This paper reviews key advances in understanding the hydrodynamics of the forming section of papermaking during the years 1950 to 2000. Over this period papermaking advanced from rather slow-speed Fourdrinier machines to modern high-speed twin-wire formers. The advances are described in the context of technical problems faced at the time to increase machine speeds and improve paper properties. The scientific work and advances in machine design contributed greatly to the marvel of modern papermaking, which now includes machines 10 m wide operating at speeds over 100 km/h.