Abstract
The crossing of rivers in Katanga (Democratic Republic of Congo) by railway lines in the 1920s and 1930s gave Belgian engineers and contractors the opportunity to build record spans for railway bridges. The crossing of the Lualaba River at Bukama consists of four Vierendeel steel girders each with a 62 m span, which were the largest of their type at the time of their erection in 1925. The crossing of the Lualaba at Kongolo, built in 1937–1939, required a 495 m long reinforced concrete continuous beam bridge with 14 spans, the largest measuring 70 m. It was the first significant concrete beam bridge constructed with a travelling gantry supporting movable formwork. The crossing of the Lukaga River (1938–1939) is a three-span concrete bridge with the 70 m long central span built using the cantilever method, which makes this bridge the oldest of its type in the world. This paper highlights the landmark characteristics of these forgotten bridges.