China's first sky trains came off the assembly line in the city of Nanjing yesterday. China becomes the third country to master sky train technology, after Germany and Japan. The two compartments can hold more than 200 passengers. <br/><br/>When compared with subways and trams, sky trains have lower costs, better climbing and turning ability, and higher wind resistance. The construction period of sky trains is also much shorter than that of subways, lasting only three to five months for dozens of kilometers of rails.