Architecture / Global
On balance
Bridges connect us. We meet the architects and engineers using them to brand cities, draw tourists and, of course, bring people together.
Bridges have long bound our societies together. But in recent years their roles in our cities have changed – and, in their evolution, they’re completely reinvigorating the urban realm.
Pedestrians are being brought back to the riverfront via structures that double as engaging public spaces. Motorists are also enjoying the fruits of engineering improvements on crossings that are on a more magestic scale than ever.
Let us introduce you to the world’s best bridge-builders whose work is stretching across to these new horizons.
1.
Next Architects
The Netherlands
“Everyone here uses this bridge – literally everyone,” says Sohaib Rohali, a student ambling across the Melkwegbridge in the Amsterdam suburb of Purmerend. It’s a bright late-winter morning and the reflection of this pedestrian-and-cyclist bridge ripples dreamily across the canal beneath it. Up on the deck, though, it’s all go: bicycle bells ring, breaking the solemn silence of a legion of commuters marching above the water, while a dog and its owner excitedly race up the high arching “top bridge” to survey the scene below. “You can see the whole town from up there,” says Rohail, pointing to the dramatic second span that forms a fine architectural focal point in what, until recently, was the colourless edge of a Dutch commuter town.
“While the bridge was being built, I was visiting the site and overheard these grumpy old men telling each other how stupid it was,” says Michel Schreinemachers. He’s a founding partner of Next Architects, the Amsterdam studio behind this bridge and more innovative crossings from the Netherlands to China. Constructed during a Dutch economic slowdown in 2012 at a costly sum of €6m, Melkwegbridge’s daring design – a high arching walkway swooping over a winding cycle lane and footpath that folds into the banks to allow boats to pass through – was divisive. The architect’s idea that this bridge would help to create a whole new precinct seemed overly ambitious. But, almost seven years on, Next Architects’ masterplan for this area – and the bridge at the heart of it – has proved a huge success for Purmerend. It has enabled the building of a school and many multistorey housing developments on one formerly disused side of the bridge, which now benefits from effective public-transport links; on the other side is the town’s centre. Meanwhile, a café at a petrol station next to the bridge enjoys a roaring trade from those relaxing on the freshly landscaped waterfront.
“A bridge can be more than a literal crossing,” says Marijn Schenk, also a founding partner at Next Architects. “It can bring many pieces together to form a meeting place. This is true of the Melkwegbridge, where people go just to climb up it, see the city and spend some time there.” This project’s success, and the urbanistic approach towards its design, has helped Next Architects to build international momentum and secure more bridge commissions. Developers as far apart as China and Sacramento are now challenging the Dutch firm to build crossings that add value to cities by creating new urban spaces.
In 2016 the architects unveiled the Lucky Knot Bridge: a triple-span, topsy-turvy red steel structure, in Changsa, China. This labyrinthine fixture is enjoyed as a recreational park as much as it is used as a pedestrian link. The smart design behind the undulating concrete of Next Architects’ newest work – the recently completed Zalige Bridge on the outskirts of Dutch city Nijmegen – responds to the river itself. When the water reaches its highest level (as it does sporadically for a total of one to two weeks per year), the bridge is partially submerged. Not only does this prevent people from crossing the bridge, it also teaches them how much rivers can fluctuate.
Zalige Bridge’s ambition to bring people to the urban riverfront – and to prompt a conversation about the city’s relationship with the water – reflects the ongoing dialogue of which Next Architects is a part. “Cities, have often turned their back to the river,” says Schreinemachers. “From a historic perspective, it’s not a place that is seen as friendly.” He adds that, as urban rivers become cleaner, his firm’s work can help to foster closer ties between a city and its river. “As cities intensify and become more densified, these open spaces are only going to become more appealing.”
Genoa builds for the future:
Set on a thin 30km strip of land sandwiched between the Apennine Mountains and the Ligurian Sea, Genoa depends on jawdropping civil engineering to function as a modern city. The collapse of its massive Morandi Bridge last year left 43 dead.
The crossing branched dramatically over the River Polcevera and carried the a10 motorway, a vital link between France and the rest of Italy. At the time of its opening in 1967, Riccardo Morandi’s grand project represented a brave, prosperous new world in the heyday of the so-called Italian economic miracle. Many Genoese called it the “Ponte Brooklyn” in reference to its similarity to the famed structure that spans New York’s East River.
The incident not only left Genoa in a deep state of shock but also highlighted the city’s reliance on its big infrastructure, which is not always well maintained. It is still unclear where the ultimate responsibility for the disaster lies but, as investigations into the collapse continue, the Genoese are refusing to waste any time in planning a swift recovery for their damaged city.
Genoan architect Renzo Piano unveiled his plans for a new €202m bridge in December, saying that it was “his civic duty” to take on the project. Piano describes his design as “simple and parsimonious – but not trivial”. In homage to Genoa’s maritime traditions, his new bridge will feature an underbelly that resembles a ship’s bow and 43 sail-shaped lamps – one for every victim of the collapse. It’s a serious undertaking that will face considerable challenges. But a slimline tender process addressing the urgency of the situation has sped up the building. The new bridge, which will be built by local companies, is due to be completed before the end of 2019 – and could lead to a smarter way of developing new infrastructure in Italy, which is notoriously slow and bureaucratic.
Both blessed and cursed by its astounding landscape, Genoa is justifiably known as “La Superba”. Sadly decades of underinvestment have left the city congested but, perversely, remote. Piano’s sleek steel bridge – that will span the Polcevera Valley for more than a kilometre – could well be a metaphor for Genoa’s renewal But, leaving symbolism aside, the city desperately needs Piano’s plans to be realised on schedule and on budget. La Superba deserves nothing less.
2.
Tamina Bridge
St Gallen, Switzerland
While Switzerland’s southern canton of St Gallen is known for its baroque thermal baths, its new Tamina Bridge – an asymmetrical concrete structure named after the canyon it spans – is making a quiet pitch to become the region’s newest landmark. “As far back as I can remember I was always looking from my village of Pfäfers to the other side and saying that we needed a bridge,” says Ferdinand Riederer, the former president of the municipality. Locals call him the bridge’s “father” for his early and constant support for the idea. “We are a municipality of only 1,600 inhabitants,” he says. “Yet, until recently, we were greatly divided due to geography.”
One valley, one municipality – but two separate worlds. To travel from Pfäfers to Valens on the opposite side of the canyon, one had to weave up and down the valley – a journey taking at least half an hour. Despite this, many residents thought that the sanctity of untouched nature (Pfäfers neighbours a protected park) trumped the need for a shorter crossing. “Nature is something of national pride here,” says Riederer. It wasn’t until a report proved that the old landslide-prone road had become too dangerous to use that a decision to build this bridge was made. Other factors, including connecting two important medical centres and improving routes for firefighters, were also in play.
The new project, though, needed to meet the high standards required for building in Switzerland before any ground was broken. The massive structure would have to blend into the landscape. “The challenge was to devise a sleek bridge with no columns on the ground and little invasion to the surrounding valley, all while being more than 200 metres above the gorge,” says Holger Haug, manager of Stuttgart-headquartered engineering firm Leonhardt, Andrä und Partner, whose slender design was selected to rise to the task. “It truly took a great deal of innovation.”
In 2017 the opposite sides of the valley became two independent construction sites, both accommodating monstrous cranes brought in from Germany. The resulting bridge combines an elongated arch and flat upper surface, with the curves of the bridge mimicking the valley’s slopes. Its weight is anchored by four legs, the minimum required for such a heavy structure. Rather than using upright pillars, precisely placed tilted buttresses support the bridge without interfering with the view.
The result is modest and unobtrusive but this construction was so daring and delicate that some 400 international groups, including a Japanese media delegation, visited the site to observe this masterclass in Mitteleuropean engineering. “In 40 years of my career I have never seen something come even close to this,” says Ruedi Vögeli, the deputy at St Gallen’s Civil Engineering Office, recalling one of the build’s most precarious moments. “We were closing the arch from two ends of the canyon and not one centimetre could be out of line,” he says. Cranes towering 100 metres above held the arch intact using steel ropes as the last batch of concrete was poured from a bucket hoisted above the centre of the bridge. It was an incredible feat, particularly as the bridge was constructed during an unforgiving Alpine winter.
Today truck drivers and daytrippers speeding over the Tamina Bridge are more likely to be awestruck by the views beyond – but the bridge has certainly impressed the world’s architecture and engineering community. It has won numerous engineering prizes (and been shortlisted for others) and has even had praise heaped upon it by the steeliest of design critics: Swiss architect Peter Zumthor. Tamina is the latest zenith of Swiss bridge-building but Ferdinand Riederer – its “father” – believes that there is more success to come. “It will revitalise the region,” he says.
3.
Tilikum Crossing
Portland, Oregon
Portland has fine taste in bridges. At the confluence of two rivers, the Oregon city boasts 16 such structures, each delivering a distinct historical and architectural punch – and everyone has their favourite.
The St Johns Bridge vaults up against a woody backdrop, its emerald-green conical archways suggesting a Jazz Age take on a cathedral. The arching steel I-beams and double-decker car lanes of the Fremont (which opened in 1973 and was once the longest bridge of its kind) is testament to the US’s mid-century assuredness. The Steel, built in 1912, glowers beneath clambering twin towers of latticed black girders containing massive counterweights. These structures link Portland’s two halves and define a cityscape nicknamed Bridgetown.
“If you add a new bridge to Portland, it has to be state of the art,” says architect Donald MacDonald. “You also have to think about the next 100 years.” MacDonald knows the challenge all too well. In 2015, the San Francisco-based designer crafted the newest member of the city’s bridge family. Tilikum Crossing is a gently sloped concrete bridge, buttressed by triangular cable supports, that connects two burgeoning neighbourhoods. If each Portland bridge embodies its own time, Tilikum sends a message about the city’s future. Cars are absent: the bridge has been widely praised by environmentalists for servicing a railway line, trams, buses, pedestrians and cyclists instead.
The Tilikum’s location and design were aimed at fostering new urban density. “The purpose of the bridge is to stimulate development on both sides of the river,” says Bob Hastings, a real estate specialist from TriMet, the government agency that led the construction. “It’s there to unlock potential.” The bridge links previously disconnected cultural institutions on either bank of the Willamette River. Oregon Health Sciences University, the state’s largest medical school, has built major research buildings at its west end. “They aim to recruit world-class talent. Now they can point to the bridge and say, ‘This will be your view,’” says Hastings. Industrial land nearby awaits redevelopment; residential and retail buildings are also set to be built.
These lofty commercial and social ambitions presented architects with plenty of aesthetic, political and technical challenges. MacDonald, a veteran of dozens of bridge projects, joined the effort after initial proposed designs met resistance. “With a bridge, you can’t really personalise the architecture,” he says. “The design has to be civic – for the community.” He presented hand-drawn sketches at public hearings and informal meetings. “If you come with computer renderings, people think you’re trying to sell them something,” he says.
The resulting structure employs a cable-stay support system that allowed its towers to echo Mount Hood, the jagged volcanic peak on Portland’s eastern horizon. Artists devised a lighting scheme that responds to river conditions: warmer water brings on orange and red hues, for instance. Tilikum can withstand winds of up to 240km/h and a major earthquake, one at least as severe as the 1985 earthquake that struck Mexico City, killing at least 9,500.
Tilikum has become an icon in the city. “We’ve seen beers named after it and heard songs written about it,” says Hastings. “Television broadcasts use it as their backdrop.” The bridge’s name roughly means “the people” in Chinook, a common language used by the region’s indigenous tribes; native art and performance featured prominently at its dedication. Today locals and visitors alike treat this crossing as a destination.
On a recent blustery afternoon, Robert Coombs, a vice-president of the socially conscious Presidio Graduate School, walked both sides of the Tilikum. “It was on my sustainability bucket-list,” he says, referring to the cyclists and trams whirring past. “The physical infrastructure is interesting but the connections between creative communities, higher education, industry and craft are even more compelling.”
Green-minded Portland couldn’t have scripted it better.
