[mythtv-users] Underground vs. Overhead Utilities

[Brian Wood]

On Tuesday 27 January 2009 18:19:00 you wrote:
> On Tue, 2009-01-27 at 16:31 -0700, Brian Wood wrote:
> > > Water and sewage have to be underground to start, so you have to dig.
> > > It is not that much more expensive to add pipe for natural gas,
> > > electrical, cable and telephone. Then you only have watch out for
> > > hungry backhoes... and worry about broken water-mains.
> >
> > I have never heard of any place where water, gas and electric were in the
> > same tranch. Can you imagine what would happen if a backhoe did hit that
> > collection of utilities? i wouldn't want to be anywhere near it. As was
> > pointed out, the cable itself is more expensive for underground use. In
> > most locations high voltage (at least primary, if not secondary) has to
> > be isolated from low-voltage stuff like telephone and cable TV by a
> > buffer of sand or other method.
>
> Brian, this has actually been done for a long time in cold places,
> and geologically active places like Japan. Where I've seen it, a
> trench is dug for a concrete conduit then the utilities are placed
> inside. The conduit is large enough to allow robotic access with
> concrete roof panels for opening things up, or are large enough
> to allow a small person comfortable access. The municipality owns
> the conduit itself and charges a small fee to the utilities using
> it. This allows repairs without as much expensive digging, and
> backhoe operators just don't attack the electric, gas and water
> conduit with the same vigor they employ against fiber and other
> wimpy utilities. ;]

I guess knowing you could be killed would cause you to be more careful.

I once saw a backhoe that had hit a 250KV primary, blew the tires right off 
it. At least the operator was smart enough to jump off, not contact the 
ground and the machine at the same time.

Sounds like NYC a little bit, where ConEd owns the ducts and you lease them 
from them if you want to blow fibre in.

A lot of T/W cable TV is in fact running in subway tunnels.

-- 
beww
beww at beww.org