MTR begins full-length trial operations on Tuen Ma Line; to install real-time track-monitoring system, Hong Kong February 12, 2021 | Asia Pacific News MTR Corporation (MTR) has commenced full-length trial operations on Tuen Ma Line, the longest rail line in Hong Kong. It spans 56 km and covers 27 stations. It also offers interchange facilities for m... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password