it has to remain open to road traffic and the 135km/h airport railway during the region’s severe tropical storms when winds can gust at up to 290km/h.

To satisfy structural and safety criteria we developed a highly compact vented two-level steel deck, 41m wide and only 7.7m deep, with stainless steel aerodynamic fairings. Extensive wind tunnel tests were undertaken on model deck sections to confirm the efficiency of this section in all weather conditions. To meet stringent ride performance criteria for the railway Mott MacDonald designed an innovative trackform comprising a complex steel grillage on resilient bearings to optimise dynamic characteristics while minimising weight and vibration. The railway also features the world’s biggest rail movement joint to accommodate up to 1 m of contraction and expansion by the 2km long bridge deck and we directed and supervised the design and manufacture of this £10 million joint.