newfag here, i live far away from any metro city so i don't know anything about /n/ stuff
i came back from a visit in italy
there was this subway train in Rome which sounds like "AYYYYY LMAO" evrytime it starts or stops.
where does this noise come from? it is electric so it should be silent
>>937341
https://www.youtube.com/watch?v=1tk1Bm5xcA8
That noise in which you are hearing is "presumably" from the unit's traction motors, used by most rail vehicles of this era for propulsion.
Some are louder than others, and some are more "alien-like" than others.
https://www.youtube.com/watch?v=Hu_1JM_UiuA
rectifiers/frequency modifiers create audible vibration when converting 750 V DC to 3-phase AC needed by modern traction motors. As the frequency of the 3-phase motor has to be increased with the rotational speed, you get nice sounds such as here https://www.youtube.com/watch?v=4Ky7t6l0WcU
>it is electric so it should be silent
Said who?
https://www.youtube.com/watch?v=Yyh5OPaqouI
Inverters.
Some of them sound amazing. I don't know why I love their sounds so much.
Example of a Hitachi VVVF inverter on a JR East E231 (from outside)
https://www.youtube.com/watch?v=8yw5NDHBlv0
And the same train from inside:
https://www.youtube.com/watch?v=neCSgzFUkkc
A siemens inverter nicknamed the "Do Re Mi Fa" inverter, for obvious reasons:
https://www.youtube.com/watch?v=YUux8rFoK00
>>937666
Neat videos. I've only been on a train once in my life.
>>937668
American?
>>937671
Yeah, south Florida. Rode Tri-Rail between Fort Lauderdale and Miami.
The view from the window was beautiful though. So much amazing graffiti on the buildings near the tracks.
