On the 27.01.2016 the Robbins TBM EPB operated by the JV Afcons-Transtonnelstroy broke through. This happened on the downline tunnel at Chennai’s Central station after tunnelling through 1025 meters under several buildings, the Cooum river and the Southern Railways’ tracks. The TBM was originally launched from the May Day Park shaft in February 2015.In total there were 732 rings installed on the line. Excavation will still need another month after which the TBM’s cutterhead & shields will be recovered. In the meantime, the TBM’s backup gantry will be disassembled and be taken out from its behind it via the May Day Park shaft. After this breakthrough there will be a further four in order to complete the UAA01 section between Egmore, May Day Park and Washermenpet. All four will take place at Central station – two from the Egmore station side and two from the High Court station side. Click here for the map and in/40 for tunnelbuilder archive. Visit http://chennaimetrorail.gov.in and http://www.therobbinscompany.com/. 05/16.