Quote:
Originally Posted by Kev0607
I was reading on some other forums, just as you mentioned pollution & I come across something that I'd like to mention to you...
Many people travelling on the underground in London claim to have black tissues when they blow their noses. A lot of that is brake dust from the trains when they slow down & its also due to the high levels of iron in the tunnels. Some even claimed that it got onto their clothes, like white shirts were getting dirty around the collars & cuffs! 
Breathing that in a confined space can't be good! |
I daresay there's a lot of carbon in it as well - fairly sure brushless motors are a relatively recent thing and therefore i would expect most of the electric motors powering the underground trains to be brushed - carbon is the common material for them.
Must admit though, i've never looked into the motors for electric/underground trains - they may be brushless these days but i daresay historicallly the had brushes.