Noise reduction with trains is probably best done with improving the trains. I live next to a frequent trainline, so I can say:
There are modern long electric passenger trains, that barely make a noise at all. And then there are old freight trains, that can be heard from miles away. Since I doubt this noise barrier will be placed everywhere except at some very special key areas, I rather want the Bahn to focus on better trains in general.
For intercity trains it doesn't matter what the propulsion method is though, since every train will make a lot of noise at speed. It's improved with aerodynamics and better wheel / tracks, but ultimately noise will be an issue. Consider also cars where at speed the noise is not due to the engine, but to wheel / road noise.
I live outside the city, so I know the difference in sound at high speed when they pass by. It makes a great difference. Combustion vs electric but also the manufacturing and damping of the wheels etc.
I used to live by rails with a small incline, and the diesel locomotives made a loud low noise accelerating uphill from a station, while downhill the trains moved far faster and the engines were quite insignificant compared to noises due to speed: mainly the wheel noise and going over the expansion joints.
huh. rubber on asphalt is very loud on high speeds, could steel on steel really be quieter? (for downvoters: this is a real question, I'm not trying to suggest it can't be)
Yes, because rubber and asphalt do not really have a smooth surface unlike polished steel. So all the little bumbs give your car grip, but also cause friction, which is noise.
One of the reasons, why trains are better suited in theory for long distance transport, than trucks. Little friction, so more energy efficient.
Rolling stock lives for many decades and replacing it early is cost prohibitive. So I don’t think changing something about the trains is the best option for reducing noise.
„Can be heard“ is not the problem we’re trying to fix, and no reasonable amount of engineering can fix that . Maybe if you converted everything to maglev and limited speeds to 20mph.
What evidence other than your anecdotal evidence that a lightweight passenger train creates less noises then a heavy load freight? I am sure there are some differences in regards to design and age but wouldn't you imagine the majority of the difference is in weight? Passenger trains weigh nothing.
A bit more than that. And old freight trains are loud, even when empty.
Another example, there is a small local passenger train with a combustion engine. Very loud, whether slow or fast. Unlike the mentioned modern electric one from Alstom, who are so silent, that they are dangerous when they pass by a train station and you are too close to the track. You only notice them moments before they wooosh by.
And if you want more than my anecdota of everyday experience, there are tons of youtube videos of different trains to see that trains can be loud, if that was not a manufacturing concern, or silent. Usually, the older the louder.
I think you missed my point, my fault. Passenger trains and individual train cars do indeed weigh considerably less than fully loaded freight. So yes....its not nothing but they are easily double the weight. Leading to my point that when you are 2.5x+ the weight, its a different engineering problem along with an issue of economics.
Freight cars are not loud only because of age but also because of weight and the challenges on both engineering and cost to remedy it. It is hard to compare a passenger train with a freight train, entirely different beasts.
"It is hard to compare a passenger train with a freight train, entirely different beasts."
Hm, for me they are quite simimlar. Just one was build to be more silent mainly for passenger comfort (it is inded nicer in the modern silent ones) and the other for most weight. But you could optimize freight trains for silence as well. All the loud metal scratching noises for example are avoidable, even with more weight. The ones I am talking about were just not build with noise in mind.
Just adding my own data:
I’ve been living next to a train station for a few years now, I’d say that freight is insanely more noisy than passenger trains, 100% of the time.
I live in France btw, so it’s all electric trains.
There are modern long electric passenger trains, that barely make a noise at all. And then there are old freight trains, that can be heard from miles away. Since I doubt this noise barrier will be placed everywhere except at some very special key areas, I rather want the Bahn to focus on better trains in general.