Changchun Railway Vehicles
In early 2008, the BTSC ordered 12 new trains (12 sets of four cars) from Changchun Railway Vehicles (EMU B class) to cater for the then soon to open Wong Wian Yai extension of the Silom Line. Their design was modified to the existing BTS's Siemens Modular Metro. The new trains were delivered late and only began service the Silom Line in December 2010. This was some 18 months after the Wong Wian Yai and Krung Thonburi stations were opened in May 2009 during which time there was severe overcrowding on the Silom line.