Lighting in Design Q1 2024

Bridging the divide Architecture and lighting are blended in a seamless marriage with the redesign and unveiling of the Wits University Sibanye-Stillwater Innovation Bridge.

to reimagine the visual and architectural identity of the now recently renamed W its Sibanye-Stillwater Innovation Bridge; the first phase of a longer term initiative to reconceptualise this pedestrian connector. “ In contrast to the heaviness of the ex isting structure, our architectural team, in close collaboration with the client, conceptualised a light, ephemeral design for the edges of the bridge that initiates a contemporary visual dialogue between old and new, ” says O tten. T hroughout the evolution of this refurbishment lighting manufacturer R egent L ighting Solutions developed a brand-new lighting element to k eep up with the demands of this iconic movement. Starting with a basic, cardboard mock-up profile, fabricated to scale, ex periments were conducted with various light sources to determine the output on the light post, as well as the surrounding structures. “ R educing the bridge edges to their essential structural components, all new interventions were carefully check ed against weight-bearing capacity and located inside the ex isting structure so as not to encroach on the road reserve and minimise complex ities around safety – particularly in terms of work ing over a busy arterial motorway, ” says R egent. T he designers from R egent, along with the structural engineer from C alibre, were heavily involved to ensure that mounting method, fixture intervals, and weight distribution of the additional 3 6 6 light elements would not compromise the structural integrity. T he design is deceptively simple and attaches to the bridge structure discreetly, adds O tten. After various developments in shape output, manufacturing methods and finishing, a single vertical element was fabricated as a prototype for final testing before large-scale production could kick off. Within five weeks, the urban light elements were fabricated, assembled and installed, repeating down the length of both edges of the bridge, forming a semi-transparent, comb-lik e surface. E ach post is a triangular aluminium ex trusion that is 4 . 2 m in length, precisely laser cut and machined to achieve all the necessary

E very day, thousands of people walk back and forth across a 5 0 m-wide bridge that spans J ohannesburg’s N 1 highway and connects the Braamfontein E ast and W est C ampuses of the U niversity of the W itwatersrand ( W its) . Beneath this pedestrian deck , spread across six traffic lanes, an endless stream of vehicles rushes north and south on a relentlessly billboarded daily commute, an all too familiar visual assault on the G reater J ohannesburg motorist. Built in 1 9 8 9 , what was then k nown as the AMIC Deck was constructed from a reinforced concrete slab cast over a profiled metal deck. T he bridge is supported by steel trusses that span the bridge abutments, while the sides of the bridge are formed by large steel trusses that rise above the traversable surface of the bridge to form over-scaled balustrades. “ T he heavy masculine structure is an iconic presence on the highway, and it has long been heralded as a gateway into or out of J oburg, ” says C raig M cC lenaghan, who served as proj ect architect on the revamp proj ect. In preparation for the university’s upcoming centenary in 2 0 2 2 , a generous sponsorship by mining giant, Sibanye-Stillwater, enabled the university to appoint Kate Otten Architects (KOA)

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