Arup has helped realise the strikingly beautiful ‘One Rock on top of Another Rock’ sculpture by the Swiss Artists Peter Fischli and the late David Weiss.
‘One Rock on top of Another Rock’ is Fischli’s first UK installation and was unveiled in Kensington Gardens, London’s Hyde Park on Friday 8 March.
The two rocks that form the sculpture are weathered granite boulders, each weighing just under 30 tonnes. These have been shaped by glacial action and natural weathering over thousands of years into magnificent and complex forms. The rocks are delicately and precisely balanced on top of each other, held together simply by gravity.
Working in close collaboration with The Serpentine Gallery and Peter Fischli, Arup made the installation possible by using state of the art LiDAR (Light Detection and Ranging) surveying technology on the rocks at their original location in North Wales. 3D printing technology was then used to produce exact physical models at one twentieth of the scale to explore different balanced configurations of the two rocks.
This unique opportunity has allowed Arup to demonstrate the simple engineering principles of balance and gravity. The trick has been to keep the centres of gravity of the rocks within the points of support. This is ultimately a high tech design process that enabled a low tech solution.The irregular geometry of the rocks creates an illusion that they are about to topple over, making it difficult for the human eye to judge intuitively where the centre of gravity of each rock is. However, the rocks are safely stacked on top of each other, with the sheer weight of the rocks meaning that they have an inherent sufficient resistance to being pushed over. Alice Blair, Lead Engineer, Arup
The simplicity of the final solution meant that it was possible to complete the installation in less than three hours.