The bLINK artwork is built to withstand vibrations and harsh weather for decades
When it comes to public infrastructure, we tend to think of what facilitates our everyday lives in the direct sense. Bridges, railways, roads, they’re all there to streamline how we get from point A to B, while also keeping us safe. But by turning to more artistic expressions, public spaces can also be set up to speak to our inner lives. And that’s critical – if we are to thrive and feel good in our shared, outdoor human-made environments, in which we spend a significant amount of our time in, we cannot neglect dimensions of what it conveys with its presence.
In Gothenburg, Sweden, more precisely the traffic junction Olskroken, there’s one example of such a recent public infrastructure project, designed and built with the explicit purpose of enriching our lives with its contemplative expression. Set on a railway bridge that spans over the heavily trafficked E6 highway beneath, the artwork bLINK, created by the Swedish artist Katharina Grosse, instills a splash of pink and intricate pattern of steel in the middle of the otherwise grey traffic junction.
© Katharina Grosse
With its imposing size, reaching the heights of a three-story building and weighing over 35 tons, constructing and lifting the artwork in place presented its fair share of challenges. Tasked with turning Katharina Grosse’s creation into reality was HAHNER® Technik GmbH & Co. KG.
So, what construction challenges did HAHNER encounter while assembling bLINK, and how did Nord-Lock washers help in overcoming them?
THE IDEAL CHOICE IN MANY WAYS
Naturally, an artwork situated in the middle of a traffic junction, and on top of a bridge, will face constant vibrations and dynamic loads from the steady flow of cars and trains. Therefore, the engineering team at HAHNER had to find a fastening solution that would manage to keep the bLINK construction, and the ones passing through, safe, no matter the extremity of the vibrations.
“With this construction, we definitely had what you can call a “vibration problem” says Bernhard Hahner, Managing director at HAHNER.
After having considered several solutions, Hahner ultimately decided to go with Nord-Lock, and specifically stainless-steel washers NLss-254 in sizes M6, M8, and M10. The decision was based on Nord-Lock’s documented, unparalleled performance in securing bolted connections in demanding industries. But that was not the only reason. Bernhard Hahner explains.
“Nord-Lock also turned out to be the easiest, most time-efficient solution for assembly. We didn’t have to redesign or rethink any parts of the original design. So, it was really a plug-and-play situation, which fortunately did not make an already complex construction even more so”
Another critical upside with the NLss-254 washer is that it is the only securing washer made of stainless-steel washer that carries the CE-marking. Therefore, Hahner and other constructors can rest assured they are using components that comply with strict quality standards.
A CLIMATE MAKING ITSELF KNOWN
Another challenge HAHNER had to take into account was the impact that Gothenburg’s diverse, quickly changing weather would have on bLINK. HAHNER was aware of the significant, sudden changes in temperature of the region, which would cause the relatively thin aluminum plates on bLINK to expand more than the steel structure. Therefore, between the plates and the structure, the bearings would have to allow for some degree of sliding.
“The team at Nord-Lock were able to fix the bearings of bLINK’s bolted connections, which allowed for the small sliding that the construction needed” says Bernhard Hahner.
Moreover, Hahner knew that they had to consider the effect of thermal expansion in the construction’s material. Just as with vibrations and dynamic loads, thermal expansion causes movement, which could result in unintentional self-loosening of the bolted connections. However, the wedge-locking technology of the NLss-254 washer was what proved to be the best solution in light of such challenges.
THE ISSUE OF CORROSION
Besides the issue of potential loosening of bolts, a humid climate, with occasional harsh, salty winds presented another problem while assembling and erecting bLINK – corrosion. As an artist, Katharina Grosse has naturally had a clear vision of aesthetics. So, for bLINK to retain its distinctive, all-encompassing, radiant pink color for years to come, it was crucial that the components used to assemble bLINK would not rust and, as such, change color. Fortunately, the issue of corrosion—and the potential discoloration it could cause—was something the NLss-254 could handle.
“The stainless stee SMO uses the steel material 1.4547, which is a special, high-corrosion-resistance material” says Frank Götz, Business Development Manager Construction at Nord-Lock Group. “The wedge-locking washer used by Hahner for the bLINK project is one of the best alternatives to date for ensuring that the bolted connections do not stand out negatively due to rust buildup.”
A MONUMENT THAT WILL LAST FOR DECADES
bLINK might be an artwork, but it is designed to match the lifetime of a proper building, meaning that it should remain a part of Olskroken for decades to come. Just as with any other construction, the bolted connections play several key roles for it.
From dynamic loads to thermal expansions and corrosion, the external threats to the safety and structural integrity of bLINK turned out to be quite a few. But with Nord-Lock washers, HAHNER, along with everyone fortunate to pass bLINK occasionally or daily, will be able to enjoy the stunning presence of Katharina Grosse’s creation for the unforeseeable future.