A sail structure in the form of a butterfly
The south-facing conservatory is shaded by a sail structure;a series of overlapping fan-shaped sails that flare out like the wings of a butterfly at each side of a delicate stainless-steel structure supported on four insectile legs. The sails are translucent and overlaid with translucent coloured film in abstract patterns, which are projected onto the floor of the conservatory when the sun shines The sails are made of translucent laminated polyester film reinforced with high modulus Twaron and Spectra aramid fibre. The coloured translucent overlay is a UV-resistant 3M film usually used for signs on glass shopfronts.
The sails are connected to cables and pulleys - using yacht technology - which allow them to be furled or unfurled as required. The fan shape of each sail is reinforced with glass-fibre ribs so that it keeps its shape in the open position and folds into pleats when furled. (In the drawing, the winching cables have been omitted for clarity. ) The stainless-steel structure supports two masts, which extend 8m to east and west, and two tapered 'ladder' beams - paired steel flats with CHS spacers - which slope upwards to north and south.
The sails are connected to the masts and ladder beams, which in turn have smaller ladder beams welded to them to raise one set of sails above the other. The structure is braced by a series of 10mm stranded wire cables with swaged forks and rapidlink connectors; they are connected together and propped by two spigots.
The highest sails are connected to a pair of masts; the lower parts of the masts are glass-fibre windsurfing masts and the upper parts are glass-fibre fishing rods.