[LINK] Ever-lasting copper

[David Boxall]

Thanks Richard.

On 8/01/2014 10:33 PM, Richard wrote:
> Well, you could stop bothering to try to teach sense to idiots.
>
They're better organised than that. When I counter one line, they just 
come back with another.

They won't learn; learning wouldn't further their cause. My concern is 
with the silent reader, who risks being misled.

> But I have a real, current and close experience. Lightning. A lightning
> strike in Wentworth Falls - one lightning strike - destroyed the
> insulation in a cable run. I spent Monday afternoon with a Telstra tech,
> starting at the termination point at my business and working back to
> find where the damage ended.
>
> The result of this one lightning strike is that a 100-metre cable run
> has been rendered useless. There is one good pair left, which happened
> to belong to my neighbour. I just happened to be the first to complain -
> and the result will be that Telstra has to trench new cable for the
> whole run.
>
You're lucky you weren't on the 'phone at the time. I've already linked 
to <http://www.snopes.com/horrors/techno/phone.asp>. That successfully 
neutralised the backup battery objection. There used to be a warning in 
the paper 'phone book; is that still so?

> The copper *network* could be maintained forever, but only with regular
> maintenance and replacement. Some of that is that to keep copper in
> pristine conditions, you have to provide it with an ideal environment.
> That means doing things like giving it a pressurised environment (which
> costs money).
>
I've heard repeatedly that the service life of copper cable is 30 to 50 
years, depending on environment. Why is that? What happens to the cable? 
My neighbour's report is interesting, but I need a more credible source.

In my area, line noise and reliability degraded to the point that 
Telstra had to replace the cable. So what caused the degradation? If it 
was just joint failure, why replace the whole cable?

> Optical fibre, on the other hand, is nowhere near as fussy. There is a
> Corning study which I've linked to before here, in which a fibre cable
> was retrieved after 20 years of flood-heat cycles, in which the glass
> showed no measurable deterioration from when it was new.
>
If you could repost that link, I'd be grateful.

> You might also think about this: Australia has zero copper-based
> submarine cables still in service. On the other hand, I am not aware
> that Australia has *ever* decommissioned a submarine fibre.
>
> RC
>
-- 
David Boxall                         | ignorance more frequently
                                     | begets confidence than does
http://david.boxall.id.au            | knowledge
                                     | --Charles Darwin (introduction
                                     |  to 'The Descent of Man' 1871)