Somethinging, by California-based artist Pae White, is a large suspended sculpture made of 1,232 folded aluminium plates connected by 8,040 rivets, forming two dragonfly wings. Developed during the pandemic to evoke movement, lightness, and conviviality, it is the artist's first public realm commission in London - rising four storeys outside Renzo Piano Building Workshop's Cube building, above a Bakerloo Line entrance.
The artwork required innovative engineering to provide invisible support in a tightly constrained, windy site. Our solution uses just nine vertical rods, eight of which were tensioned against a hidden net of horizontally inclined rods connected into the building's existing slab edges. This replaced an earlier scheme of over 44 cables - which included a central column or enclosing glass box - with our structural solution keeping the artwork visually unobstructed.
Design and coordination were carried out largely in Rhino. Grasshopper, and Kangaroo, its physics engine, were used to find the right balance of prestress across the rods - keeping the vertical rods aligned and the inclined rods clear of the building's bulkheads. These results were validated in a non-linear finite element model in Oasys GSA, with wind loads from tunnel testing applied parametrically via the Grasshopper-GSA link. The same workflow let the model be updated quickly on site whenever anchor positions shifted.
The connections to the RPBW building were also carefully thought through to minimise material and using structural engineering to justify their simplified forms, following the direction and amplitude of the forces.
During installation, the rods were prestressed by hand, with strain gauges tracking force in real time. The measured prestress came within 10% of the calculated target - an unusually direct way to verify the design against reality, and a reminder of how rarely structural engineering gets to see its calculations proven in real time.
