The sculpture is a funicular timber gridshell whose form was derived using in-house computational techniques. Firstly, a compression shell was form-found to perfectly fill the small space and confined boundary conditions. Secondly a discretisation of this shell along stress and curvature networks was undertaken. The two conjugate networks were found to be almost identical allowing for both fabrication benefits and structural performance.
Each member in the shell is a laser cut flat piece of 6mm FSC sourced plywood with zero torsion along their lengths due to a principal curvature orientation. As the members are also aligned with the principal stress field the self-weight of the structure travels mostly in axial compression to the supports. The density of the member discretisation is kept constant allowing the self-weight to be similar to that of the continuous shell. Due to each member being a constant depth, efficient nesting of the elements on each sheet of plywood was a simple task, allowing for minimal material wastage during manufacture. Every node connection is also laser cut plywood, connecting adjoining members and transferring load using a single bolt. By locating nodes on the funicular form, the bending moment is virtually zero allowing for a small size and reduced material usage. Reference numbers are scorched onto the plywood to assist with assembly.
The ‘Funnel Sculpture’ is therefore designed for both structural and fabrication considerations simultaneously. The whole shell is able to be unbolted, flat packed and transported using only a medium sized car, meaning the sculpture will have a life beyond that of its existing home at the Ramboll London office entrance foyer.