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From: bob@uhccux.UUCP (Bob Cunningham)
Newsgroups: comp.dcom.modems
Subject: Re: Lightning storms zapping modems [really LONG!]
Message-ID: <747@uhccux.UUCP>
Date: Wed, 19-Aug-87 12:59:18 EDT
Article-I.D.: uhccux.747
Posted: Wed Aug 19 12:59:18 1987
Date-Received: Sat, 22-Aug-87 02:11:51 EDT
References: <930@bc-cis.UUCP> <18600022@clio> <3587@sdcsvax.UCSD.EDU>
Reply-To: bob@uhccux.UUCP (Bob Cunningham)
Organization: U. of Hawaii, Manoa (Honolulu)
Lines: 90
Keywords: lightning power datacomm
Summary: postscript notes on the 1985 lightning strike

Some postscript notes on the 1985 lightning strike here at the U. of Hawaii.

No one ever figured out the total extent of damage, but it certainly was
in excess of $100,000 across the campus.  The Hawaii Institute of Geophysics
alone---where I'm responsible for various machines---documented $43,000
in damages for the claim on our multi-risk insurance policy (which,
very fortunately specifically included fire & lightning...your typical
insurance policy often specifically doesn't cover those).  That doesn't
include any of our DEC equipment which was replaced by DEC with no
questions asked (they were kind to us, if they went by the fine print
on their maintenance contracts, legally speaking they could have stuck
us with some hefty bills).  My guess is that HIG sustained about
20-25% of the damage on campus (the lightning striking just about on
top of us); if so, then the total campus damage ran around $200,000.

Again for HIG alone, over 40 terminals were damaged.  Almost half
of those we were able to repair by replacing 1488/1489 chips and such.
The remaining terminals were much more thoroughly fried and weren't
economically replaceable.  I don't know what the campus total of
damaged terminals was, but it was almost certainly over 100.

There were some indications that one or two computer sites may indeed
have suffered some sort of power surge, but the main damage was to
data communications equipment and devices attached to that equipment.
With several thousand datacom lines running around campus there were
lots of "antennas" that picked up induced currents.

We thought up all sorts of schemes to protect ourselves afterwards,
but really didn't implement any protection measures systematically.
The Meteorology department did a risk study which showed that the
probability of a similarly damaging lightning strike on campus
within the next 20 years was very, very small.  I hope they're right.

More (probably most now) campus terminals go through various port selectors
now, which means the port selectors protect most of the larger computer
systems from this sort of thing (our experience showed that replacing
parts of the port selectors was substantially cheaper than replacing
computer boards).  On the other hand, we're much more thoroughly
ethernetted on campus now and I don't have any experience with
lightning zapping ethernets.  One hopes that the transceivers
are the weak links.

Also on the other hand, we have many, many more PCs and fewer
computer terminals.  The PCs are more expensive to fix.

If we were in Florida or the midwest where lightning strikes such
as this were more common, we'd certainly take more systematic
protection.

1985 was not a fun year.  Several months afterwards we were hit
by a hurricane that knocked out the power grid on Oahu (and Kauai),
leaving Honolulu (the 11th most populous U.S. city) without power
for several days.  [during that time, hardly anybody was concerned
about their computers, being preoccupied by more immediate problems like how
to deal with the immediate shortages of water, gasoline and refrigerated
food---all very dependent upon electrical power].

Outlying areas were without power for several
weeks while the rest of us had to deal with rolling blackouts before
power generating capacity and major electrical trunk capacity
was restored.  We'd start up our computer systems when we had
power, and bring them down when the radio announcement came that
the power company was about to "roll" the power over to another
locality.

Utility electric power was generally "flaky" for
perhaps a year afterwards, with brief outages or major phase
imbalances occuring more than once a week.  HIG invested
in an UPS (uninterruptible power supply) for our main computer
systems.  Other University sites weren't so fortunate and
for various reasons wouldn't or couldn't obtain UPS's.

During that time an extraordinary number of power supplies and
various other computer components rolled over and died.  It was,
of course, virtually impossible to tie any specific failure to
the power problems we know we had during that time, but my personal
guess is that HIG alone probably saved the $40,000 or so we
spent for our 50kva UPS during the following year in equipment
that didn't fail because of power problems.

All of that is is the past now, and we generally don't worry too
much about these sorts of problems.  Although...once every few
months when we get an occasion power problem (particularly if
it's a surge of some kind) I can count on 1-3% of our various
models of PCs rolling over and dying (though it's usually just
the power supplies).

Bob Cunningham
Hawaii Institute of Geophysics, University of Hawaii
bob@loihi.hig.hawaii.edu