Overview
dRMM was commissioned by the London Design Festival (LDF) to create a piece of architectural sculpture in collaboration with The American Hardwood Export Council.
Endless Stair took inspiration from the structural, social and artistic possibilities of the staircase, the aspect of architecture most closely associated with sculpture and a place where people inevitably cross paths. Devised with M.C. Escher’s popular drawings in mind, Endless Stair is not a stair without end, but a stair designed to be endlessly reconfigured: an entirely prefabricated construction, each piece an essential part of the additive structure, where loads are transferred through demountable flights that can be recycled on another site in a different configuration. Endless Stair also took inspiration from the wood from which it was constructed and gave rise to an entirely new product using Tulip Tree wood as a cross-laminated timber (CLT) for the first time, with an extraordinary strength-to-weight ratio.
Endless Stair was deemed a huge success by the LDF, its sponsors and the many thousands of people who climbed its steps. Endless Stair forms part of dRMM’s pioneering timber portfolio and presents a case for engineered timber as the key construction material of the 21st century.
Structure
Endless Stair served as a vehicle for exploring structural and sculptural possibilities of tulipwood, donated by the American Hardwood Export Council, who were closely involved in the research and design process. The whole team worked collaboratively to overcome the challenges and complexities of the project. The University of Trento was central to understanding the essential rolling shear properties of the CLT, whilst the adhesive manufacturers helped specify the right type of glue to meet the manufacturing constraints and external use of the panels.
An early decision was to make the steps and balustrades on one side from identical connected pieces, equivalent in size. These are stacked up with a spacer element between them, creating the flights which, as a result of the stacking process, can step either to the right or to the left. Within this prefabricated construction, each piece is an essential part of the additive structure, indispensable within the load transfer path. Endless Stair is a fast and dry construction, easily demountable, and able to be entirely recycled on another site.
The knowledge and experience gained from this project can inform the debate on higher performance timber structural design, and the mainstreaming of hardwoods as an efficient engineered timber material.
