W6KWF > TECHNI 03.10.21 20:00l 56 Lines 2552 Bytes #999 (0) @ WW
BID : 09745_W1XSC
Subj: Scattergood-Olympic Line 1/7
Sent: 211003/1742z @:W1XSC.#NCA.CA.USA.NOAM [Santa Clara Co] #:9747 $:09745_W1X
I've always loved this story, and Grady from Practical Engineering
recently posted a video on YouTube which reminded me of this magnificent
story of repairing a underground power transmission line with some more
details than in the original post in 1989.
- Kenneth, W6KWF
Date: Wed, 27 Sep 89 10:27 PDT From: "Thomas L. Mc Mahon"
<email@example.com> Subject: Cuts and jumpers (on a
To: Hardware@riverside.scrc.symbolics.com [Not quite the right mailing
list but close. If you don't care about megawatts, bus bars bigger than
your wrist, things that cause ground loops out to Hawaii, or big hairy
construction projects hit D now.]
Several days ago a very large number of trucks and men from the Los
Angeles Department of Water and Power descended on my neighborhood. They
removed large sections of Pershing drive to a depth of 15 feet or so
over a stretch of about a city block. I assumed they had a problem with
a water main or something.
When they started building semi-permanent structures over the holes I
knew something really big was up. When the large trucks full of strange
power tools, mega-welding machines, breathing equipment, and racks of
test equipment came I started wondering. Driving by a couple nights ago
(11 PM), I noticed that the pace hadn't slowed - they were at it 24
hours a day.
My curiosity got the best of me yesterday when they brought in the giant
tanks full of liquid nitrogen. LN-2 for the DWP? I parked my car and
played the lookie loo.
It turns out they have a problem with an underground wire. Not just any
wire but a 230 KV, many-hundred-amp, 10 mile long coax cable. It shorted
out. (Lotta watts!) It feeds (fed) power from the Scattergood Steam
Plant in El Segundo to a distribution center near Bundy and S.M. Blvd.
To complicate matters the cable consists of a copper center conductor
living inside a 16 inch diameter pipe filled with a pressurized oil
dielectric. Hundreds of thousands of gallons live in the entire length
of pipe. Finding the fault was hard enough. But having found it they
still have a serious problem. They can't afford to drain the whole
pipeline - the old oil (contaminated by temporary storage) would have to
be disposed of and replaced with new (pure) stuff which they claim takes
months to order (in that volume). The cost of oil replacement would be
gigantic given that it is special stuff. They also claimed the down time
is costing the costing LA $13,000 per hour. How to fix it and fast?
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