18 - Electric locomotives. The "Cocodrilo"

The “Cocodrilo” belongs to the first generation of electric locomotives. It is from Switzerland, a mountainous country in which electric engines were quickly adopted. These locomotives radically improved the railway’s energy consumption. In fact, when going downhill they return part of their energy to the network, apart from being quicker and more silent than steam and diesel engines. They need less maintenance, double the load capacity and have more features. Being a lot easier and cleaner to drive than steam locomotives, their appearance was a real revolution for drivers. The disadvantage is that it is very expensive to electrify railway lines. However, the present and future of the railway is linked to electricity: the fastest trains in the world are all electric.

The locomotive’s nickname appears to come from its peculiar shape. This series of engines was built in the late 1920s and was purchased by the North Company after deciding to electrify the line between Alsasua and Irún, which had a lot of freight and passenger traffic. Later on, they reached as far as Miranda de Ebro and Burgos. They were built to operate at 1,500 volts, which was how the first electrifications were designed. In the mid-20th century, a plan was approved to electrify all of Renfe’s main lines, while raising the voltage to 3,000 V, which enabled more powerful locomotives to be built. The plan was initially implemented in Catalonia. Their withdrawal began in 1967, with the appearance of dual-voltage locomotives (1,500 and 3,000 V), and concluded in 1976.