[LINK] Four Corners NBN

[Marghanita da Cruz]

Richard Chirgwin wrote:
> On 16/04/11 6:06 PM, Marghanita da Cruz wrote:
>> David Boxall wrote:
>>> On 13/04/2011 10:03 AM, Marghanita da Cruz wrote:
>>>> ... a few years ago, the need for underground cabling, in
>>>> some parts of Sydney, made the media a lot, ...
>>> Knowing the reliability and safety benefits (not to mention long-term
>>> cost efficiencies) of underground infrastructure and having experienced
>>> some of the hazards of overhead electricity cables myself, it surprises
>>> me that distributing power through naked overhead wires is still
>>> accepted, particularly in urban areas. Come to think of it, I'm
>>> surprised that it's legal. Perhaps the familiarity of the hazards blinds us.
>>>
>> I think you will find that there are strong OH&S standards
>> as well as safety cutouts - these are certainly requirements
>> on the domestic front.
>>
>> Visible overhead cables are much safer than underground
>> cables. The telstra copper cable in the ground from the
>> street to my premises is in a bit of plastic pipe!
> That's not unusual. PVC conduit can last a very long time - this 
> document gives the lifetime of a PVC water pipe as 100 years:
> 
> www.teppfa.org/pdf/CivilsLifetimeofPVCpipes1.pdf
> 
> Not only is the final cable going to be in a PVC conduit, I would 
> imagine that 100mm or bigger PVC conduits are used for larger cable 
> bundles. Given that fibres are much less subject to environmental 
> effects than copper, the PVC pipe is more than fit for purpose.
> 

FWIW the copper is in a 25mm black flexible tubing, yes it
can last quite a long time, I expect the one in my garden
has been there for a fair few years. Though a shovel could
quite easily cut through it.

These cables are nowhere as deep as the electricity conduits
they are laying in the street.

Something else, I reported to Telstra about a year or so
ago, was a split metal conduit, in the verge, which had been
pushed up and broken by a tree root, exposing the cable inside.

Yes, Foxtel wanted to lay cable, to the premises, but they
were going to take a different path to the copper.

Then there are the water and gas pipes...doesn't leave a lot 
of room in a garden for plants.

Marghanita
-- 
Marghanita da Cruz
http://ramin.com.au
Tel: 0414-869202