Train noise in subway

I haven't been on subway systems outside the US for a very long time now, but what I remember of them--Paris, London, Prague, Budapest--is the platforms seemed much quieter than in NYC. I mean with respect to track noise from the trains. The NYC subway is deafeningly loud! So I just wrote a letter to the TA asking why the subway is so noisy since it owns equipment to true wheels, weld and grind track, all the modern things.

I received a reply. But it answers a question I didn't ask. I asked, why is the NY subway so noisy? The question the letter answers is, what is the subway doing to reduce noise? And lets me know about the equipment to true wheels, weld and grind track, all the modern things.

So I still have a two parter: (1) Am I correct that the subway is quite noisy relative to other metros? (2) If so, why doesn't all the modern equipment the subway owns do a better job?

Paul,

First off, welcome to the site... I see you just joined recently and you've only posted a couple of times so far.

At first, I was going to blame New York's noise on the fact that New York's subway system is so old. But a check on Wikipedia (admittedly a quick one) shows the other cities you mentioned all had rapid transit in place before New York, with the exception of Prague, which opened its system in 1974.

I think a look at the history of New York's subway might help you find an answer. When the subways were first built, New York City was still growing, expanding outwards from Manhattan. Many areas of upper Manhattan and the Bronx were still somewhat "rural" until the subways made them accessible to the masses. At the very beginning, the subways were run by three, independent, commercial companies... all competing to get new lines built as quickly as possible. Speed was likely a bigger priority than noise control at the time.

On the other hand, cities like Paris and London had been established for hundreds (if not thousands) of years. I'm assuming (only because it's way too late at night for me to get into researching it) those cities had total control of their subways from the very beginning, and they probably had higher standards for noise control.

You might also take into consideration, the size of New York's subway system, compared to the others. Even if they were all very noisy at first, the other systems are smaller. It's much easier for them to perform a system-wide rehab which might use newer technologies to help to reduce noise in stations and on the trains themselves. New York City could never rebuild every single station or replace its entire fleet of trains overnight, or even in a year.

For example, Washington DC's Metrorail system has only a half a dozen lines, compared to New York City's 20+ lines. Metrorail was built decades later, when "science" knew more about how sound waves work... so stations were able to be designed to absorb the noise from passing trains.

The Metrorail also has a complete shutdown every night... giving crews a few solid hours every night where they can perform maintenance on tracks, stations and trains without worrying about disrupting service. By contrast, NYC's subway is running 24/7, so it's tough to pull off major projects that would require shutting down stations or portions of lines without inconveniencing many people.

Anyway, these are just my theories... could be right, could be wrong. But since the MTA sidestepped your question, I guess theories are all we can offer for now.

pnaw10,

I'm thinking your points about the size of the system and 24/7 operation might contain the answer. NYT can have the most sophisticated maintenance equipment in the world, but if the use schedule is every 12 or 18 months when it should be every 6 months (or whatever, I'm just using those numbers as examples), there will be more noise.

When the Manhattan Bridge's southside tracks opened again in 2000 (or around then) which allowed the resumption of long suspended express service on the Broadway line, I noticed how smooth the ride was, and quiet also. It's not like that now.

Isn't the noise caused by jointed rail, squealing brake shoes, and other miscellaneous? I thought that would be very difficult to quiet down. I rode the D.C Metro in early 2004 and I do not think it was noisy, but I really do not remember riding it too much.

How much noise does the 3rd rail produce (friction between shoe and rail)?

Boston's was pretty noisy from what I remember, and it actually makes the NY system look CLEAN (Boston had HUNDREDS of RATS in the South Station Red line stop). The DC Metro was DESIGNED with accoustics in mind. Just look at the underground station design, Acoustic tiles in every station, use of regenerative braking, and just the shape of the station vaults all help reduce the sound. In the tunnels it is ALL welded rail, and I beleive that they too were built with acoustics in mind. This is all from memory back 10 years ago when I "lived" there (DC) during most of the week, and commuted back home to NJ on the weekends.