The magnetically levitated (maglev) train linking China's Shanghai International Airport and the city's financial district, reaches a top speed of 431 km/h (267.8 mph) on each 30 km (18 mile) run. The train, built by Germany's Transrapid International, had its official maiden run on 31 December 2002. Maglev trains use the power of electromagnetism to levitate the carriages above the guideways, meaning that there is effectively no contact (and friction) between train and track. The train makes the 30 km (18 mile) journey in just 8 minutes, a trip that can take up to an hour in a taxi. The train was built in under two years using technology supplied by the Transrapid consortium (consisting of Siemens and ThyssenKrupp). The train is claimed to have a top speed of 500 km/h (310.6 mph) under test conditions, but in this instance it is limited by the route length, distance between stops an other factors. Consultant notes: Because of the limited length of the track and the time taken to accelerate and decelerate, the average journey speed for this trip is 225 km/h (139.8 mph). This means that it is not the fastest train journey based on average speed -see record ID 43832.