Paris's original tram lines began operation in 1855 with horse-drawn lines. They were upgraded to steam, pneumatic engines, and finally, electricity, before the last of these lines was discontinued in 1938. The RATP began to build newer, modern tram lines towards the end of the 20th Century. The first of these lines opened in 1992. As of 2014, there are nine lines in operation, one of which is operated by the SNCF.