Operations commence for Tianjin metro Line 3 in China October 3, 2012 | Asia Pacific News Line 3 of the Tianjin metro entered into service with the commencement of a trial run for passengers on October 1, 2012. The 29.7-km line runs from Gaoxinqu in the southwest to Xiaodian in the ... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password