In the last decade of the nineteenth century, the SCB needed more powerful freight locomotives. Since they had to be eight-coupled, but had to run through tight curves like those on the Hauenstein line, they were to be Mallets. The order for the new Ed 2x2/2 was placed with Maffei, which also had delivered the Ed 2x3/3 for the Gotthard Railway. So this was inspired by the Gotthard locomotive, but reduced in size to two two-axle groups. The first six were delivered in 1891 and two years later, ten more followed which were lighter, but had larger supplies of water and coal.

As with the Ed 2x3/3, it turned out that their boilers were too small. So the next Mallets delivered to the SCB by the SLM were tender locomotives of the type D 2x2/2, which had a larger boiler. Later the SBB rebuilt two Ed 2x2/2 with new boilers. Today only number 196 is still existing. It was withdrawn in 1938 and after it had resided in the Swiss Museum of Transport between 1959 and 1974, it is operational again since 1992 with the Oensingen Balsthal Railway.