A new main entrance stair for the New Walk Museum, Leicester. The helical form was inspired by ammonite fossils from the museum's brilliant collection of curiosities and was derived from the Fibonacci sequence.
The complex geometries and long unsupported spans made this a challenging structure for us to design. A "ladder" of welded steel beams has been concealed beneath the treads to provide most of the structural support, while the steel plate balustrade contributes additional stiffness to resist vibrations from foot traffic.
The resulting stair is a crisp, simple steel structure painted white, contrasted with warm curved oak treads echoing the cellular nature of the fossils.