[LINK] Four Corners NBN

[Richard Chirgwin]

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.

RC

> Marghanita