Posted on 06/23/2009 5:30:04 PM PDT by normanpubbie
WASHINGTON – Investigators looking into the deadly crash of two Metro transit trains focused Tuesday on why a computerized system failed to halt an oncoming train, and why the train failed to stop even though the emergency brake was pressed.
At the time of the crash, the train was also operating in automatic mode, meaning it was controlled primarily by computer. In that mode, the operator's main job is to open and close the doors and respond in case of an emergency.
Debbie Hersman, an investigator with the National Transportation Safety Board, said it was unclear if the emergency brake was actually engaged when Monday's crash occurred. But the mushroom-shaped button that activates it was found pushed down in the operator's compartment.
(Excerpt) Read more at news.yahoo.com ...
Computers failing should NEVER be enough to cause a train accident. What kind of piss poor design is this?
WMATA is always claiming they don’t have enough funds.
Bet they have plenty of useless bureaucrats though.
yeah, the driver’s i-pod was taking too long and she forgot to do something..
Was the operator texting again?
No, the mushroom shaped button was just an input to the computer.
I hear there are lots of industrious
Chinese programmers engaging in
Internet hacking
One wonders if someone got onto the
Computer servers running the subway system
Nah,
I would never happen
Blue Screen of Death?
The button was probably pushed down because the operator was thrown against it after the train had already hit the one in front of it. Pushing the emergency brake button after the incident has already happened doesn't usually do much to stop the accident from happening in the first place. It does however act as a nice shield for the operator to hide behind and deflect blame.
Subway buff info:
The Washington DC metro is computer controlled (as is the SF BART system). The train operator doesn’t normally “drive” the train. His/her job is to open and close the doors and to provide a “presence” in an emergency situation. On the older systems (NYC for example) the train operator does “drive” the train, although there is a “failsafe” signal system which can stop the train in the event the train operator becomes incapacitated (drops dead of a heart attack while the train is in motion etc.).
You are so right. When ever Human lives are at stake they're should be redundant systems. Just like in Aircraft.
Heh. If so, that's a fundamental design error, forbidden by ALL written codes for design and construction of control systems. Emergency anything is supposed to operate whether or not the computer is even there.
Yep. When the downside risk is serious personal injury or death, common design practice includes redundancy; where the redundancy is outside the computer.
For example, if safety is obtained by opening a power circuit, then redundancy is two sets of power contacts in series, so if one sticks closed, the other opens the circuit.
My guess is yes. Investigators will be looking at cell phone and texting records.
One DC Metro source says the trains run on automatic, another says the trains were all being operated manually at that time.
If this event wasn’t hacker/terrorist, the next one certainly will be.
Now that a weakness has been revealed, the hackers will exploit it.
Piss-poor design is Washington, D.C.’s middle name.
They said there was heat discoloration on the rotors indicating the the brakes were activated at some point. When and how long is another story.
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