Passenger Trains > Paper asks: On BART, noise annoys, but can it be harmfu

BART press release, of sorts: http://feedproxy.google.com/~r/BARTNews/~3/Tz4mLzJH0LE/news20100907.aspx

I suppose that's a reaction to the front-page article in today's SF Chronicle, titled "On BART, noise annoys, but can it be harmful?" which will be available on-line starting Thursday at http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2010/09/07/MN1N1F8CCH.DTL


In the press release is this tidbit:

BART Chief Communications Officer Linton Johnson said that according to the report, "You’d be hard pressed to find a quieter system" anywhere in America.


Really now? I'd invite our Trainorders community to chime-in on that assertion! I think BART is INSANELY LOUD.

What do you think?

Highspeed Wrote:
-------------------------------------------------------
> BART press release, of sorts:
> http://feedproxy.google.com/~r/BARTNews/~3/Tz4mLzJ
> H0LE/news20100907.aspx
>
> I suppose that's a reaction to the front-page
> article in today's SF Chronicle, titled "On BART,
> noise annoys, but can it be harmful?" which will
> be available on-line starting Thursday at
> http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2
> 010/09/07/MN1N1F8CCH.DTL
>
>
> In the press release is this tidbit:
>
> BART Chief Communications Officer Linton Johnson
> said that according to the report, "You’d be
> hard pressed to find a quieter system" anywhere in
> America.
>
>
> Really now? I'd invite our Trainorders community
> to chime-in on that assertion! I think BART is
> INSANELY LOUD.
>
> What do you think?

High,

Compared to many systems BART is relatively quiet. What you get however are sounds that other systems until the last 10 or 15 years did not. The sound of the electronics for the traction drives are much higher pitched, and tend to last longer. BART also, because it is really a high speed interurban railway, you have much different track noise. BART is almost all welded rail which "sings" as the cars pass. Older systems in which stations are closer together and have much more point work (turnouts and crossings) which generate more pounding noise. One thing that BART did discover, was that "sound walls" don't negate sound as much as change it and move it. For instance, before the sound walls were build coming out of the Berkeley subway towards El Cerrito. The noise was pretty loud right by the tracks. After the sound walls were built. The sounds was different, not so much muffled as softer. It also moved from right near the tracks to about 3 or 4 blocks away. So the next time you travel, go to Chicago to the EL, or to the Boston T system and let us know what you think.

J.

I think that reports done back in 1997 (13 years ago) have very little information to help us understand the noise levels currently experienced on the BART system. Rail/Wheel maintenance programs currently in place are a better indicator. I'm glad that reported rode all those miles and did a current measurement.

However, based on my personal experience from 10 years ago, I think the Washington DC Metro is less noisy.

When I ride BART hearing protection is mandatory.

Between their rail grinding and wheel turning they have hit just the right harmonic to create a nasty loud squeal.

Been on Boston and DC Metro and never thought I needed to wear hearing protection as I do on BART.

Daylight

I have ridden the Chicago EL, D.C. Metro, New York Subways and Denver (DIA) Airport's subway just to name a few.

Being a Locomotive Engineer I feel that I am well qualified to comment when it comes to train noise; be it inside the cab, train, etc.

For me hearing protection is MANDATORY when riding on Bart. Of all the trains/subways I have ridden and operated, BART, by all means takes the taco when it comes to noise. Infact that has ALWAYS been my only complaint when riding BART.

Another poster mentioned traction motor noise as being the culprit. I highly disagree. I know exactly what traction motor noise sounds like. Like all other railroad "sounds" my ears (and all railroaders)are "tuned into them". Yes, there is SOME traction motor noise on BART. But, it is the noise created by the wheel and rail that is unbearable for me.

Say what you may about BART. EVERYONE is entitled to an opinion!

I was very surprised at how much quieter both the U-Bahn (subway) and S-Bahn (surface or elevated) transit lines in Berlin were than, say, the Chicago CTA trains. Anyone know what they do differently?

Anybody have sound level measurements to go along with this discussion?

Ray

My impression always has been that BART rail-wheel interface is surprisingly noisy when compared to even such ancient systems as New York. I have never quite figured out how they manage to produce as much noise as they do. Sounds to me like they suffer from chronic "Roaring Rail Syndrome" which can easily be fixed by a somewhat regular grinding of rails to get those imperfections that pile upon the rail surface, and also incidentally increase the longevity of the rails.

Jishnu.

It's about time somebody in the media mentioned the excess BART noise! I've been riding BART from the beginning and the noise level has definitely gotten MUCH worse as the rails and equipment aged. I live about a mile from the tracks (near Bayfair station) and in the beginning I could barely hear the trains from my place. Even though some recent rail grinding has somewhat helped (for now anyway!) the trains sound like they now are MUCH closer. I pity the people who live trackside! As far as the noise in the Transbay tube, it's absolutely horrible! You can't even have a conversation while under the Bay. When I forget to bring my old railroad earplugs with me I really suffer. I almost wish I was back running one of those howling F40's on Caltrain, even if those noisy rattle traps destroyed part of my high frequency hearing in the days that SP not only didn't provide us ear protection but frowned on it's use! By the way I'm not generally a BART basher. Aside from the noise I love the system and use it regularly!

Bartd's noise problem is caused by using resilient wheels on the rigidly supported track. The wheels are aluminum centers with steel tires mounted with a thin elastomer "film" between it and the aluminum center. The rigid track is on the elevateds, the transbay tube, and all the subways.

What happens is on these sections of rigid track is that the tires set up harmonic vibrations in the rails which leave corrugations in the surface of the rail head. In the 1950s-1980s, the SF Muni had the same problems with the PCCs and the super resilient wheels. They made virtually the same noise going up and down Market Street.

On open track with ties, like the line to Concord and in the vicinity of the McArthur station, the track structure is able to absorb the harmonics, so the corrugations don't form, so these sections of track are quiet. It was the same on the Muni, the open track on 19th Ave and in Twin Peaks and Sunset tunnels didn't have the problem.

For a while the Muni ground the rail head to get rid of the corrugations, but stopped by doing this around 1970. Bart may claim to have rail grinders, but I've never seen them in use. My house is about 4 miles away from a Bart elevated, and I can hear a train go by with my windows closed. Bart needs to get of it's dead a** and grind the railhead on a regular basis.

Unfortunately, every time the rail grinder goes out to work, the area residents complain about the noise. Work like that is done overnight while the system is shut down. BART has to go to great lengths to notify area residents in advance, although I am not sure what provisions they make for them.

As for the Trans-Bay Tube, it is unfortunately almost all one long curve, up and down, which can't make the situation any better.

Gary

You think it's bad in the transbay tube? On the new segment between Colma and SFO it is HORRIBLE -- louder than a rock concert, and that segment was just built!

Wheel and rail noise for sure: and I likewise ride systems all over US and Europe: BART is dangerously noisy, much more so than any other rail system I have been on. And not just in the tunnel: I have ridden all of the system often, and the terrible high-pitched squeal is everywhere: maybe worst Oakland to Concord.

My idea was that a rail lubricant salesman should call on BART.

David

I remember that there was quite a bit of noise but I expected it, especially while the thing was in a tube. I've been on the New York systems, Boston, DC Metro and they had a similar noise levels. I do remember riding the Blue Metro line in LA and above ground it was noisy.

John

Please let me second the motion regarding the noise from SFO. From the airport to Colma and up to Daly City it is just awful!

John Gezelius
Tustin, CA

Yes, oh yes, Highspeed... Bart is one of the LOUDEST transit systems, indeed. I did a comparison to Chicago's 'L' when I was last back there (in August) and it's not annoying at all compared to that ultra-sonic BART noise--it's off the charts (Yes, I wear earplugs as well!).

After spending years on F-40's with earplugs firmly in place, I can do without the rock concert effect on BART as well; however, I remember hearing it from a distance in W.C. and Pleasant Hill, and it wasn't at all unpleasant.

You would like the Montréal Métro. We rode it to the 1967 worlds fair. That was the first year of operation.
Rubber tires in a subway environment. And unique brakes, advanced for that era.


"Design: Rubber tires make the Montreal Metro exceptionally quiet, transmit minimal vibration, and help the cars climb uphill more easily and negotiate turns at high speeds. However, the advantages of rubber tires are offset by noise levels generated by traction motors, which are noisier than the typical North American subway car.
Montreal's metro trains use electromagnetic brakes, which create retarding forces against the side rails of the track. The electromagnetic brakes are generated by the train's kinetic energy until it has slowed down to about 10 km/h (6.2 mph). The train then uses composite brake blocks made of yellow birch injected with peanut oil to bring it to a complete stop."

http://en.wikipedia.org/wiki/Montreal_Metro#Design_2

Cal-P

I thought it was me. I live in a relatively quiet country town and found BART uncomfortably loud, and much worse than I remembered it right after it opened. BART trains have awakened me from a half mile away at two locations [I was glad they don't have night owl service], and I will bring ear protection on my next trip to the City. Rich Hall, Fall River Mills,Ca.
P.S. Would voters have approved the bonds if they'd heard a recording of what "quiet" meant to BARTD executives/directors? You can bet none of THEM live within a mile of the tracks.

Ray_Murphy Wrote:
-------------------------------------------------------
> Anybody have sound level measurements to go along
> with this discussion?
>
> Ray

One of the TV station reports said they recorded 100 db under the Bay and compared it to the sound of a jackhammer! Linton Johnson the media spokesman for BART, attempting as usual to put a good spin on BART's shortcomings, said something like "Well yeah...but it's not continuous like a jackhammer! It only goes on for 30 seconds or so at a time!". Say what? I think it's about 4 minutes going through the tube under the Bay...and then there is that underground section through Berkeley which also seems to be getting worse...and that SFO-Colma section which I haven't had the displeasure of riding on lately. Probably several other spots too! Nope BART has a definite and increasingly worsening noise problem and it's about time people started recognizing it and complaining!

johnw Wrote:
-------------------------------------------------------
> Ray_Murphy Wrote:
> --------------------------------------------------
> -----
> > Anybody have sound level measurements to go
> along
> > with this discussion?
> >
> > Ray
>
> One of the TV station reports said they recorded
> 100 db under the Bay and compared it to the sound
> of a jackhammer!

If it's greater than 100 dBA even for relatively short periods, they are probably violating OHSA exposure limits for employees.

Ray