Troubled Bridges Over Danish Waters

Sometime this summer, Copenhagen should open an impressive new bridge that will help reshape the layout of the city’s center. The Inderhavnsbroen (“Inner Harbor Bridge”) will cross Copenhagen’s harbor, connecting the 17th-century waterfront at Nyhavn with the rapidly transforming islands that make up the core of the city’s former port. While the bridge won’t span a vast space, it will make a big difference, cutting out a detour that makes the islands slow to reach, considering how close they are to the city’s heart.

Designed to open and close to allow ships through what is still a shipping channel, the bridge also has a typically Danish quirk: it’s only for cyclists and pedestrians. As over 50 percent of all central Copenhagen journeys now take place by bike, this needn’t be any bar to its popularity. Indeed, by making the other side of the harbor more easily accessible by bike than car, it might even contribute to a further modal shift. This all sounds great, but there’s currently a slight problem with the bridge. It won’t close.

At least, not properly. Despite an ingenious design, generous funding, and a high profile-location in the city’s heart, the Inner Harbor Bridge has met setback after setback over its seven-year genesis. Construction officially ended last summer, but it’s been blocked off ever since, as if to goad passersby still obliged to take the long way around.

The problem stems from the bridge’s central section. Designed in a slight S-shape, the bridge consists of two fixed spans that both contain a retractable arm. These arms can extend to form an unbroken span or retract back inside the fixed spans to create a navigable gap. To form a full span, the arms need to meet in the middle, earning the design the nickname the “Kissing Bridge.” When perfectly aligned, they automatically latch together when protruding tongue-like bolts enter complementary holes in the other span. These bolts aren’t perfectly aligned, though—they’re off by six to eight centimeters, which is enough to prevent them locking correctly.

Close-up of the bridge revealing the retractable sections inside the fixed spans. (Kyle Copas/Flickr)

The city is saying the misalignment is not a design flaw. They’re actually blaming the weather. According to the Copenhagen Municipality construction adviser Erik Sørensen, a combination of cold days, bright sunshine, and chilly seawater has created conditions the designers hadn’t entirely predicted. He told a trade publication:

“When the sun begins to shine, the retracting arms’ surface is much warmer than their bottom, as is also the case with the curving bridge. This is actually taken into account with the design, but if the heating is uneven, there comes an unexpected twist that means the bridge cannot close.”

The problem can probably be resolved with several tweaks. Possible solutions include making the tongue bolts more pointed for easier insertion, widening the collars around the corresponding sprockets, and fitting these sprockets with some mechanism to guide the bolts in.

But while this sounds simple enough, it’s only the latest of a string of faults that has made the bridge project into an ongoing headache. Originally slated to open in 2013, the bridge has been delayed by a contractor’s bankruptcy and by wrangles with steel producers. It was then held up further when a fault was discovered with the wire system used to move the opening spans. “Bridge Delayed” has become such a frequent local headline that it can be hard to guess exactly which of the many delays the accompanying article refers to.

Meanwhile, across town in the city’s South Harbor, there’s another bridge project with the opposite problem. This time, it may never open at all—not due to design flaws, but to funding problems. Thanks to a lack of cash, the  unnamed new bridge, which was initially proposed as a moveable link, may now be just a regular bridge with a fixed span.

To understand why this matters, you need to look at what’s been going on in Copenhagen’s South Harbor, a construction hotspot that’s recently seen some of the city’s most frenetic development. Located a mile or so south along the same sound as the Inner Harbor, this area of the city is steadily losing its character as an ex-industrial backwater. Much new housing has been built here, not just on the existing quayside, but on a string of small artificial islands that jut out into the harbor’s waters. These islands are pretty well designed, but have stirred up some debate—they are built in public waters, but their housing is not necessarily affordable. While any extra accommodation in Copenhagen is arguably welcome, this still leaves the city open to accusations of giving away public goods for private profit.

A view across Copenhagen’s South Harbor. (Stig Nygaard/Flickr)

The planned bridge, over the Frederiksholmsløbet canal, is intended to allow swifter access to these islands. Indeed, the islands themselves may have had planning permission granted a little more easily because the city was promised a movable bridge, meaning that the area’s canals would still remain open to watercraft.

Now that the islands have been constructed, it turns out that the municipality and the landowners only have 77 million Danish Kroner ($11.6 million) left in the pot to build a bridge, which would provide a faster route to the new islands beyond. These funds would be enough for a fixed link, but not enough to construct a bridge that actually opens. Unless the project finds some extra funding store, the movable link plan will have to be scrapped.

This matters. If the still quiet South Harbor is ever going to become a lively, thriving part of the city, it will need its waterways to be open to use, not least by people who bought housing there imagining they’d have easy access to pleasure craft. What’s more, the city granted public water space for the islands because it believed more housing was in everyone’s interest—but also because it expected that the canals along the quayside would remain as a public amenity. The adapted bridge plan suggests this may not still be the case. With the city planning yet more artificial islands jutting out into publicly owned waters in the future, this seems like a setback to a plan that hoped to combine private housing growth with public leisure opportunities.

So are these two problematic projects a sign that Copenhagen’s famously good urban planning has gone awry? Not necessarily. During the period in which the city has been embroiled with the Inner Harbor Bridge, it has also produced other world-leading projects that show it to be very much on course. These include the elevated Cycle Snake bikeway along the waterfront and the eye-catching Circle Bridge, located just a few hundred yards away from where the Inner Harbor Bridge remains blocked off. These are still projects that many cities could only dream of raising the funds and political will to emulate. Copenhagen hasn’t lost its infrastructural edge. For outsiders who idolize the Danish capital as an ideal urban template, however, this tale of two bridges should provide some qualifying context. Copenhagen isn’t necessarily less vulnerable to design or funding screw-ups than anywhere else.