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New slats make the Golden Gate Bridge sound like a David Lynch movie

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Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#301

Post by heavenlyblue »

jml7c5 wrote: post #225
harikb wrote: post #196

Earlier quoted context omitted.

My backyard backs in to a strip mall with an auto mechanic shop. We hear a high pitch sound some times of the day and when we step outside to inspect, we only hear a different sound from the shop behind - a typical machine running, but not necessarily unpleasant. Turns out the walls are able to mask the lower pitch sound somehow and let in only the unpleasant higher pitch sound to the inside of the house. I am not su…

Have you checked for windows resonating? It would be surprising if walls were acting as a high-pass filter. Could also be electronic noise. I wonder what the machine is.

Do you think the high-pitch sound reflects from the house opposite to the windows?

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#302

Post by bpicolo »

mmanfrin wrote: post #153
pronoiac wrote: post #34

Earlier quoted context omitted.

It's gotten quieter since 2017 - https://www.sfgate.com/bayarea/article/BART-noise-levels-dec...

"BART says", but as of 6 months ago I was compelled to buy ear plugs for my commute. There's a stretch just before West Oakland (Westbound) that I'm near certain has given me ear damage.

I haven't lived in the Bay for a few years but this brings me flashbacks to that part of my commute.

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#303

Post by petee »

enchiridion wrote: post #259
konschubert wrote: post #177

Earlier quoted context omitted.

Well, I guess the goal may have been to let the wind pass through.

I think this fence was explicitly designed to block wind.

The article says it was to reduce wind resistance. In a separate video, the manufacturer states this was needed to offset for the new suicide net

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#304

Post by rini17 »

zamadatix wrote: post #268
pengaru wrote: post #180

Maybe they should find a way to generate electricity from the bridge, it sees plenty of wind practically every single day for the same reason the SF bay is great for sailing. https://patents.google.com/patent/US9444372B2/en https://en.wikipedia.org/wiki/Vortex_Bladeless

The slats were added to reduce wind resistance. Generating power from wind would greatly increase wind resistance.

It depends. Doubt that would affect wind resistance if the shape stays the same, only the vibrations would be partially dampened by added piezoelectric generators. Draining some mechanical energy by turning it into heat+electricity might even improve the mechanical properties.

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#305

Post by ilaksh »

zamadatix wrote: post #268
pengaru wrote: post #180

Maybe they should find a way to generate electricity from the bridge, it sees plenty of wind practically every single day for the same reason the SF bay is great for sailing. https://patents.google.com/patent/US9444372B2/en https://en.wikipedia.org/wiki/Vortex_Bladeless

The slats were added to reduce wind resistance. Generating power from wind would greatly increase wind resistance.

If instead of the slats they installed thousands of tiny vertical axis wind turbines, perhaps much of the energy would be used to turn them rather than vibrate the air. I guess it might also make a noise, but maybe quieter or less grating.

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#306

Post by metalliqaz »

rasz wrote: post #70
dustym wrote: post #24

Earlier quoted context omitted.

Two unrelated anecdotes: 1. A few years ago I spent some time in Falmouth, MA and there was an ongoing battle over newly installed wind turbines. The humming sound was getting to people, including to the point where they were getting headaches. Some people heard it and others didn't. The locals were going to war with the initiative. This article reminded me of that and I checked in on the ordeal. Looks like they shut…

1 Modern CFD techniques enable almost silent blades. If a $10 computer fan can have special dimples/channels why cant wind turbines https://www.quietpc.com/nf-a12x25-5v https://cougargaming.com/us/products/cooling/cfd_red_led_fan... https://aerocool.io/us/product/silent-master-blue-20cm/

Fans are not turbines. You understand that, right?

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#307

Post by ilaksh »

I wonder if they will now need to install thousands of rubber vibration dampeners wedged between the slats.. like large versions of tennis racket string dampeners.. if that is possible to do without catching too much of the wind trying to pass through. Maybe only on every other slat, or every three slats, could reduce the noise at least somewhat.

So then someone would need to custom manufacturer all of those pieces of rubber and then they would all need to be jammed in there. But then the weather would probably degrade then over time.

I just wonder how many millions are going to be spent on mitigating this.

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#308

Post by tripzilch »

marton78 wrote: post #299
PascLeRasc wrote: post #75

Earlier quoted context omitted.

Berlin has some absolutely beautiful church bells. The overtones and reverb from all the walls are so chilling, it makes you feel like you're inside the bells or something. I recorded one of them: https://sndup.net/2h7t/St+Joseph+Kirche.m4a

Guy from Berlin here. Isn't this how church bells are supposed to sound? Do they sound different in other places?

They sound like that in the Netherlands too.

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#309

Post by JoeAltmaier »

nullc wrote: post #276
JoeAltmaier wrote: post #213

We just live with a very loud sound at our house. Run water for any reason. When you stop, some 0-15 seconds later an enormous sound reverberates thru the house. Plumber says its 'water pipes growing or shrinking, rubbing against the straps'. But it goes on for 10-30 seconds. No water pipe in the world moves that long/that much?

If its water hammer (as it sounds like it is)-- it can fatigue joints and valves and cause leaks over time. Water hammer can be fixed by putting hammer arresters at the right locations.

But - every tap in the house causes it! And the toilets. And the shower. And the outside hydrant. Where would we put such a thing?

Re: New slats make the Golden Gate Bridge sound like a David Lynch movie

#310

Post by JoeAltmaier »

hedora wrote: post #240
JoeAltmaier wrote: post #213

We just live with a very loud sound at our house. Run water for any reason. When you stop, some 0-15 seconds later an enormous sound reverberates thru the house. Plumber says its 'water pipes growing or shrinking, rubbing against the straps'. But it goes on for 10-30 seconds. No water pipe in the world moves that long/that much?

Definitely water hammer. Find a different plumber. Be sure to review the first one on yelp after the second confirms.

Online I see that described as a 'hammering sound'. Not our problem. We have an extended thrumming that lasts for many seconds. And it can be delayed from the event by seconds. Is that definitely the same thing?
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