The photo shows an un-manned train to transport passengers within the new terminal building at Beijing Capital International Airport.[Photo: China.com.cn] June 13 - The Mass Rapid Transit System, or MRT has begun a trail operation at Beijing Capital International Airport's new terminal building 3 on Tuesday.China.com.cn reports that the airport has purchased 11 un-manned small trains to transport passengers within the new terminal building.According to Beijing Construction Engineering Group, automatic safety doors will be installed at each platform station along the transit line. A train will arrive at the different stations every three minutes.The trains are decorated mainly in red, white and yellow with a large Beijing Olympic Games emblem at the front.Each carriage of the train can carry at most 83 passengers, with four chairs included for elderly, disabled or pregnant passengers.Cameras are installed inside each carriage in case of emergency.China.com.cn also reports that the light railway project been built between Dongzhimen and the Capital Airport will adopt the same style of train.