Why do trains make interesting sounds

If you have any questions, leave a comment below.

Here are some videos that I recommend you watch to understand it better...

[TheAngelsHaveThePhoneBox]

The Siemens Taurus locomotives make the absolutely best sound of all trains. It literally plays a musical scale while accelerating from a stop. There are countless videos of it on YouTube.

[EonityLuna]

I always felt that a train’s motor sounds made up a part of its “identity”, and I also kinda wondered how the sounds are made. I know part of it is due to electromagnetically-induced noise (coil whine), but I always wondered why even the same type of motors might sound different when they are from different manufacturers, etc.

This video definitely provides a good overview of what I always wanted to know.

[edmund-osborne]

This is a brilliant video! I was always wondering why electric trains make that sound! I personally love motor noise. My favourite motor noise comes from the Siemens Taurus, Class 455, Class 323 and Desiro.

[tractioninverter]

The synchronous (pattern based) mode is used to reduce motor current harmonics. The method is called "Selective Harmonic Eliminated PWM" or just "SHEPWM". And you are right, the transition between patterns is because of the limited maximum switching frequency - very well explained!
For asynchronous carrier based modulation there are many methods. More common nowadays is the Space Vector Modulation (because it creates less current harmonics) and in older drives you would find 'center-aligned' or 'edge-aligned' SPWM methods. All of these carrier based modulation methods can be used with a random generated carrier in a given range to reduce harmonics even further.

[forzabowe]

The 1996, and 2009 stock makes the nicest noises

[sonicthefreedomfighter]

I like that sound the jubilee line 1996 stock makes.

[johnstefanis]

These sounds, I must say, for some reason I find them so satisfying : D

[buddyclem]

6:00 Those DC motors sound so beautiful. Outdated technology? Yes. But I don't care. It is a thing of beauty. Those newer trains that make a high-pitched sound drive me a little crazy. I understood the electrical part, but now I know why the different drive systems sound different. Thanks, Beno!

[peterudbjorg]

Brilliant video! I’ve had a slight grasp of the idea of pulsing (I’m a tram driver, and we have gone from resistors to transistors (still DC, two types) to AC technology. The DC I understood, but have never had the AC principle explained so easily.
However: Early single-phase electrificiation used low frequency AC. The Thamshavn–Løkken Railway uses 25 Hz, and the Norwegian/Swedish/German railways uses 16 2/3 Hz. I’ve been told they use DC motors somehow converted to AC, and the low phase prevents arcing (they are still using brushes and coiled rotors).
50 Hz could not be used until transistors came along, before then they used converters (rectifiers), such as the Ignitron (a kind of mercury arc rectifier), before reliable solid state rectifiers came along.

Details about this are in the book "The history of the electric locomotive" by F. J. G. Haut (aviable in libraries and on Amazon).
For which reason many railways electrified with direct current (France, Belgium, The Netherlands).

More detalis are to be found in the book "Electric traction on railwas" by Philp Dawson, but this is a rather old and rare book.
Keep up the good work! :D

[wdavem]

Fantastic video! I've ridden on many of those types of trains over many years and gradually figured much of this out but it's great to see so much more. I witnessed a 1990's BART train blow a motor and drive as it was slowing down nearing a stop; I was in the station and there was a very very loud BANG the instant the descending tone switched to the final continuous drive tone; which I thought was most interesting. Within about a minute half the station was full of a thick, white yet nearly odorless smoke. I figured that transistor based drive and maybe some motor coil had met it's 1000 volts of instant DC death.
Regarding the advancement of transistors, it seems the same thing is true for other types of motors. I work with old video tape machines and have noticed some very interesting and sometimes complicated methods of getting tapes to run at high (yet servo controlled) search speeds in the more expensive machines. I think I am hearing about 200 Hz as the maximum the coil switching speed in some of these capstan motors with parts originally designed in the early 1980's. When the machine is commanded to run at a slightly faster search speed the capstan motor just disengages and the machine switches to servo control of the direct drive dc reel motors (on some older machines). I'm guessing that is a duty cycle of less then 400 hz or so.

[dykodesigns]

Now I know why trains make the noises that they do. Remember those double deck train in the netherlands from your amsterdam video's? They have a characteristic woop-woop sound that's a bit like the examples you've shown. The really old (now out of service) mat 64 trains from the 1960's had some characteristic sounds, they accalerated quickly but could also break quite fast making a sound that I've associated with the sound of waterfall. These trains also made you feel every shock of the rails like those old prague trains. Those Mat 64 trains where awsome.

[godfreypoon]

I thought it was because they recycled parts from the war of the worlds tripods.

[HesterClapp]

This video was very interesting and brilliantly explained! Could you please reference some of the sources of information you used to make it? I would love to research this topic in more depth!

[mattegeniet]

I started going down this rabbit hole after riding Helsinki metro trains from late 70s/ early 80s. Learned they were apparently the first trains ever to use this technology and it’s really loud and very obvious compared to 90s trains. I really thought they had a gear box or something!

[Satters]

Back when I was studying Electrical Engineering at college, we spent months on DC motor drives, I still prefer Motor Generator sets rather than modern static converters, you can see and hear real engineering.
Unstable electronics no thank you, give me the logic of a few thousand relays any day :)

[SproutyPottedPlant]

I guess that's why you can reduce that frequency to make lifts sound nice.

[sgbuses]

Thank you for making this - it is so underrated despite its importance, because even I have missed this video this first time round. If you have the time, are you able to make a video comparing how much power consumption is saved/used relative to each generation of technology used on trains (resistor - chopper - thyristor - GTO - IGBT - MOSFET)?

[Cloudrak]

I wish one day that one person makes an electric car with 90s pulsing patterns.

[trashcan]

I recently started riding the Metra Electric into Chicago and I’ve been really curious about this. Thank you sir 🫡

[dfn]

I have heard that sound on few modern trains too.