Design and Construction of the Printing Works at Debden

THE paper reviews the development of road bridges in Norway, mainly during the last 150 years. As an introduction local conditions and the oldest known types of bridges are briefly described, together with a survey of Norwegian administration of roads and bridges. Bridge types commonly used in the 19th century are briefly described, such as stone arches, various types of timber bridges, the first suspension bridges, cast iron arches and the first steel trusses. A more detailed review is given of the bridge types of the last 50 years, with special reference to the flexible suspension bridges introduced in 1927 by Chief Engineer 0. Stang. After mentioning the wholesale destruction of Norwegian bridges during the last war, a number of post-war bridges are described. As to prestressed concrete attention is drawn to the special conditions in Norway, such as the severe climate and the limited financial resources for experinental work. Amongst the bridges described are a composite welded plategirder with some temporary and some permanent prestressing cables, a recently finished steel arch of 603 ft. span and a two-span suspension bridge with openings of 1,100 and 463 ft. which is at present being erected. The paper concludes with a survey of Norwegian design loadings and common road widths, the number and loading capacity of existing public road bridges and the recent extent of road bridge construction. Arnulf Arild