Munich's surfers left stunned after famed river wave vanishes | Hacker News Reader

Munich's surfers left stunned after famed river wave vanishes

theguardian.com

146 pointsc42033 comments

I visited Munich back in 2013 and recorded several surfers on the wave [0]. For reference I was standing on the bridge just above the platform in the article's second photo. It was pretty neat, and I'm sad that it might be lost.

[0]: https://www.youtube.com/watch?v=yW4eheoiHY4

I’m sure they will repair it in no time. It’s too much of a tourist attraction to just let it be.

The article mentions they want to bring it back, they just don’t know how they lost it as no structural changes were made.

I think it’s an opportunity to make structural changes and shape that peak like the German Engineers we all know. It will be back better than ever.

It will be fine.

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River engineering: https://en.wikipedia.org/wiki/River_engineering

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The linked Stern article[1] has a before picture showing how the wave used to look.

I'm not that good with hydrodynamics, but since they say nothing structural changed during the cleanup, could it be how quickly they brought the flow back up?

[1]: https://www.stern.de/sport/sportwelt/eisbachwelle--so-funkti...

It could be that, yes.

This is classic turbulent/laminar behaviour, driven by Reynolds number - the volume, the flow rate, the shape of the vessel.

I actually did a hydrodynamics project around this 20 odd years ago as a first year undergrad - one thing I noted was that I had to open valves slowly - any sudden acceleration could dramatically alter the threshold at which one would transition from laminar to turbulent flow, and you could only get back to the laminar regime by entirely stopping the flow, and bringing it back up, slowly.

According to other sources (German: https://muenchen.t-online.de/region/muenchen/id_100983050/mu...) some experienced surfers also say that the water level has been unusually low since the reopening (1.40 m and has since dropped to 1.21 m instead of the usual 1.50 m), which of course influences the flow. So some issue with the weirs regulating the flow is suspected - if it's "only" this, it might be quick to fix...

Watching surfers in the middle of this park was one of my favorite things to do in Munich. What a bummer. I'd be surprised if they had any luck at all restoring it.

The first time I saw them was around Christmastime and I was just stunned by the sight of surfers in the middle of a snow-filled park.

oh darn heading to munich soon...it would've been cool to see

Give it a week and check back, the surfers are a strong community and there is public support for getting the wave back

Why don't you think they'll be able to restore it? Manmade standing waves are common (and the Eisbach was manmade in the first place.)

I know it’s a technicality, but the wave is at the very beginning of the park. Not the middle. I can very much recommend walking at least until the lake, if you happen to be visiting Munich. That would be about 1 third of the park.

For the history nerds. The Eisbach wave was the world's first river wave. And is the fastest still. The second was the one in Montreal, Habitat 67. 1998. Bigger, wider, but a real big river. And also too many people. Third was ours, 1999. Radetzky Graz, Austria. Bigger, higher, but was not running that often. But was officially recognized, and allowed. No police harassment as in Munich. Now destroyed by the local energy company.

We had to repair our wave every few years. Munich does it similarly. Many good waves are now destroyed, because the repair became troublesome. In Munich they already destroyed their 2nd wave, Flosslände, and the third, the best but deadly one directly in the river is forbidden. In Graz we had 5. Montreal also has more. Boisy is good. Swiss and French also have some.

I really hope they get manage to recover it. I grew up surfing in Central Florida and even I knew about it and had seen pictures of it. I finally went there a few years ago and it was a blast to see people surfing it.

Okay, I'll bite. Where do you go surfing in Central Florida?

Not OP, but... Cocoa Beach? Home of Kelly Slater?

I think this was meant in jest, but Florida is not that wide on the peninsula. You can drive from Clearwater to Cocoa Beach (the entire width from west to east) in about 2.5-3 hours. So if you live in the middle like near Orlando or Gainesville, you just...drive an hour to go surfing.

Also Central Florida usually means in the middle North/South, and hence includes the coasts. At least, that’s how I’ve heard it.

I surfed this more than a decade ago. Definitely more of a novelty than anything I'd want to do regularly, but it was fun to try even if the water was freezing.

Just adding that when I rode it, they had slabs of wood under the bridge to manipulate it. Sounds like they may not do that anymore

I guess they could model the river mathematically. I would not be surprised if there are two or more "stable" stream patterns. Perhaps it resets naturally after one year.

Sure they could... the problem is just that apparently no structural changes were made during the cleanup, but the wave was there before they turned the water off and gone after they turned it back on. And they don't have to wait for a year, they can adjust the flow - the wave is situated in a "brook" very near the point where it exits a tunnel through which it flows under much of the city, so it's heavily regulated (see this map for all Munich "brooks" on the West side of the Isar: https://upload.wikimedia.org/wikipedia/commons/f/f3/Karte_M%... - blue are the current ones, dark blue is in tunnel, the purple ones are historical, the Eisbach is #55 in the top right corner).

It wouldn’t be the first time they built a mathematical and physical model of the Isar River in Munich’s inner city, of which the Eisbach is a part.

https://iprpraha.cz/uploads/assets/dokumenty/sharing_experie...

Have they tried turning it off and back on again?

That’s what they did and that broke the wave.

Sediment perhaps?

As you read in the article, yes, they did, and that's what caused the problem.

Well maybe they just need to jiggle the handle.

The forced update bricked the wave :(

Yes. Techniker ist informiert.

> Have they tried turning it off and back on again?

Yes, but the bloody thing updated itself between reboots. But, don't worry, Microsoft will release a fix in a couple of years.

Hope they can bring the wave back soon, it’s such a special part of Munich’s spirit and surfing history.

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