Have you checked available rights of way lately? They haven't changed much
for quite a while. Telecom has not really any ability to build dedicated
bridges for telcom fibre. It uses existing facilities wherever possible.
Following the paths of least cost/resistance, this pretty much determines
that rivers and bridges become choke-points. The only real alternatives are
microwave towers (a cost/benefit argument I won't touch, even with your
ten-foot pole).
WRT the other comment about that MCI conduit on the tunnel wall, I have
reports that temperatures are exceeding 1000F, near the fire. I submit that
no amount of armor-clading is going to shield that cable, from those temps.
The only cable that might survive is whatever may be buried under the
road-bed.
There's a paper out from a civil engineering grad student at either
Rutgers or Princeton that examines, among other things, available rights
of way and the who, where and how of their use. It's an extremely
interesting read.
One interesting point made within is that in over 90% of urban and
suburban areas in the U.S. which are traversed by rivers, bridges are
spaced an average of less than 6 miles apart. Of those, over 75% fall
within either state or federal responsibility, and include rights of way
for cabling, water, etc.
I'll dig up the title/author on Monday.
-brian
:Have you checked available rights of way lately? They haven't changed much
:for quite a while. Telecom has not really any ability to build dedicated
:bridges for telcom fibre. It uses existing facilities wherever possible.
:Following the paths of least cost/resistance, this pretty much determines
:that rivers and bridges become choke-points. The only real alternatives are
:microwave towers (a cost/benefit argument I won't touch, even with your
:ten-foot pole).
I would think that if fiber can be run across oceans without using tunnels
or bridges, that it could be run across some rivers much the same way, no?
James Smallacombe PlantageNet, Inc. CEO and Janitor
up@3.am http://3.am
I would think that if fiber can be run across oceans without using tunnels
or bridges, that it could be run across some rivers much the same way, no?
the biggest exposure to cut for wet fiber is shallow water. anchors,
idiots, ...
Yes, I can see that; but I imagine you could handle this much the way
fiber is handled near the shoreline. Bury it a few feet under the mud or
sand.
James Smallacombe PlantageNet, Inc. CEO and Janitor
up@3.am http://3.am
:> > I would think that if fiber can be run across oceans without using tunnels
:> > or bridges, that it could be run across some rivers much the same way, no?
:>
:> the biggest exposure to cut for wet fiber is shallow water. anchors,
:> idiots, ...
:
:Yes, I can see that; but I imagine you could handle this much the way
:fiber is handled near the shoreline. Bury it a few feet under the mud or
:sand.
One complication of traversing rivers underwater is that, depending on the
locale, many rivers have a dredged shipping channel which can be _much_
deeper than the rest of the riverbed, and is often relatively very
narrow. I'm not sure this is an issue which couldn't be overcome based
solely on financial incentive, however.
Keep in mind, too, that every crossing isn't going to be a nice, deep river... I can think of hundreds of cases (and so can you) where the crossing is over a shallow creek or fairly deep ravine (no water at all!) - yet difficult at best to trench it in... so cables, pipelines, etc, ride the bridge...
Then your friendly local tropical storm comes along, drops plenty of water, and the bridge washes out. Now what? Reroute everything, of course. Or a tank truck catches fire and destroys the bridge (as happened in Atlanta not long ago - sure, it was I-285, and I don't think any cables rode that bridge),
Obviously when routing cables, you have to deal with the cost/benefit ratio. What are the chances of any single point suffering catastrophic failure? How much will it cost to trench it in instead of riding a bridge/tunnel? You make a decision, then you deal with the consequences if you're wrong.
More than worry about exactly what method is used for routing cables, I agree with building redundancy. Because no matter how you armor/protect your cables, something CAN occur that'll break through that protection... but if you have a backup in place, routed another way, with automatic failover, you barely notice. More importantly, your customers DON'T notice.
currents, frequent dredgeing and construction make riverbeds kind of
unattractive.
joelja
Hey, genius, I got a question for you. How were planning to get to that
[river|stream|lake|etc]shore? The rights of way lead to existing bridges
and tunnels. Buying a contiguous right of way in America is exorbitantly
expensive, if it's even possible, which I highly doubt. If you're already
at a bridge, tunnel, whatever, (because hey, that's where the existing
right of way you're using takes you) why wouldn't you use it?
Your .sig lists you as CEO, yet you seem to lack the basic knowledge that
corporate officers are beholden to their shareholders, doing what's cheap
right now vs. what makes sense over time. The forces driving major
telcos are many, and long range planning at the expense of today's stock
price is not one of them.
Others have brought up the issues with cabling across an active river
trade route, so I'll not rehash them.
Jamie Bowden
> > :Have you checked available rights of way lately? They haven't changed much
> > :for quite a while. Telecom has not really any ability to build dedicated
> > :bridges for telcom fibre. It uses existing facilities wherever possible.
> > :Following the paths of least cost/resistance, this pretty much determines
> > :that rivers and bridges become choke-points. The only real alternatives are
> > :microwave towers (a cost/benefit argument I won't touch, even with your
> > :ten-foot pole).
> I would think that if fiber can be run across oceans without using tunnels
> or bridges, that it could be run across some rivers much the same way, no?
Hey, genius, I got a question for you. How were planning to get to that
[river|stream|lake|etc]shore? The rights of way lead to existing bridges
and tunnels. Buying a contiguous right of way in America is exorbitantly
expensive, if it's even possible, which I highly doubt. If you're already
at a bridge, tunnel, whatever, (because hey, that's where the existing
right of way you're using takes you) why wouldn't you use it?
I didn't think we were discussing right-of-way issues, so much as diverse
redundancy issues at "choke points" (see above). If everybody's fiber
goes through the same tunnel, and the tunnel has a bad fire, that can
lead to nasty outages...wait, it just *did* that, didn't it (not that
this situation was even a river, but I digress)? Anyway, it would seem
that unless you bury it fairly deeply under the riverbed, it ain't such a
great idea. There goes my Mensa application...
Your .sig lists you as CEO, yet you seem to lack the basic knowledge that
corporate officers are beholden to their shareholders, doing what's cheap
right now vs. what makes sense over time. The forces driving major
telcos are many, and long range planning at the expense of today's stock
price is not one of them.
It also lists me as Janitor, are you going to now attack my dusting
technique? I'll have you know that I can empty a trash can with the best
of them!
It might also clue you in as to how many "shareholders" I'm beholden to.
James Smallacombe PlantageNet, Inc. CEO and Janitor
up@3.am http://3.am