From: jim bell <jimbell@pacifier.com>
Date: Tue, 13 Aug 1996 05:52:35 +0800
To: Bill Stewart <stewarts@ix.netcom.com>
Subject: Re: US Power Outages
Message-ID: <199608121716.KAA09849@mail.pacifier.com>
MIME-Version: 1.0
Content-Type: text/plain


At 11:02 PM 8/11/96 -0700, Bill Stewart wrote:
>At 06:15 PM 8/11/96 -0400, Dave Farber wrote:
>>attempt to explain that blackout and how to prevent such. We have not
>>progressed very far. The avalanche behavior of power systems is still not
>>well understood and techniques to prevent such failures are not obvious.
>
>It surprises me how little these systems appear to be monitored.
>It took some hours for them to decide that the brush fire on the
>California border didn't cause the system to shut down;
>you'd think they'd know quickly that the subsystem shut itself down
>or disconnected from the grid or whatever because of reason #17...


The story previously being promoted says that approximately at the 
Oregon/California border, a fire caused problems with the transmission line.

This morning, I read the new claim: extreme heat (presumably assisted by 
heat dissipated in the power line itself) cause the power cables near The 
Dalles (about 100 miles east of Portland, along the Columbia river) to 
stretch and sag, eventually shorting themselves out to trees near the ground.

I find this claim EXTREMELY hard to believe. The temperature coefficient of 
expansion of steel is about 10 ppm/degree C, which means that even if the 
power lines heated up 200 degrees C, that's only 2000 ppm longer, or about 
0.2%    I don't know the formula to determine the length of a catenary, and 
I'm too lazy to look it up right now,  but I'd imagine that this 0.2% 
increase in length won't increase the amount of sag by more than a factor of 
10 higher, or 2%.   That amount should be almost ignorable if the power line 
was competently installed and maintained.



>One of my concerns about the situation is that it's only a week
>or two after Clinton's speech about how The Government needs to protect the
>National Information Infrastructure for us.  I'm not paranoid enough
>to think that they did it, but I'm sure that within a week we'll
>see Al Gore or somebody making an NII Protection Agency speech
>and Louis Freeh explaining that we need enhanced wiretap underwriting
>to make sure that encryption-wielding hackers don't do it again.


I've long believed that if incidents such as these were the work of 
saboteurs, it is in the interest of the ordinary citizen that communication 
with those responsible is maintained.  If, on the other hand, the fact of 
the sabotage is covered up, that will only lead to more.  The government, on 
the other hand, has an illegitimate interest in seeing it hidden (where it 
can be hidden; and where the government can't see a good reason to publicize 
it), because if uncovered it would tend to force the government to actually 
deal with the dissatisfied citizenry: not merely the ones doing the 
sabotage, but also the ones who have heard what their motivations are and at 
least partly agree with them. 



Jim Bell
jimbell@pacifier.com