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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

#231

Post by layoutIfNeeded »

robbrown451 wrote: post #229
dessant wrote: post #14

I'm just glad they identified the source of the hum, many people are impacted for years by unexplainable sounds, and it is maddening. It took me and my neighbours a month to find the source of a hum that was resonating with our windows. It was torture, with midnight walks and lurking around potential sources, mapping nearby industrial sites, and questioning our sanity, while our windows were vibrating without a stop.…

Had that where I live, for the first year. San Francisco as well (it's windy here!) Finally after about a year of it, figured out it was the turbine ventilator on my next door neighbor's roof. She was a bit elderly and didn't seem to want to do anything. Luckily I realized I could reach it from my own roof. So I jammed a stick in it and it never spun again. Problem solved!

You realize that those ventilators need to spin in order to function, right? Now her apartment won’t be ventilated properly.

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

#233

Post by personlurking »

dessant wrote: post #14

I'm just glad they identified the source of the hum, many people are impacted for years by unexplainable sounds, and it is maddening. It took me and my neighbours a month to find the source of a hum that was resonating with our windows. It was torture, with midnight walks and lurking around potential sources, mapping nearby industrial sites, and questioning our sanity, while our windows were vibrating without a stop.…

In my last apt, once in a while I'd start hearing a far-off hum, and it would always make my wifi go out. I eventually tracked it down to a huge backup generator for a commercial plaza a few blocks away, but telling my ISP that a distant hum cuts out the internet every once in a while wasn't going to get me anywhere.

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

#234

Post by robbrown451 »

layoutIfNeeded wrote: post #231
robbrown451 wrote: post #229

Earlier quoted context omitted.

Had that where I live, for the first year. San Francisco as well (it's windy here!) Finally after about a year of it, figured out it was the turbine ventilator on my next door neighbor's roof. She was a bit elderly and didn't seem to want to do anything. Luckily I realized I could reach it from my own roof. So I jammed a stick in it and it never spun again. Problem solved!

You realize that those ventilators need to spin in order to function, right? Now her apartment won’t be ventilated properly.

It's just an attic ventilator. And yes I know. My sanity outweighs the air quality of her attic. And I told her first.

(FWIW she's a very nice lady and has long since sold the house and moved away. I told her I had done that at one point and she just chuckled and didn't care)

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

#235

Post by frosted-flakes »

Nitramp wrote: post #170
sevencolors wrote: post #26

Earlier quoted context omitted.

I imagine it’s just going to be ignored. Like the bart “screeching” they never fixed.

That's amazing. According to this article, bart is now moving to tapered wheels instead of plain cylindrical: https://sf.curbed.com/2018/6/11/17449460/bart-screen-convers... My understanding was that all rail systems since roughly forever use tapered wheels. Primarily to reduce wear, by having the tapered wheels self center instead of grinding against the track. It's really odd that they seem to just roll that out in…

> unlike the cylindrical profile which again just steers with the flange basically rubbing against the edge of the railhead.

That's crazy. That means that the wheels are actually slipping when going around a corner, because the wheels are all the same diameter. Unlike conical wheels, which are essentially self-steering.

Here's a great explanation by Richard Feynman: https://youtu.be/WAwDvbIfkos

How could the BART trains possibly have cylindrical wheels? Conical wheels have been used on trains for ages, so that's seems weird. But doing some research, it seems that, yes, they were cylindrical:

> Queensland Railways, for its first hundred years, used cylindrical wheels and vertical rails. With non-inclined rails and cylindrical wheels, the wheel squeal from trains taking curves on that railway was slight. After adopting coned wheels and inclined rails from the mid 1980s, the wheel squeal from trains curving at the same location and at the same speed decreased immensely. Some modern systems, such as Bay Area Rapid Transit (BART) in San Francisco, use cylindrical wheels and flat-topped rails; BART is now switching to conical tread to reduce the noise caused by flange/rail contact and loss of adhesion of one of the wheels on curves.

-- https://en.wikipedia.org/wiki/Wheelset_(rail_transport)#Semi...

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

#236

Post by dustym »

joebergeron wrote: post #183
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. Very funny to be reading this. I grew up in Falmouth, and lived there until 2014 when I graduated highschool. I obviously wasn't incredibly attuned to this issue, but as I recall, the only people opposed to the installation of the turbines were a very small, very vocal, and very, very, wealthy minority of people who owned mind-bogglingly expensive beach houses and lived there two months out of the year. I'm fairly…

I have no opinion on anything, FWIW because I actually spent most of my time in Woods Hole. My recollection of all this is from the local paper.

EDIT:

Cliche as it as, the fish bites at Landfall are pretty good! And it was always fun to swing by the aquarium after hours and listen to the seals bumping around in their pool. It's a beautiful place to visit if you ever get a chance.

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

#237

Post by hedora »

sevencolors wrote: post #26
bitcharmer wrote: post #13

Earlier quoted context omitted.

I don't think SF residents are as thrilled. It's overwhelmingly loud.

I imagine it’s just going to be ignored. Like the bart “screeching” they never fixed.

The bart didn’t do that when it was new. Apparently, standard railway maintenance involves grinding busy tracks down on a regular basis (so the track has a round crown on top instead of being flat).

Of course, the BART system simply fails to do the maintenance. I used to commute through the transbay tube and would happily join a class action suit over the hearing loss.

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

#238

Post by 1propionyl »

TigeriusKirk wrote: post #189
Balgair wrote: post #71

Earlier quoted context omitted.

Ok, I'm on board here. This is really cool. Yes, it cannot be a 24/7 thing, the harp/bridge is too loud. Also, putting resonances into a suspension bridge is likely to be unsafe. That said, like the chiming of church bells in a village, it may be used selectively. I can imagine some Burners quickly putting up an adjustable mechanism to have the bridge sing/chime. Something that can point into the wind correctly (to s…

I joked with a friend today that with San Francisco being San Francisco, someone will have a system for making it play Carol Of The Bells by next week.

Rigging something so that it plays Blowing in the Wind would be much more fitting.

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

#239

Post by Bud »

pmiller2 wrote: post #190
peterkos wrote: post #172

Earlier quoted context omitted.

every musician ever: A440 PROVEN BY THE BRIDGE

A440 is not as universal as you’d think. Tunings as low as A435 and as high as A466 are in use even today. See https://en.wikipedia.org/wiki/A440_(pitch_standard)

"As low as A=435"? The reality is much stranger! Baroque groups such as Philharmonia Baroque Orchestra, and American Bach Soloists, and many others, routinely perform at A=415, which is the standard accepted "Baroque" pitch these days.

Earlier music is sometimes performed down around A=390.

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

#240

Post by hedora »

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.

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