Old Mountain Line - Dahan Creek Railway Bridge Introduction
The "Old Mountain Line - Da'an River Bridge" is located at the junction of Taichung and Miaoli, adjacent to the southern entrance of Tunnel No. 7 in Sanyi Township, Miaoli County, and between the Houli District of Taichung City. It measures 637.39 meters in length and consists of 8 trusses made up of 10 spans totaling 62.41 meters each (one span between two piers constitutes one section). The Da'an River Bridge was constructed in the 36th year of the Meiji era (1903) and completed in the 41st year (1908). It was an important bridge for transporting goods and connecting the north and south during the Japanese colonial period. The Da'an River Bridge was renovated after the 1935 Central Taiwan earthquake in the 10th year of the Showa era(1935). In the 52nd year of the Republic (1963), structural reinforcements were made to accommodate heavier, faster, and more frequent trains, involving the replacement of steel beams. Although the new structure is not the original, its appearance remains similar to the initial construction, with slight differences in the trusses and joints. After the old mountain line was suspended in the 87th year of the Republic (1998), no trains have run over the Da'an River Bridge. Currently, among the old mountain line, only three iron bridges with this type of steel bridge structure remain: the "Da'an River Bridge" (637.39 meters), the "Dajia River Bridge" (382.2 meters), and the "Gaoping River Old Iron Bridge" (1,526 meters). Due to the well-preserved condition of the Da'an River Bridge, the "Old Mountain Line Old Photo Digitization Project - Potential World Heritage Site of Taiwan" was conducted in the 93rd year of the Republic (2004). After reorganizing in the 99th year of the Republic (2010), it was paired with the revival of steam trains on the old mountain line. In the 105th year of the Republic (2016), the "Investigation and Study of the Cultural Landscape of Taiwan's Old Mountain Line Railways and Preservation and Management Principles Project" was executed. Currently, it is managed for visitor safety and is closed to the public.
