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, and 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 11 seven-car trains whose facilities include a baggage car to carry luggage checked in at Hong Kong Central or Kowloon stations. The Lantau Line's fleet comprises 12 trains, also 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.
Train drivers have two-way communication with their main control centre in the event of emergencies.
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. The signalling system is capable of handling a greater service frequency than the initial eight minute interval.