This was the 2 km section between the Plaza de los Virreyes metro station and Ana Maria Janer,[1] near the line's carhouse.

A contract for the latter was awarded around the end of 1985 to a consortium led by the Argentine company Materfer (Fábrica de Material Ferroviario),[5] of Córdoba, some of which were for a planned second line that was to be built later.

In order to avoid a long delay in the opening of the line, officials decided to create a temporary fleet by converting some 1913 metro cars into trams.

A total of eight such cars were built, using new metal bodies manufactured in Buenos Aires by EMEPA S.A., mounted on the original 1913 Belgian-built La Brugeoise underframes.

The low-platform stops along the line are long enough to accommodate only one car at a time, and multiple-unit operation is not planned, so the tramcars are not equipped with couplers.

[7] The original PreMetro plan developed in the late 1980s included the building of two or three more additional lines, however due to the timing of these projects having coincided with railway privatisation in Argentina, only PreMetro E2 materialised before the Buenos Aires Underground network was privatised and investment ground to a halt for the following two decades.

[10] The current extension of Line E northwards to Retiro replaced this,[11] but not the Puerto Madero section, which was briefly covered by the experimental Tranvia del Este.

[12] In July of 2024, SBASE launched a tender to connect the terminal stations of Centro Cívico Lugano and General Savio to unify the two branches of the system into a single loop.

[1] The carhouse (maintenance facility) for the line is located along Avenida Mariano Acosta, adjacent to the Somellera stop.