stationmaster
Crusty Old Geezer
Here's a link. Commuter train crash.
http://news.yahoo.com/s/ap/20090623/ap_on_re_us/us_dc_metro_train_derailment
Bob
http://news.yahoo.com/s/ap/20090623/ap_on_re_us/us_dc_metro_train_derailment
Bob
That's why commercial aircraft have redundant systems. Computer control is great...when it works. You can back it up with a simple track induction system, where the current in the track changes when you pass into a red block. No action in five seconds and the brakes are automatically applied just by dumping the air. I have no idea what type of braking system is used by the DC system but putting your faith in one system when you're running in automatic mode is foolish at best and, as we've seen, fatal at worst. Apparently this train set was about 30 years old and there's talk of some kind of brake failure. If that's the case, the DC Metro system has a lot of explaining to do. There's no reason a well maintained 30 year old trainset shouldn't operate flawlessly. The railroads have hundreds of 30 year plus locomotives running every day so age seems like a poor excuse to me.