The Tüfisteg pedestrian and bicycle bridge, Adliswil

The Tüfisteg pedestrian and bicycle bridge in Adliswil is getting on in years. Analyses showed that replacing the bridge would cost almost as much as renovating it. Today, a new bridge leads over the Sihl – with beech wood from the surrounding forests. Since 1932, the Tüfisteg has formed an important connecting route across the Sihl and is also part of the “Sihluferweg”, which is actively used by the people of Adliswil. The bridge from 1932 was already replaced by a new bridge in 1985. Now, 45 years later, this bridge has also reached its zenith. In a first step, the company Timbatec was commissioned to record the condition of the existing bridge. The analyses showed that the bridge would have to be comprehensively rehabilitated or replaced immediately. The city of Adliswil decided to build a new bridge in the same style. The bridge in Adliswil is the first bridge in Switzerland with a pure beech wood construction. The 45-meter-long truss structure was planned and executed entirely with beech wood from the region. For the highly loaded compression bars, packages of small bar cross-sections were assembled instead of the usual large cross-sections glued together. This allows for better structural and chemical wood protection. Because: The components can dry more easily and be better impregnated. The planning of an open bridge with beech wood requires precise planning of the construction as well as the construction process from the cutting of the logs to the finished bridge. The close cooperation of the planners with the sawmill, the impregnation plant and the good communication were the key to success.