Bridge specialists Knight Architects and leading structural engineers WSP Finland have won an open design competition for a 3km-long bridge in Helsinki. The Anglo-Finnish team was one of ten to reach the shortlist following more than 50 entries when the competition was launched in 2011.

Organised by The City of Helsinki, the Kruunusillat (Crown Bridges) design competition was established to link the new waterside community of Kruunuvuorenranta directly to the heart of Helsinki and create a long-lasting structure synonymous with the city. The bridge will be used by trams, cyclists and pedestrians and the crossing will be the longest bridge structure in Finland.

WSP Finland and Knight Architects’ entry, titled ‘Gemma Regalis’, is a symmetrical cable-stayed bridge featuring a distinctive central 135m-tall pylon in the shape of a tall slender diamond, a reference to the historic crown ownership of the bay area, and whose multi-faceted surfaces have been designed to catch light and shadow by day and night. Equally recognisable in silhouette, the unique pylon forms a dynamic relationship with the two other tall landmarks in the capital city, the distinctive dome of Helsinki Cathedral and the tower of the Hanasaari power station, and supports two 250m spans which offer wide clear views of the low-lying coastal landscape at water level. A logical and proven structural form, the design minimises the cost and environmental impact of multiple supports in the water and the support piers to the approach spans adopt a ‘V’ shape, to complement the pylon and minimise their visual impact.

On deck, the cable-stayed form creates a strong nautical reference to sailing boats and the twin planes of cables create a comfortable and reassuring sense of enclosure over the central length of the crossing.