Inspired by the idea of a coiled apple peel, the staircase consists of three levels of semi-circular half-landings which wrap around a central 16m long inclined steel column. The position of each half landing rotates and shifts on plan to suit the drift of the leaning column. Whilst the tubular column supports most of the vertical load, stability of the leaning structure is maintained by the flight connections at each floor. A full 3D structural analysis was carried out in order to assess forces and deformations. Strict deflection and vibration control were major considerations, as well as minimising loads on the floor structure. Accuracy of fabrication was critical.