John Dulak wrote:
On 3/29/2019 12:17 AM, Paul wrote:


The only problem with the cell tower idea, is I don't
think anyone has a plan, to drive around to all the
cell towers and fill up the tanks, if there is an
extended outage. They're still probably depending
on the power coming back, relatively quickly.

Paul

Paul:

Many emergency generators run on natural gas from a utility company.
This is available mostly in more densely populated areas so the cell
towers would stay up for a lot of users. Out in the boondocks - who knows.

John

My home is heated by natural gas.

I think they like the comfort of having
a captive tank full of diesel for the job.

Same with the sewer pumping station, which has
a tank of diesel.

We have sufficient plumbing in the city, to run
anything you could want on natural gas. It's everywhere.

Sure, the natural gas system has a certain level of
redundancy in it. But think about this.

What is your earthquake plan ?

The phone system has to run after an earthquake.
If natural gas is leaking (trunk failure), it's
going to be turned off.

*******

Even a CO which is not on an active fault, has
an earthquake spec to meet. The equipment frames
are tied into members embedded in the concrete floor.
The frames are allowed to "sway". For a certain
amount of earthquake, there's a known amount of
deflection allowed for. And the interconnecting
cables are wrapped, with earthquake in mind.

A CO in SF likely has a different spec to meet,
than one of ours here. But even so, we don't rely
on natural gas.

And the phone company is filled with traditionalists.
They will continue to use lead acid batteries
instead of lithium, as the maintenance requirements
on lead acid are well known. There's less chance of a
fire.

In the event of an air conditioning failure in the
CO, the doors fly open, and the building is then
air cooled. The room temp rises to between 40C and
50C, and all the equipment has to take that. And that
defines the "temp spec". So if you're wondering why
the doors have a "latch to keep them open", there's
a reason.

While lots of aspects of the phone system "look cheap",
they do think about a few things. Who hasn't seen a
pedestal housing a punch-down block, lying out in the
weather with no protection, and nobody to care for it ?
That's a trademark of the phone company.

The only thing we don't do here, is lay cables on the
ground. Apparently, some areas allow this. Our wires
are always elevated. If it goes outside, it "flies
through the air", so it's less likely to snag on
something. Subdivisions have right-of-ways for such
routing. Not even the cable TV guys lay cable on
the ground here. It just isn't done.

And the main feed (multiple fiber optic cables) to my
neighborhood, is trenched below grade. That one isn't
aerial, as there's a considerable barrier in the way.
Even the hydro feed to the substation got buried. They
could have used towers, but buried it instead. Just
another one of those infrastructure rules at work...

Paul