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The Startup

Will This Stockholm Megaproject Be Digital Construction’s Moment of Truth?

‘We may look back and say Slussen finally convinced the industry to leave manual processes behind.’

Designing the new Slussen: from 15,000 hand-rendered drawings to nil

A buzz of creative chaos fills the air around Stockholm’s Slussen. The civil works mega-project is gutting the city centre’s decrepit, thirties-era transport node and replacing it with a people-friendly mix of waterside parks and modern infrastructure.

It’s loud and it’s busy; an endless rush of cars, humans, buses, and ferryboats streaming to & fro amid looming concrete foundations and the hammering of heavy equipment.

You’d be forgiven for thinking it all looks an unmanageable mess. But underneath the din, digital technology is helping orchestrate hundreds of designers, engineers, architects and builders as they complete the thousands of complex deliverables needed to see the seventeen-year project through to fruition.

When it’s done in 2025, they’ll have future-proofed Stockholm’s ageing weekday commuter nexus and opened it up for weekend leisure. Digitisation will have played a decisive role.

From bottlenecks to BIM

At SEK 12bn (USD 1.3bn), Slussen is one of Europe’s largest urban infrastructure schemes. It aims to transform a complex convergence of ground, sea, and commuter arteries covering 70,000 square metres to create a new urban quarter that’s pedestrian- and cycle-friendly.

Built next to a historic navigation lock linking the Baltic Sea with freshwater Lake Mälaren, Slussen sits in the middle of Stockholm’s famed archipelago. More than a decade into the project the area’s topography is undergoing dramatic change, starting with the replacement of a decaying multi-lane bridge and four-leaf-clover car interchange built in the 1930s.

Due to finish in 2025, the city-centre project is split into a lengthy list of discrete deliverables being designed and built alongside live construction work.

The transformation is about more than infrastructure; it’s also a highly-visible cultural initiative with nearby museums rubbing up against new pedestrian malls, parks, and other elements that will open up the area to more footfall.

Heavy scrutiny

But being in the public eye comes with challenges. The scope of the project and the area’s historic significance means every change is being watched closely by journalists, politicians, cultural critics and heritage groups.

Numerous architects and academics inside Sweden and out have weighed in with their opinions on the design — all adding to the pressures that are part & parcel of any major public works initiative.

At Slussen, however, you also have to factor in the area’s unique topography. A maze of roads, bridges, railways, waterways, sidewalks, cycle lanes and concrete subways converge like nerve ganglia around the old navigation lock. The result is a highly-compressed building site with multiple interwoven structures.

The city’s sustainability targets will push motor traffic at Slussen down from 60,000 journeys per-day to around 20,000, but climate change isn’t waiting to make its presence felt. A rise in extreme weather events means flooding around Lake Mälaren — Sweden’s third-largest — is happening more frequently. That threatens the sewage treatment facility at nearby Upsala, so expanded water evacuation measures at Slussen are an urgent part of the plan.

The new Slussen has to be ready for whatever mother nature throws at it. And then there are the scheme’s hundreds of contractors and sub-contractors — all working on different components of the build simultaneously, whose work needs to be coordinated and shared.

It all adds up to colossal complexity, with only a tiny margin for error.

‘The city now faces different infrastructure issues, and the objectives have changed,’ says Gustav Jarlöv, a partner at White Architects in Stockholm. ‘Rather than just accommodate more car journeys between north and south, the aim now is for Slussen to promote sustainable growth. We are creating an attractive place where people will want to visit and re-designing the site to make traffic flows more efficient.’

Achieving that objective in such a pressurised environment hasn’t been straightforward, he says.

‘Sometimes it’s hard to get everyone to pull in the same direction’ This is always an issue in big projects, but technology is helping make this easier to manage’.

How digital is making it all possible

In the past, multi-partner collaboration on a big civil works project would have been managed using hand-rendered drawings. The 1930s re-vamp of Slussen took more than 3,000, and it’s estimated that the current scheme would need close to 15,000 drawings to facilitate design coordination.

Instead, all of that has been replaced by 35 richly-detailed 3D renderings created with Autodesk technology by Jarlöv’s team at White, and lead engineering firm ELU.

The digital simulations enable the lead firm’s architects and engineers to share detailed, up-to-date information between hundreds of designers and contractors. The 3D models also provide clients at the City of Stockholm and other non-technical stakeholders with quick and immersive updates on the scheme’s progress.

Project chiefs say digital’s contribution has been vital to keeping everything on track.

‘Looking back on the last ten years I’m not sure how the project would have been possible without digitisation,’ says Dan Svensson, head of department and Slussen project lead at engineers ELU Konsult AB.

Given the complexities, he says, it was lucky timing that critical technological breakthroughs happened in BIM and digital modelling while Slussen was in its early stages.

‘It’s not only an infrastructure node, it’s an urban redevelopment project with shops, bridges, terminals, promenades, and parks all packed into a very compressed area. We don’t have any of the building references we’re used to here. Every square metre is unique in every sense.’

Is this the inflexion point?

Slussen’s novel characteristics make it the perfect testing ground for the latest advances in design and construction technology, Svensson adds. As a project leader, he knows the world is watching. With so much riding on the outcome, the decision to adopt paperless project management has to work out.

“Maybe we are going to look back and say this was the moment when the construction industry finally decided to ‘go digital,’” he adds.

For mass adoption to happen, however, Svensson also believes the digital technologies at work will need to become even more user friendly. Construction is a big tent, he says, with different comfort levels around computerisation. He’s seen resistance from some quarters and thinks the only way to overcome it will be more vendor investment in UX, and a cross-industry effort to help people upskill and adapt.

Will Slussen turn out to be construction’s digital moment? That’s one for historians. But it could well be a decisive moment when clients, contractors, and software vendors began to find common cause in making digital even easier to weave into construction’s daily workflow.

Project snapshot:

Slussen dates back to 1643 when a lock was built to separate freshwater Lake Mälaren from the Baltic Sea.

An extensive rebuild in 1935 saw the area covered by a curling road and bridge system that converged around a cylinder-shaped office building. The structure sat above an underground bus terminal and beside the big navigation locks that regulate shipping traffic between Slussen’s salt- and freshwater sides.

By the mid-2000s the foundations were sinking, and the structure had become badly eroded. The City of Stockholm decided to demolish and rebuild — creating an opportunity to re-imagine the entire area.

Helmed by Foster + Partners, with White Architects overseeing landscape architecture and ELU taking the lead engineering consultant’s role, the urban mega-project aims to create a new ‘civic quarter for all’ and make the area a new centre for Stockholm’s already vibrant street life.



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Mark Dewolf

Mark Dewolf


Chronicling digital’s impact on absolutely everything. More at