THE BUTTERFLY BRIDGE BEDFORD, UK
2. The Butterfly Bridge. A footbridge over the section of the river, next to the Embankment, which is used forrowing. The bridge was opened by Big Ears in 1998 after an architectural competition and was notoriously expensive. It was supposed to make a pontoon bridge used in the River Festival redundant and so pay for itself, but in fact itis used as well as, rather than instead of, the temporary bride. 3. The bridge, at 32m in span, has twin steel arches which are inclined like butterfly wings to produce afeeling of containment on the deck and, simultaneously, an openness to the sky. The deck extends onto the landscaped banks at each end to engage with the open space around thebridge and enable step-free access, with longitudinal deck lighting concealed at kicker level within theparapets.Date Completed : 1997Architect: Chris Wilkinson ArchitectsLocation : Bedford, UK Engineer: Jan Bobrowski and PartnersClient : Bedford Borough Council Contractor: Littlehampton Welding LtdValue : 375,000 4. The two inclined tubular steel arches form the primary structure from which the hardwoodtimber deck is suspended by means of a system of rod hangers connected to transverse steelbearers that are integral with the balusters supporting the handrails.The two curved tubes support the suspended steel and timber deck with stainless steel cables.The contract included the concrete abutments which required accurate setting-out of fixingbolts, in particular those restraining the curved tubes. 5. In the context of the multiple factors informing the design, the result is functional on manylevels. Its reason to be, a level and navigable crossing of the Great Ouse [in contrast to thesteeply sloped existing suspension bridge], is a by-product of the more esoteric demands of thedesign problem. Structurally the composition is at the limits of its capability. Visually it isintentionally arresting and historically it is anchored to its site by reference to the existing. Thedesign is a result of a collaborative application of art and engineering in contrast to Webstersengineering latterly perceived as art."