King Louis Bridge

The King Louis Bridge (German: König-Ludwig-Brücke) spans the River Iller in the town of Kempten in the Allgäu in southern Germany.

After being reconstructed and changed in use several times, the bridge is currently closed due to an assumed instability.

The construction was closed to trains in 1905, due to neighbouring concrete bridges (Obere Illerbrücken), which were almost finished.

The emerging gap was filled within the same year, using a wooden interim bridge, which was replaced by a composite construction in 1957.

After the construction of the new Kempten Station in 1969, one of the concrete bridges was closed to trains and altered for road traffic.

It is the only remaining bridge built according to the Howe truss structure and was the longest one of them in Germany,[1] presumably worldwide.

Over time the damage caused by the elements was so advanced, that the town decided to close the bridge for safety reasons in December 2013.

[8] The cross section of the wooden superstructure, two box-shaped constructions, which have respectively two girder supporting systems of 5,26 meters high and each one has an overhead and an underlying wind brace.

The struts have a square cross section with 19 centimeters edge length and are made of stone and are finished with Swiss larch beam and oil-soaked oak.

The whole wooden construction leans on two pillars nearly 25 meters high and on two counter bearings, which were built of stone with a revetment of ashlar.

[14] This revetment was weatherproof (rain, sun) and resistant to flying sparks and ashes of steam trains.

The carriers were wrapped in foil in a complex process to prevent further damage due to weather conditions.

Ever since its erection the bridge was planked, until 1986, when the timber panels, which blocked the sight of the truss-structure, were removed.