At the same time, high-profile accidents in Flores and Once in previous years had led the national government to revise the concession-based railway privatisation, which was largely blamed for the deterioration of the network.

[14] The units were built at CSR's Qingdao factory, a large complex with 1,640,000 m2 (17,652,813 sq ft) of covered space.

[15] In 2014, CSR then purchased the Argentine rolling stock manufacturer Emprendimientos Ferroviarios, in part to establish a place in Argentina to maintain the trains once they were in operation.

[16][17] The trains have a series of features in line with modern rolling stock, such as ABS, air conditioning, CCTV, a train protection system and intelligent doors, while numerous components such as the brakes and traction system were sourced from countries such as Germany, Sweden and Japan.

[18][19] The Roca Line trains have some differences: overhead collection at 25 000 V (instead of 800 V third rail), more (but smaller) windows per car, and no CCTV cameras.