BRENNER RAILWAY BRIDGES: THE DIFFUSION OF HOWE TYPOLOGY IN AUSTRIAN EMPIRE. Chiara Tardini 1  Keywords: Theory and practice of construction history, Wilhelm von Pressel, Howe bridge typology, 19 th century, Austro-Hungarian Emperor Abstract This paper will focus on the wooden bridges drawing collection designed for the Puster valley railway line by Wilhelm von Pressel. Unpublished drawings both of timber and iron bridges made in 1867 are a sort of abacus that can be adopted as a guide in design. They represent one of the early executed projects of Howe typology in Austria. The dimensions of the width and depth of the transversal cross-section of the elements are given according to the span length; thus the design of a railway timber bridge is made easy. The bridges included in these collections adopted the same structural typology that was patented in U.S.A. by William Howe in 1840. This typology was spread in Europe by Carl von Ghega: after his study he had a trip to U.S.A. between 1842 and 1844. His treatise Über Nordamerikanischer Brückenbau und herechnung des tragungswermogens der Howe’schen brücken was absolutely essential for the spread of the Town, Long and Howe typologies in Europe since it is one of the early European engineering publications on the U.S. patented layout. The Puster valley railway line was designed by the German engineer Wilhelm von Pressel. In 1839 he travelled to France and England to study their railway line system; when he came back he devoted to the railway line construction. Initially, he built the Geislinger Steige (1844-1850), one of the first German mountain railway lines, working with the engineer Karl von Etzel; in 1853 he worked in Switzerland, where he successfully employed the English method in building the Hauenstein tunnel. In 1859 a new railway society was created: the k.k. priv. Südbahn-Gesellschaft, and between 1863 and 1864 the Villach-Maribor railway line was completed. In 1865 he was appointed chief director of the new railway society: the k.k. priv. Südbahn Gesellschaft. In this period he designed the Puster valley railway line, on which these remarkable timber and iron bridges were built. Starting from July 1869 three Bavarian companies (Hügel, Sager e Angermann) in about two years carried out the construction of the Puster valley railway line. In 1869 Pressel left the Südbahn society and was in charge in the Turkish railway society. He designed 6800 km of railway lines and worked at the very beginning of the Baghdād railway system. He wrote several books on railway design and technique. On November 1871 the Puster valley railway line was launched without any official ceremony: saved money were allocated to poor people. 1 Corresponding Author, Research Assistant, Politecnico di Milano, Italy, chiara.tardini@polimi.it