Castle Moat Bridge Concept Design

The world’s first pedestrian bridge with an intelligent composite system of wood and Plexiglas® was built in the heart of Darmstadt. It was considered a temporary model building for research purposes. Located directly on the bell building of the residential palace, the bridge spanned the eastern castle moat without significantly affecting the region’s landmark building.

Due to the combination of materials, the structure appears light and predominantly transparent. In addition, this combination is statically very efficient due to the stiffness ratio of the materials. With this new type of structural system, the external wooden straps absorb the tensile and compressive forces. The PMMA (Polymethylmethacrylate) discs act as webs to keep the upper and lower chords at a distance and form a thrust connection.

In close cooperation with the monument preservation authorities, a bridge structure was constructed, which rested freely on two pairs of supports in the moat. Separated from the existing castle by a gap, the bridge did not introduce any loads into the existing castle.

The reversible composite beam made of the renewable raw material wood and the completely recyclable material PMMA could be disassembled into its individual parts after the test phase and reused.