Line C (Buenos Aires Underground)
Line C of the Buenos Aires Underground, that runs from Retiro to Constitución terminus, opened on 9 November 1934, and it has a length of . It runs under such streets as Lima Sur, Bernardo de Irigoyen, Carlos Pellegrini, Esmeralda, la Plaza San Martín and Avenida Ramos Mejia. It not only connects to every other line on the system (with the exception of Line H, which will be connected at a later date), but its termini at Retiro and Constitución also connect it to some of the most important commuter rail networks in Buenos Aires, such  as the Mitre and Roca lines and also long-distance passenger services. It is thus an important artery in Buenos Aires' transport system. At the same time, it is also the shortest line in both terms of length and number of stations. It was the third line of the network to provide service to the public, after Line A and Line B. Up until 2007 with the opening of line H, it was the only line in the system providing a north–south service. History. The line was constructed by the Compañía Hispano Argentina de Obras Públicas y Finanzas (CHADOPyF , Hispanic-Argentine Company for Public Works and Finances), headed by a Spanish nobleman, Rafael Benjumea, the Count of Guadalhorce, after the Great Depression of the 1930s had meant the Anglo-Argentine Tramways Company (which owned most of the then-vast tram network in the city) pulled out of its construction. The line was subsequently opened in 1934 and extended from the present terminus at Constitución to Diagonal Norte in the centre of the city. The stretch from Diagonal Norte to its present terminus at Retiro was then opened in 1936 and marked the last expansion of the line, which remains  the only line not to be extended since then. On opening, the stations were decorated with murals depicting rural Spain created by Argentine artists Martín S. Noel and Manuel Escasani, as well as some stations taking Moorish influences and were painted with gold powder. It had advanced technology for the time, such as Automatic Train Stop (ATS). When Line E was opened in 1938, its original terminus was shared with that of Line C at Constitución, however the route of Line E was altered in 1966 for the lines to meet instead at Independencia, where they still do so to  this day. With the current extension of Line E and Line H, they will both meet Line C at Retiro, where all three will terminate. Siemens are currently modernising the signalling systems on the line, at a cost of $18 million which includes the use of Communications-based train control (CBTC) in order to improve the line's frequency and potentially open up the possibility of automatic trains in the future. The work is expected to be completed towards the end of 2016. Aside from the signalling system, the line will is also having its stations refurbished, its rolling  stock refurbished and ventilation improved, in part to compensate from the extra heat associated with the air conditioning units added to the trains. Major works are also under way at Constitución railway station to provide better transfers between the Roca Line, Line C and Metrobus Sur in the area, which includes the construction of a new underground annex to the station. Large segments of track, as well as switches, are also being replaced. Rolling stock. When the line was first opened, it was served by Siemens-Schuckert Orenstein & Koppel rolling stock in its entirety until 2007. In 1999, trains were  purchased from the Nagoya Municipal Subway but they ultimately ended up serving Line D, and were then sent to Line C in 2007 as Line D acquired more new Alstom rolling stock and Line H was opened, meaning that the Siemens O&K trains were needed there as temporary stock until newer Alstom Metropolis trains arrived there. In 2015, refurbished Nagoya Municipal Subway 5000 series rolling stock began to arrive, adding 50% capacity to the line's existing Nagoya trains and reducing journey times. Though the rolling stock is in very good condition and will be further refurbished, the purchase was  criticised by the Minister of the Interior and Transport, Florencio Randazzo, who accused the Municipal Government of buying dated rolling stock in contrast to the brand new rolling stock purchased by the Ministry for Buenos Aires' commuter rail network and Line A of the underground. Along with the purchase, the existing Nagoya rolling stock will also be refurbished with air conditioning.