Swiss Locomotive and Machine Works was a railway equipment manufacturer based in Winterthur in Switzerland. Much of the world's mountain railway equipment was constructed by the company.

Winterthur is a city in the canton of Zürich in northern Switzerland. With over 110,000 residents, it is the country's sixth-largest city by population, as well as its ninth-largest agglomeration with about 140,000 inhabitants. Located about 20 kilometres (12 mi) northeast of Zürich, Winterthur is a service and high-tech industrial satellite city within Greater Zürich.