In the 1910s, electrification was already common on metros and tramways, but the low-voltage DC typically used was less suitable for main lines. ABB’s predecessor company, MFO, was one of the pioneers of the alternative: high-voltage single-phase AC – a solution that is the backbone of mainline electrification across the world today.

At the time, most railways used steam locomotives. As Switzerland’s reliance on imported locomotive coal had become a liability during the First Word War, it was decided in 1916 to electrify the Gotthard railway using hydro electricity, and order the crocodile locomotives to pull the trains. The steeply graded Gotthard line crosses the Alps by a series of elegant tunnels and bridges, climbing to a height of 1,151m in its 15km long summit tunnel. Until the recent completion of the Gotthard base tunnel, this link was a backbone of the continent’s railways, connecting the railways of northern and southern Europe, as well as being a benchmark for locomotive performance. 

The crocodile’s extended nose that protruded far in front of the cab, as well as its large wheels and coupling rods are reminiscent of steam locomotives. But underneath the hood, MFO had packed it with innovations, including a regenerative brake (when running downhill, electricity was fed back into the catenary).

As part of the Gotthard electrification, three hydro-electric power plants were built near the line at Amsteg, Ritom and Barberine – they are still generating today. The Gotthard had turned to clean and renewable energy long before it became fashionable.

The name “crocodile” was probably coined by the German model train manufacturer, Märklin, who carried the legend’s fame across the world. The Crocodile had become a symbol of Swiss precision and innovation.

The design’s success was soon followed by a narrow-gauge version for the Rhaetian Railway, with further variants appearing in Austra, Spain and India. In many cases, ABB’s predecessor companies were among the suppliers. The original SBB crocodiles began to be displaced from the Gotthard by faster and more powerful locomotives in the 1950s, but their rugged design and raw reliability ensured they had long service lives elsewhere on SBB’s network. The last one was not retired until 1986. Several examples have been retained by museums, some of them operational.

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