That was such an insane thing to discover my first time on the BART. I’m sitting there thinking a catastrophic accident is about to occur, but everyone else is just on their phones... oh, that’s just the screech!
From a Londoner's perspective, this is giving me tortured flashbacks to travelling on the Jubilee Line. It's physically painful to hear once you start speeding up inside the tunnels.
I travel on the Northern line on the London Underground to get to work and the sound of the trains nowdays hits 100dBA or more of extremely loud screeching: https://i.imgur.com/04YwBHJ.png
I went as far as lodging an official complaint and was told that to deal with capacity trains are running more often and faster than they have in the past, hence the increased noise. Furthermore due to the Northern Line having been built before environmental noise regulations were passed, it's exempted so Transport for London aren't planning on doing much about it.
At the risk of sounding like a curmudgeon - between always on ear buds and mass transit noise we're risking a generation of kids suffering hearing loss well before their time.
My understanding was that all rail systems since roughly forever use tapered wheels. Primarily to reduce wear, by having the tapered wheels self center instead of grinding against the track.
It's really odd that they seem to just roll that out in 2017?
> unlike the cylindrical profile which again just steers with the flange basically rubbing against the edge of the railhead.
That's crazy. That means that the wheels are actually slipping when going around a corner, because the wheels are all the same diameter. Unlike conical wheels, which are essentially self-steering.
How could the BART trains possibly have cylindrical wheels? Conical wheels have been used on trains for ages, so that's seems weird. But doing some research, it seems that, yes, they were cylindrical:
> Queensland Railways, for its first hundred years, used cylindrical wheels and vertical rails. With non-inclined rails and cylindrical wheels, the wheel squeal from trains taking curves on that railway was slight. After adopting coned wheels and inclined rails from the mid 1980s, the wheel squeal from trains curving at the same location and at the same speed decreased immensely. Some modern systems, such as Bay Area Rapid Transit (BART) in San Francisco, use cylindrical wheels and flat-topped rails; BART is now switching to conical tread to reduce the noise caused by flange/rail contact and loss of adhesion of one of the wheels on curves.
"BART says", but as of 6 months ago I was compelled to buy ear plugs for my commute. There's a stretch just before West Oakland (Westbound) that I'm near certain has given me ear damage.
Did you watch the videos, specifically of the guy in what seems like a golf cart going over the walking section of the bridge? It sounded horribly loud, louder than the guy who was crying about how loud it was
The bart didn’t do that when it was new. Apparently, standard railway maintenance involves grinding busy tracks down on a regular basis (so the track has a round crown on top instead of being flat).
Of course, the BART system simply fails to do the maintenance. I used to commute through the transbay tube and would happily join a class action suit over the hearing loss.
