Hong Kong Airport Rail Link, China

Massive growth in Hong Kong's importance as a trade and business centre has brought many problems for the island's existing infrastructure. This, in turn, has slowed down the rate of potential growth, at a time when the territory was keen to exploit its position as a force on the world trading scene.

It was therefore seen as vital that the territory had modern transport facilities, and the centrepiece of the development of these has been the new Chek Lap Kok international airport.

AIRPORT RAILWAY

The new 34km Airport Railway, opened in July 1998, is used by two distinct services. The Airport Express Line offers a fast passenger link between Chek Lap Kok and central Hong Kong. Journeys take 23mins, with intermediate stops at Kowloon and Tsing Yi, and are served by seven-car trains, offering an all-seated, business class-type service.

The Lantau Line offers a more rapid transit orientated service, linking Lantau, West Kowloon and Hong Kong Central. This serves six stations: Hong Kong, Kowloon, Tai Kok Tsui, Lai King, Tsing Yi and Tung Chung. An interchange with the MTR (Mass Transit Railway light rail system) is provided at Lai King. The introduction of this service has brought two major benefits to the territory: traffic on the busy Nathan Road Corridor of the MTR has been eased, while journey times between Lai King and Hong Kong Central have been slashed from 23mins to just 8½mins.

HONG KONG'S RAIL SYSTEMS

Hong Kong has five different rail systems: the heavily-used MTR network, the busy suburban Kowloon Canton Railway, the modern light transit (LRT) system, a traditional street tramway and the Peak funicular railway. Each operates independently, but there is considerable interchange between them.

Standard gauge lines are electrified at 1.5kV dc overhead, which gives total compatability with the MTR system. Train speed, a maximum of 135km/h (80mph), is considerably better than the 80km/h (50mph) which is the norm on MTR.

There are five intermediate stations on the two lines, some of which have separate, segregated platforms for Airport Express and Lantau Line services. 8km of the new line is in tunnel, including an immersed tube under Victoria Harbour and a total of 6km (4 miles) is carried on elevated sections. This includes the spectacular Tsing Ma suspension bridge, one of the territory's biggest engineering projects of recent years. One of the world's longest suspension bridges, it has a central span of 1,377m, one of the longest single spans of any bridge in the world. Built by Anglo-Japanese Construction, a consortium led by Trafalgar House, and including British contractor Costain Engineering & Construction, and Mitsui & Co of Japan.

With much of the line built on reclaimed land, the standard ballasted track can be shored up with additional material if required. However, tunnel, bridges and viaduct sections incorporate non-ballasted track on a concrete base, and in areas sensitive to noise pollution, floating slab track is used, to cut noise and vibration.

The high frequency of services along the Airport Railway and Lantau Lines places particularly heavy demands on its infrastructure. A British company is playing a prominent role in ensuring that the line is kept in as good a running order as possible. AEA Technology Rail, based in Derby, UK, has a £100,000 deal to create a computer model for the maintenance of the track geometry, which will study the ballast along the 35km line, assess how it behaves in daily use, and automatically develop a maintenance plan for the future. Another British connection exists in the train washing system supplied by BWI Dawson of West Yorkshire for the rolling stock serving both lines.

ROLLING STOCK

The contract for new trains to operate the services stipulated two distinct types of rolling stock for each service. However, the trains share a common aluminium-construction body design. They are built by joint partners Adtranz-CAF, the former supplying traction and control equipment and a cab simulator for training purposes. The latter the car bodies, bogies, interior fittings, air conditioning and auxiliary equipment. The trains were assembled in Spain, where static testing was also carried out, while final acceptance took place in Hong Kong.

The Airport Express Line is served by a fleet of eleven, seven-car trains whose facilities include a baggage car to carry luggage checked in at Hong Kong Central or Kowloon stations. They also have two-plus-two upholstered seats - 64 to each car - carpets, and luggage racks. Seat-back television screens provide up-to-date information on flights, MTR services and tourist information.

The Lantau Line's fleet comprises twelve trains, each of seven cars, seating a total of 336 passengers and with standing room for 264 more in each car - important given the anticipated heavy use to which they were expected to be subjected.

SIGNALLING/COMMUNICATIONS

Signalling comprises three fully-integrated system packages. Trains are supervised automatically from a main control centre, while their movements are controlled and constantly monitored by a transmission-based automatic train control system and computer-controlled interlocking.

Stations are fitted with state-of-the-art communication and monitoring systems, including integrated passenger information displays (linked with those on the Airport Express trains), to provide up-to-the-minute travel information on which details of any disruption to services can be displayed. Train drivers have two-way communication with their main control centre in the event of emergencies.

Easy-to-use ticket machines and automatic fare collection equipment has also been sourced from the UK. Passengers use touch-screens overlaid on a colour display to select their tickets, and payment is by notes, coins or credit card.

The machines are linked via the ethernet to the main station accounting system, with each one configured for its location by downloaded software. So, for example, the machines at Chek Lap Kok airport station only allow travel to any other AEL station, while the machines at all other stations are configured to assume that the destination is the airport.

When fully operational, with the anticipated strengthening of the new trains, the Airport Express link and Lantau line are expected to carry around 250,000 passengers a day.

In order to cater for this anticipated growth, the trains are capable of being strengthened from seven to ten cars, boosting capacity by around 50%. The signalling system is capable of handling a greater service frequency than the initial 8min interval. Ultimately, this could be increased to one train every 4½mins.