The ironic part is "The bridge replaced a steel truss bridge built in 1895 at the same location". Engineers in 1895 knew how to use steel trusses and built a bridge that lasted 100+ years, and in 2012 they decided to use glued wooden beams and it fell apart in 10 years.
Well perhaps Plan Arkitekter and Norconsult can take a trip to the archives and see what the engineers in 1895 knew before building any more structures.
It's a little too strong of a claim. Plenty of poorly designed steel bridges from the 19th century have collapsed as well, despite the superior material.
That's true. But I only meant that particular bridge, which did last for 100+ years. So, when the architects and the engineers go to the archives to relearn a few things, they can focus on the ones which haven't collapsed.
The old one wasn’t wide while the new one had two lanes and a normal sized sidewalk.
Rivers produce lots of moisture.
Corrosion weakens the steel. It's literally the metal flaking away.
All steel corrodes. Even stainless.
Once corrosion sets in and the outside of the metal starts to pit, the corrosion speeds up drastically. (The old area vs volume thing, same thing that makes lump coal difficult to ignite while aerosolized coal dust is practically an explosive).
Here's a modern US bridge - all steel - that collapsed in Pittsburgh two years ago. In some areas over 80% of the original steel thinkness was gone after 49 years.
As always, lack of maintenance and poor design choices (use of corten steel) are the culprit.
"There are more than 617,000 bridges across the United States. Currently, 42% of all bridges are at least 50 years old, and 46,154, or 7.5% of the nation’s bridges, are considered structurally deficient, meaning they are in “poor” condition. Unfortunately, 178 million trips are taken across these structurally deficient bridges every day. In recent years, though, as the average age of America’s bridges increases to 44 years, the number of structurally deficient bridges has continued to decline; however, the rate of improvements has slowed. A recent estimate for the nation’s backlog of bridge repair needs is $125 billion. We need to increase spending on bridge rehabilitation from $14.4 billion annually to $22.7 billion annually, or by 58%, if we are to improve the condition. At the current rate of investment, it will take until 2071 to make all of the repairs that are currently necessary, and the additional deterioration over the next 50 years will become overwhelming."
ETA: Also, the ones that have survived aren't road bridges. They're either railway bridges (and thus were built strong in the first place) or have been relegated to historic preservation/pedestrian use only. Modern cars and (especially commercial) trucks are far heavier than early vehicles. A road bridge built in the 1850s was only designed to carry foot traffic and horsedrawn vehicles.
The purpose of the hull is to protect the paint.
The purpose of the reactor is to drive the paint around.
The purpose of the SUBSAFE program is to ensure the paint comes to the surface and will not be lost.
The purpose of the cathodic protection system is to back up the paint.
The purpose of the weapons is to defend the paint.
The purpose of the Special Hull Treatment is to protect the paint.
The purpose of the Vertical Launch System is to destroy those who would do the paint harm.
This page details the other continuous maintenance going-on. [1]https://www.goldengate.org/bridge/bridge-maintenance/
Now that effectively might mean then combing over the bridge end-to-end and painting as needed so what I said might be a distinction without a difference.
This is basic materials engineering.
So again, do you know this specific bridge was replaced for this specific reason, or are you just making stuff up? Because bumping in on a specific question with a generic answer without any knowledge if that applies to this specific case is making stuff up.
The hostile tone is because you're talking complete nonsense with great arrogance.
Sure, novel things should be tried, but in a conservative manner. Overdesign first, then optimize iteratively. Because failure costs lives.
Bridges on the whole are pretty clearly better built and safer today then they were 130 years ago. I don't think there's any significant argument to the contrary. There are outliers in both directions, obviously. The old one at this site looks like it was pretty great. The new one sucked. That doesn't say much about why that was true, just that it was.
For sure, we can each talk about different things. I can talk about ironic things and you can talk about statistics, and we can still be friends!
> That doesn't say much about why that was true, just that it was.
Well, why do you think it sucked?
And why not? In this particular case, the statistics did not justify the expectation that this bridge would be at least as robust as the one it replaced.
There's a general point to be made about engineering progress, but here we have a case which bucks the trend. Speaking in generalities when the topic is a specific incident is a way of missing the point.
I guess that’s what they’re going for when they say aesthetics had too much of a focus?
I don't see how that follows? Lots of steel bridges have failed over the past 130 years. The overwhelming majority of new-built bridges or any material don't fail.
People really, really want this to be about "aesthetics" because it confirms their priors about being smarter than the rest of the world or whatever. I'm just saying that's 100% bunk and that there's zero evidence for that hypothesis.
Architecture has had a "strong focus on aesthetics" since the very first stones were piled up to make a temple. Let's not get ahead of ourselves here.
Disagree. In late 19th century steel girder bridges were well understood and many of them survive to this day.
They were usually replaced due to changed demands (wider roads, heavier loads), not because of failure.
Or is your claim a mere circular argument, since we can deduce that a steel bridge was poorly designed if it has since collapsed?
This fad has now passed and there have been several news stories about what a bad idea it was. I guess they were trying to get back to using more natural materials.
It sounds like they didn't do it right, though.
https://www.di.se/hallbart-naringsliv/trahustrenden-nar-nya-...
https://www.tmf.se/bransch-naringspolitik/branschutveckling/...
The trend goes back to 2014 even, so it wouldn't surprise me if this wooden bridge built in 2012 was part of that whole wave.
Well, was.
Sarcasm aside, I see more beauty in doing something well than whatever this was. Are they hiring art students to build bridges now?