Electronic components aging

Hi Spehro,

On 10/17/2013 8:56 AM, Spehro Pefhany wrote:
> On Thu, 17 Oct 2013 06:16:10 -0700, Don Y <this@isnotme.com> wrote:
>
>> Interesting situation to find yourself without *gas*.  Electricity
>> you aren't terribly surprised to find it "out" (though rare, here).
>> Losing water tends to raise eyebrows as it is REALLY rare.  Gas
>> even more so!  The only utility (interesting observation, this!)
>> that you *never* expect to lose is *phone* (land line).
>
> All this stuff will die fairly quickly (days) if there is a severe
> problem. If that ever happens, those folks affected are going to be in
> a world of hurt. Once the water supply fails, the wastewater treatment
> won't be far behind because it depends on a continous flow of water.

I'm curious as to how resilient our muni water supply is.  As most
of it is derived from wells scattered around the city, a *local*
outage typically takes out just one or two wells (e.g., there is
a well three blocks from here).  Presumably, the areas immediately
serviced by the "local well" can tap into excess supply in the
system -- though probably at reduced pressure in that local area
(I don't think the mains *into* an area are sized to truly support
the needs of that area; rather, to support the *surplus* water
SOURCED from that area!)

As we have no real "surface water" to speak of (there are a few
spots for folks who are willing to think *hard* about this), I
suspect a city-wide outage would leave us *all* without water.

(It's possible there is a dedicated backup line for each well pump
but I can't say for sure)

> This might be the real threat of EMP and the weapons (carbon
> filaments, smart bombs) that destroy electrical and water treatment
> systems- by taking out utilities over a wide area, people will start
> to die within weeks and they'll be in no mood to do anything but try
> to keep themselves alive.

People expect others to take care of them.  Amazing how UNprepared
(not UNDERprepared but UNprepared!) people are, in general.  As if
"it can't happen here".  :<  Folks are puzzled when they see lights
on in our house while *they* are experiencing a power outage...

I suspect when something dramatic happens, most folks will pile into
their cars and try to go <somewhere> in the hope that <someone> will
take care of them, there!  :>

(A friend is responsible for much of the state's disaster preparedness.
Each time we visit, I try to pick his brain a wee bit more for clues
as to what "they" think will happen -- not that I put much stock in
their assessments!  :-/  )

> I've never seen an unexpected loss of natural gas or water pressure
> (i.e. not due to scheduled repairs or maintenance). I imagine a water
> main bursting would result in a loss of pressure to some homes and
> businesses. Not paying bills might result in a sudden loss of gas
> pressure. ;-)

Water mains seem to break with some regularity regardless of where
I've lived.  Or, get "excavated" unintentionally ("Oooops!").

I've seen gas lines "dug up" twice in this neighborhood -- once by
a neighbor using a mini back hoe to install a new electric service
and playing too fast-and-loose with the "shared trench" that ALL
his services were routed through; another time when a construction
crew snagged the main on the other side of the neighborhood (and
frantically worked to obscure the Blue Stake markings so they could
claim the gas line wasn't marked!  :> ).  But, in each of those
cases, the supply to the neighborhood wasn't in jeopardy (electric
and gas services are "multiple feed", here -- not sure about other
utilities -- so even snagging a main just means that portion of
*that* main has to be pinched off)

> The last little bit of phone line is more prone to problems, IME. POTS
> must be 100-1000x more reliable than internet based services. OTOH, we
> have many options to POTS these days, so a single point failure isn't
> devastating.

But they also rely on power, etc.  I think a cell tower has ~5 hours
of backup capacity?  And, if there's an outage in a part of town,
then *all* the towers in that part of town "go silent" (eventually).

Consider the 9/11 experience, Katrina, etc. and how well we fared.
Interesting to consider how technology could be EFFECTIVELY deployed
in those scenarios.

E.g., a group I was affiliated with proposed creating "doctor-in-a-can".
Essentially, a doctor's examination room in one of those full sized
storage containers.  Examination table, X-ray, autoclave, generator,
water supply/purification, "supplies", etc.  The thinking being you
can put one on a truck and get them to a disaster area within hours
and "ship" the doctor from a third location.  More durable than a
"tent" and able to carry the heavy supplies that would be accessories
in a "tent solution" (e.g., large supply of water, propane, etc.)

I've mused over how to make phone service available to neighborhoods
while somehow constraining traffic (i.e., a portable cell tower
seems the ideal solution -- except "Gabby" will get on the line
and just yack away as soon as she gets through.  Any solution
that silently rations service will result in folks spending hours
just trying to make a call!)

Don Y wrote:
> 
> Hi Phil,
> 
> On 10/17/2013 7:09 AM, Phil Hobbs wrote:
> > On 10/17/2013 9:16 AM, Don Y wrote:
> >> Interesting situation to find yourself without *gas*.  Electricity
> >> you aren't terribly surprised to find it "out" (though rare, here).
> >> Losing water tends to raise eyebrows as it is REALLY rare.  Gas
> >> even more so!  The only utility (interesting observation, this!)
> >> that you *never* expect to lose is *phone* (land line).
> >>
> >> [Having lost it, once -- nearby lightning strike fried the electronic
> >> phones on our service -- it was really unnerving.  You just NEVER
> >> expect to lift the handset and NOT get dialtone!  Gotta wonder how
> >> many 9's in *their* availability figures!  :> ]
> >
> > NYC just finished the replacement for the 1917 aqueduct.  Big job.
> >
> > We've never had the gas or the water go out, but as far as phones go,
> > you live a very sheltered life.  We finally bailed on POTS, despite the
> > very great theoretical advantages of central-office power, because the
> > Verizon people we had to deal with were so uniformly incompetent.
> 
> I've lived in 5 different states and never had a phone issue aside
> from the lightning strike (in Colorado).  I had a flakey connection
> in Chicagoland, once -- but traced it to a length of cable that had
> fallen on the exhaust plenum for the gas furnace (the wire was nice
> and toasty-crunchy!  :> ).  Lots of *noise* on this (below grade)
> line in the days when I used a modem -- but that was traced to
> water migration in the buried cable.
> 
> In each case (save the Colorado one), I was still able to make and
> receive calls on the line.
> 
> As to the competence of the folks we have had to deal with "in the
> sales office", that's another story.  Took us *6* calls to get our
> DSL disconnected.  And, in the process, they managed to disconnect
> our *phone* as well!  (the 6th call was to get phone service restored).
> 
> Always nice to see the "this phone call may be recorded for quality
> purposes" come back to bite them in the ass, later!  :>
> 
> > Getting anything changed, or trying to get them to grasp the concept of
> > starting a home business and then moving to commercial space, took
> > several phone calls and at least a few hours of pain per time.  They
> > apparently had no method whatsoever for having one person understand
> > what the actual task or problem was, or even for making notes.  It all
> > had to be rehashed again each phone call, to a not-very-motivated and
> > not-very-bright listener.  I suppose that nobody who could find another
> > job would work there. (At one point we did find one guy who actually
> > cared, and knew how to get things done, but he worked on the other side
> > of their Chinese wall between commercial and residential accounts.)
> >
> > I eventually concluded that an organization that incompetent couldn't
> > really be relied upon to look after their central office batteries
> > either.  So we eventually changed to cable, and keep spare batteries for
> > our cell phones.
> 
> So, you've never actually LOST dialtone?
> 
> Neighbors routinely lose their cable service.  I wouldn't rely on it
> for a "reliable" connection.  A friend was recently spooked when she
> was having "chest pains" and found her cell phone unreliable -- and
> no "land line" alternative available!
> 
> And, we don't use cell phones (why have to own *two* phone services
> just to protect against *one* -- or both! -- being unavailable?)
> In some areas, TPC is replacing copper "land line" circuits with
> wireless.  Wanna bet they don't give the same availability levels??
> 
> You might find the folks who do the actual plant maintenance are
> of a different caliber than the sales droid/order takers (which,
> at least here, are located in another *state*!).
> 
> E.g., when I was having line noise problems, the tech that came
> out to check the line initially saw "good numbers" and was puzzled
> at the complaints I was making (I sat outside with him while he was
> checking the line).  He sat and watched the line for perhaps 15
> minutes before the noise floor shot up dramatically:  "Holy cow!
> Can you even *talk* on that line??"  (Yes, but a 56K modem can't!)
> 
> Of course, the only solution he had was to switch us to a different
> pair...
> 
> > The Verizon sales reps call at the office a couple of times a year to
> > ask me to switch to their service, and they're always confused when I
> > burst out laughing.


   About 15 years ago I called to report line problems. I was having to
scream to be heard over the noise. The woman had the balls to ask,
"What's the problem"?


   I have intermittent noise and hum on my phone line now. The wiring is
all new in the house, and I've used several different phones. I've seen
the line drop to four volts, with the phone on the hook.  This has been
going on for two years.  They have switched pairs, moved my number to a
different SLIC at their fiber to copper terminal a mile away and the
problem keeps coming back.


-- 
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

On Thu, 17 Oct 2013 10:57:39 -0700, Don Y <this@isnotme.com> wrote:

>
>Consider the 9/11 experience, Katrina, etc. and how well we fared.
>Interesting to consider how technology could be EFFECTIVELY deployed
>in those scenarios.

It's a much different problem to come up with ways to rapidly deploy
high-intensity relief to a limited area compared to dealing with a
lower intensity (but long-term serious) problem covering a wide-spread
area involving millions or tens of millions of people. We have
information on what that looks like (say Iraq in mid-2003) but there
is little first-hand experience of it in North America or most of
Europe. Military-style logistics (and admininstration) would probably
be required. How is grain going to get from storage to 1,000,000
people if several of the intermediate steps are "broken"? Most people
have enough food to last only days or maybe a week or two. 

>E.g., a group I was affiliated with proposed creating "doctor-in-a-can".
>Essentially, a doctor's examination room in one of those full sized
>storage containers.  Examination table, X-ray, autoclave, generator,
>water supply/purification, "supplies", etc.  The thinking being you
>can put one on a truck and get them to a disaster area within hours
>and "ship" the doctor from a third location.  More durable than a
>"tent" and able to carry the heavy supplies that would be accessories
>in a "tent solution" (e.g., large supply of water, propane, etc.)

Sounds interesting. They could be stockpiled in strategic locations
and deployed quickly. 

>I've mused over how to make phone service available to neighborhoods
>while somehow constraining traffic (i.e., a portable cell tower
>seems the ideal solution -- except "Gabby" will get on the line
>and just yack away as soon as she gets through.  Any solution
>that silently rations service will result in folks spending hours
>just trying to make a call!)

Too bad cell phones don't have a mesh net function! 

Hi Spehro,

On 10/17/2013 11:35 AM, Spehro Pefhany wrote:
> On Thu, 17 Oct 2013 10:57:39 -0700, Don Y <this@isnotme.com> wrote:
>
>> Consider the 9/11 experience, Katrina, etc. and how well we fared.
>> Interesting to consider how technology could be EFFECTIVELY deployed
>> in those scenarios.
>
> It's a much different problem to come up with ways to rapidly deploy
> high-intensity relief to a limited area compared to dealing with a
> lower intensity (but long-term serious) problem covering a wide-spread
> area involving millions or tens of millions of people. We have

Yup.  But the two tend to go hand in hand -- the short term "acute"
problem followed by the longer term "chronic" problem.  *Before*
people realize they're screwed, they grasp for the amenities that
they have become accustomed to (i.e., "why can't I make a phone call?")
Once that initial "event" has been absorbed, then they worry about
survival.  Once *that* looks like it is addressed (however well or
poorly), they find themselves bored and wanting some of those
amenities, again ("There's nothing on TV", "My phone doesn't work",
etc.)

> information on what that looks like (say Iraq in mid-2003) but there
> is little first-hand experience of it in North America or most of

I suspect Iraqis were better able to cope than Americans would be!
Too big a hit to their standard of living coupled with a general
lack of self-reliance.

> Europe. Military-style logistics (and admininstration) would probably
> be required. How is grain going to get from storage to 1,000,000
> people if several of the intermediate steps are "broken"? Most people
> have enough food to last only days or maybe a week or two.

I don't think most people can make a full week.  And, would probably
be distressed that they couldn't eat *what* they wanted ("Chicken
AGAIN??").

Lots of LDS'ers, here.  Presumably, part of their religious practices
includes preparing for the end of days -- stockpiling food, etc.
(I think supposed to have 1 year of food on hand.  This is "policed"
to varying degrees, apparently!).

The tongue-in-cheek reply when confronted with the "what would you
do in the event of a prolonged national disaster" is:  "find an LDS
family"!

I think the more realistic (and probable!) problem is a short term
disturbance.  Say 3 to 7 days in duration.  Of course, you wouldn't
necessarily know how long this was going to be at the onset.  But, I
see most folks would immediately step to the "evacuate" or "plunder"
response.

(We have BoB's prepared for shelter-in-place, drive-out, and hike-out
scenarios.  In the last case, having the bags packed so we can quickly 
shed supplies/weight if only one of us is able to carry any load.  I'm
sure none of our neighbors have even considered these possibilities!
E.g., CB radio, handhelds, flint, first aid, clothing, maps, radio,
solar/mechanical chargers, inverters, meds, etc.)

>> E.g., a group I was affiliated with proposed creating "doctor-in-a-can".
>> Essentially, a doctor's examination room in one of those full sized
>> storage containers.  Examination table, X-ray, autoclave, generator,
>> water supply/purification, "supplies", etc.  The thinking being you
>> can put one on a truck and get them to a disaster area within hours
>> and "ship" the doctor from a third location.  More durable than a
>> "tent" and able to carry the heavy supplies that would be accessories
>> in a "tent solution" (e.g., large supply of water, propane, etc.)
>
> Sounds interesting. They could be stockpiled in strategic locations
> and deployed quickly.

Exactly.  Similar to the way rapid response meds/agents are
stockpiled locally.  If *all* you have to do is "say go", its
a lot easier to get this sort of aid to a location than if you
had to round up all the supplies, arrange shipping, find a
contact person on the other end, etc.

("Put this on the truck.  Start driving to Feenigs.  We'll call
you with the final destination and your contact person before you
get there.")

>> I've mused over how to make phone service available to neighborhoods
>> while somehow constraining traffic (i.e., a portable cell tower
>> seems the ideal solution -- except "Gabby" will get on the line
>> and just yack away as soon as she gets through.  Any solution
>> that silently rations service will result in folks spending hours
>> just trying to make a call!)
>
> Too bad cell phones don't have a mesh net function!

The problem with cell phones is people think of them as "theirs".
I suspect people would be unwilling to allow their phone to be used
as a relay -- unless they were actively talking on it!  I think this
would be exaggerated in the event that power was in short supply
and folks tried to economize on their battery life!

I originally thought a suitcase into which cheap *wired* phones
(handsets) could be connected.  That way, someone could oversee
fair use of the resource.  And, allow people to "register"
themselves at a particular "suitcase" so folks could relay messages
back to them at that suitcase (check in tomorrow to see if you
have any messages waiting).  Power it off a car battery (*any*
car) while still *in* the car.

The more realistic solution is to allow cell phones to connect to this
suitcase. But, then you need some way of rationing the service so
folks don't just treat it like "normal" telephony.

You would also find yourself inundated with requests for folks
to "charge their cell phone battery".  This goes away if *you*
provide the handset...

It's an interesting problem.  But, not one that *I* have to address!
<grin>

On Tuesday, October 15, 2013 5:50:39 AM UTC-5, Piotr Wyderski wrote:
> Speaking of high reliability... I think that it is often
> 
> a somewhat neglected issue, so I start this thread as a
> 
> mean to collect *practical* observations for people who
> 
> care about long MTBF. In other words, "if I had to build
> 
> a device which should last 50 years, I would... what?"
> 
> 
> 
> Resistors (if not overloaded): immortal
> 
> 
> 
> Ceramic capacitors: as above
> 
> Tantalum/nobium caps: ?
> 
> 
> 
> Electrolytic caps: disaster area
> 
> 
> 
> Transistors, diodes and ICs: the silicon die should not
> 
> degrade, but how about the endurance of the resin?
> 
> At least some early Polish ICs had problems here:
> 
> the thermal coefficient of the casing was not well-matched
> 
> and power cycling finally broke the bonding wires.
> 
> There were some moisture absorbtion problems, too.
> 
> Is it still an issue?
> 
> 
> 
> BGA: it can be expected that thermal cycling will
> 
> eventually destroy the balls, as there are no "springs"
> 
> to absorb thermal stresses. Gull wings are much better here.
> 
> 
> 
> FR4: ?
> 
> 
> 
> Soldering: the EU has done a lot in order to make
> 
> the newer devices not very reliable as a consequence
> 
> of the RoHS directive. I see nothing wrong with the
> 
> old SnPb joints, the old boards look healthy.
> 
> 
> 
> Conformal coating: ?
> 
> 
> 
> Wires: ?
> 
> 
> 
> Please add your comments.
> 
> 
> 
> 	Best regards, Piotr

I have nothing to add to the list, but this subject remind me of this old "electronics glow"

http://www.dailymail.co.uk/news/article-2004797/Worlds-oldest-light-bulb-110-years-old-Livermore-California-station.html

All of Des Moines Iowa had water shut off in 1993 because
flood water overtook the water treatment facilities.
Emergency broadcasts told people to fill water
containers in the last hour of water service.
Then it was shut off.
Early reports were that it would be undrinkable
for THREE or FOUR months, but Army Corps
of Engineers helped with a process
called shock chlorination.
Megadose of chlorine made the water OK for
flushing toilets and not much else, then
eventually it was suitable for showers and
washing hands, and eventually it was back
to being approved for drinking within only
one month of the flood shutdown.
 
I assume that gas/electric and some
telephone land lines went down in
areas inundated with water.
 
In Cedar Rapids Iowa in 2008 the flood
didn't quite shut down the water plant
though they had to shut off some of the
wells and had a reduced capacity.
 
Before the water came up, the gas company
ran around in the areas projected to
be flooded (500 year flood plain)
removed every gas meter and capped the pipes.
 
Electrical utility pulled the meters,
shutting off power in those areas also.
 
Pulling that many power and gas meters must
have been a bizarre job.
 
Some people were angry about electricity
being shut down since they were running
pumps to pump out their basement.
 
Ironically, pumping out your basement
backfires disastrously, causing basement
walls to be forced in (collapsed) by
force of water outside in the soil.
Letting the basement fill with water
counteracts the outside water pressure
that collapses basement walls.
 
Collapsed foundations/basement walls
was the most common thing that
made the difference between a home
being repairable or not, for cost reasons.

On 2013-10-17, Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote:
> On Thu, 17 Oct 2013 06:16:10 -0700, Don Y <this@isnotme.com> wrote:
>
>>
>>Interesting situation to find yourself without *gas*.  Electricity
>>you aren't terribly surprised to find it "out" (though rare, here).
>>Losing water tends to raise eyebrows as it is REALLY rare.  Gas
>>even more so!  The only utility (interesting observation, this!)
>>that you *never* expect to lose is *phone* (land line).
>
> All this stuff will die fairly quickly (days) if there is a severe
> problem.

BTDT (feb 22 2011)

> If that ever happens, those folks affected are going to be in
> a world of hurt. Once the water supply fails, the wastewater treatment
> won't be far behind because it depends on a continous flow of water.

> This might be the real threat of EMP and the weapons (carbon
> filaments, smart bombs) that destroy electrical and water treatment
> systems- by taking out utilities over a wide area, people will start
> to die within weeks and they'll be in no mood to do anything but try
> to keep themselves alive. 

If the roads are still working water (for drinking etc) can be trucked 
in (in tankers) and distributed by hand. 

> I've never seen an unexpected loss of natural gas or water pressure
> (i.e. not due to scheduled repairs or maintenance). I imagine a water
> main bursting would result in a loss of pressure to some homes and
> businesses. Not paying bills might result in a sudden loss of gas
> pressure. ;-) 

I've heard of two events close enough to make the news, but never
been effected.  no gas here.

> The last little bit of phone line is more prone to problems, IME. POTS
> must be 100-1000x more reliable than internet based services.

I've had the phone go out 5 times and the ADSL go out three times,
ADSL will still work on a shorted pair.

-- 
&#9858;&#9859; 100% natural

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

On Tuesday, October 15, 2013 3:50:39 AM UTC-7, Piotr Wyderski wrote:
> Speaking of high reliability... I think that it is often
> 
> a somewhat neglected issue, so I start this thread... "if I had to build
>a device which should last 50 years, I would... what?"
> 
> 
> 
> Resistors (if not overloaded): immortal

Not if you include carbon film or carbon composition; with any HV applied,
the corrosion of C into CO or CO2 is a killer.   The screen resistors on 
old TVs (had about 2-4 kV on them) were notorious for failing open.
The E-field around the component would attract any ions (like, from ozone).
 
> Electrolytic caps: disaster area

Maybe, maybe not; there are solid-electrolyte electrolytics that have
very good aging (and the old MIL tantalum/silver things have a reliable
chemistry).
 
> Transistors, diodes and ICs: the silicon die should not
> degrade, but how about the endurance of the resin?

Alas, breakdown voltage of bipolar transistors goes down (and frequency
of operation goes UP) with age.  Some diodes  (LEDs) have
surface-related contamination  issues, there's lots of complaints
about rotary encoders that result from them going dim with time.

Cosmic rays can kill a MOS oxide, there were also faults due to
natural radioactivity in ceramic RAM packages.   Not to mention,
there's ICs using stored charge in little floating capacitors to
trim thresholds, those stored charges WILL leak.

On Sat, 19 Oct 2013 13:58:30 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

>On Tuesday, October 15, 2013 3:50:39 AM UTC-7, Piotr Wyderski wrote:
>> Speaking of high reliability... I think that it is often
>> 
>> a somewhat neglected issue, so I start this thread... "if I had to build
>>a device which should last 50 years, I would... what?"
>> 
>> 
>> 
>> Resistors (if not overloaded): immortal
>
>Not if you include carbon film or carbon composition; with any HV applied,
>the corrosion of C into CO or CO2 is a killer.   The screen resistors on 
>old TVs (had about 2-4 kV on them) were notorious for failing open.
>The E-field around the component would attract any ions (like, from ozone).
> 
>> Electrolytic caps: disaster area
>
>Maybe, maybe not; there are solid-electrolyte electrolytics that have
>very good aging (and the old MIL tantalum/silver things have a reliable
>chemistry).

The silver-cased wet-slugs tended to corrode from the inside. I think
the dry tantalums were pretty good.

Wet aluminum electros diffuse out water and dry up. Polymer aluminums
diffuse *in* water and fail.

Can't win!

> 
>> Transistors, diodes and ICs: the silicon die should not
>> degrade, but how about the endurance of the resin?
>
>Alas, breakdown voltage of bipolar transistors goes down (and frequency
>of operation goes UP) with age.  Some diodes  (LEDs) have
>surface-related contamination  issues, there's lots of complaints
>about rotary encoders that result from them going dim with time.
>
>Cosmic rays can kill a MOS oxide, there were also faults due to
>natural radioactivity in ceramic RAM packages.   Not to mention,
>there's ICs using stored charge in little floating capacitors to
>trim thresholds, those stored charges WILL leak.

Intersil makes voltage references that are essentially charged
floating capacitors with follower opamps. They would make good
radiation detectors.


-- 

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro   acquisition and simulation

On Thu, 17 Oct 2013 08:32:15 +0100, Paul E Bennett
<Paul_E.Bennett@topmail.co.uk> wrote:

>
>>>Any component that relies on the long term stabiliity of chemistry =
will
>>>degrade and fail eventually.  Even in the mechanical world metals like
>>>Iron and Stainless Steel will change over time.
>>>
>>>Only in software can you achieve really long lifetimes (if you are =
careful
>>>about your design) but then what would you have left to run it on?
>>=20
>> Try looking at some serious long term infrastructure systems.  There =
is
>> plenty of SCADA that has already lasted as much as 60 years or more.  =
Lots
>> more in heavy industries (refining, major metal mills, chemical =
plants,
>> water treatment, wastewater treatment, etc.,) where replacement costs =
get
>> really really big.
>>=20
>> ?-)
>
>I don't suppose that those systems are still running without having had =
some=20
>maintenance (board swaps, repairs etc). Would you wish to guarantee that=
 any=20
>system you design today will still be operating that far in the future.
>
>I don't know where your utilities are based but I am certain that the =
ones=20
>near me have all upgraded their systems over the years (just to cope =
with=20
>demands).

Here we get into some of the interesting parts.  They do not replace
working gear without a really good reason.  Particularly if it involves
major investment in compatible equipment in some way.  Face it, =
rebuilding
refineries and such is very expensive.  And generally not done even
piecemeal.

?-)