The first tender covers project management and technical support services, with tendering for the civil works contract due to begin before the end of November. The government has decided not tender the electrical and mechanical element of the project and this work will be carried out by Alstom, which supplied and installed electrification and CBTC on the initial phase of the line.
The Pesos 7bn ($US 520m) extension will include one intermediate station serving the district of Álvaro Obregón. The project is due to be completed at the end of 2016.
The initial 25.1km phase of Line 12 from Mixcoac to Tláhuac opened in October 2012, but the section between Culhuacán and Tláhuac has been closed since March this year following the discovery of serious infrastructure defects and excessive wheel wear on the fleet of CAF trains.
An independent technical study carried out by TSO and Systra was completed at the beginning of September and recommended 32 corrective actions, including the replacement of 15km of track, 12,500 sleepers, 26 switch and crossing blades, and alteration of the angle of superelevation in curves. It also suggested reprofiling wheels on the train fleet.
The government has said it will initially cover the cost of any remedial work pending a final decision over which party is liable.