As the train D401-D402 for Shatin to Central Link (SCL), which was independently developed and manufactured by CRRC Changchun Railway Vehicles Co., Ltd. (CRV), moved slowly out of the Song Wong Toi Station, Tuen Ma Line, the longest MTR line in HKSAR, was opened as a whole on June 27, 2021. 

The highlights of D401-D402’s design include increased passenger space made possible by adoption of three to four seats without separation, olive-shaped armrests and ergonomically designed hand straps made of soft materials. 

Since the first phase of Tuen Ma Line was opened on February 14, 2020, CRRC CRV has started to prepare for the opening of the whole line, with efforts made to optimize such systems as TMS, air conditioning, communication, auxiliary power supply and traction to improve the stability and safety of software, and meanwhile adopt adaptive rectifications on cab door partition, outer skirt board, passenger compartment lighting and air conditioning unit to improve the degree of riding comfort. To make all procedures ready, CRRC CRV’s three teams remained on duty at Hung Hom, Tai Wai and Pat Heung for indicator sign replacing and vehicle status checking on the eve of the opening of the whole line. 

Tuen Ma Line, 56km in length, is the longest MTR line in HKSAR, east to Wu Kai Sha and west to Tuen Mun, covering 27 stations from the east of New Territories (NT), Kowloon and NT North West. In addition to extending the existing railway network, Tuen Ma Line brings about efficient and convenient railway service to such areas as To Kwa Wan and Kowloon that were not covered by rail transit line before.