Grubenmann

Several members of the Swiss family Grubenmann were famous as joiners and civil engineers in the eighteenth century. The sons were innovators in bridge construction.

Ulrich Grubenmann (1668 - June 27, 1736) lived all his life in Gstalden, Appenzell Ausserrhoden where he fathered three sons:
*Jakob Grubenmann (January 10, 1694 - October 5, 1758), died in Hombrechtikon, Zürich;
*Johannes Grubenmann (June 15, 1707 - June 10, 1771), died in Teufen; and
*Hans Ulrich Grubenmann (March 23, 1709 - January 22, 1783), died in Teufen.

The brothers were village carpenters in Teufen. The principal structures are known to be:
*Crossing of the Rhine at Schaffhausen in two spans of 52 m and 59 m respectively, (Hans Ulrich, 1757);
*A single-span of 67 m at Reichenau, (Johannes, 1757);
*Crossing of the Limmat at Wettingen, a 60 m span thought to be the first use of a true arch in a timber bridge, (Hans Ulrich and Johannes, 1778).

Very few of their bridges have survived, those at Schaffhausen and Wettingen being burnt by the French in the , but their designs were influential, making use of novel combinations of arches and trusses. The surviving bridges include:
*Rümlangbrücke, Oberglatt, 27.5 m span
*Hundwilertobel, 30 m span
*Kubelbrücke, Herisau, 30 m span

Bibliography

*de Mechel, Chrétien "Plans, coupes et élévations des trois points de bois le plus remarquables de la Suisse"
*"John Soane and the Wooden Bridges of Switzerland: Architecture and the Culture of Technology from Palladio to Grubenmanns", catalogue of an exhibition at Sir John Soane's Museum, ISBN 88-87624-24-0
*Timoshenko, S. P. (1953) "History of Strength of Materials", pp182-183, ISBN 0-486-61187-6
*Troyano, L. F. (2003) "Bridge Engineering - A Global Perspective", pp158-159, ISBN 0-7277-3215-3