Im pretty confident if natural disaster were a major issue with ducted underground fiber there would be no shortage of documentation. Any hinderance to getting to your fiber will be present on gaining access to microwave (fire, water, structural failure). You can splice in heavy winds, with heavy snow/ice, in lightning, pretty much any condition that isnt actively on fire or under water. Getting a new tower in post earthquake is going to take much longer than an over the ground fiber splice. unless you ran through rock or concrete, underground sheering isnt probably very common, depending on the elevation change The lack of massive amounts of document tells me its a minimal risk.
On Mon, Feb 25, 2019 at 12:48 PM Robert Andrews <[email protected]> wrote: > I can put in personal experience on this from Loma Prieta quake. > Transportation gets pretty screwed up when the road has a 2.5 foot > vertical jumps. Dozers were needed to correct the problems and there > were enough breaks on the major through fare though the mountains that > it took a full week to doze access to people on that route. There were > probably around 30 locations that the road was just broken. If there > was fiber at the time, that would have probably been a LOT of breaks... > > On 02/25/2019 08:43 AM, Bill Prince wrote: > > > > Doesn't necessarily work after an earthquake. Roads, bridges, and so on > > are "unavailable" after an earthquake. You might not be able to get to a > > site, and/or the damage is so extensive, you need equipment that can't > > get to the site. > > > > We've had earthquakes with significant horizontal displacement, and the > > microwave links have remained functional. Sometimes we've seen minor SNR > > dropoff, but not in most cases. > > > > I would make the argument that each can be a backup for the other. If a > > link is really important, having multiple paths (microwave AND fiber) is > > probably a better argument. > > > > -- > > bp > > part15sbs{at}gmail{dot}com > > > > > > On Mon, Feb 25, 2019 at 8:31 AM <[email protected] > > <mailto:[email protected]>> wrote: > > > > I know I can throw a temp chunk of fiber on the ground and have > > things up > > and running in an hour or two. > > > > -----Original Message----- > > From: Robert > > Sent: Monday, February 25, 2019 9:23 AM > > To: [email protected] <mailto:[email protected]> > > Subject: Re: [AFMUG] Earthquake Fiber vs Microwave > > > > I would think that depends hugely upon the geography of the fiber > run. > > Fault zones in california can shift 9-12 feet in very tight shear in > a > > big one. Look at some of the pictures from the last quake in AK and > > you can see 15-18 foot displacements in x y and z. Would be tough to > > have confidence that your fiber would not get sheared in those > > conditions. Might be tough to have a microwave link survive that as > > well but if the tower isn't 100 feet tall and is anchored in bedrock > > might not have as much trouble. I don't know of any towers that went > > down in the Loma Prieta quake, the last large one I experienced. But > > there might be some people on this list that have more data on that. > > > > On 2/25/19 8:10 AM, [email protected] <mailto:[email protected]> wrote: > > > Trying to make the case that underground fiber will survive an > > earthquake > > > better than mountain top microwave for public safety uses. > > > > > > -----Original Message----- From: Seth Mattinen > > > Sent: Monday, February 25, 2019 9:07 AM > > > To: [email protected] <mailto:[email protected]> > > > Subject: Re: [AFMUG] Earthquake Fiber vs Microwave > > > > > > On 2/25/19 7:07 AM, [email protected] <mailto:[email protected]> > wrote: > > >> Anyone have some stories, perhaps from Alaska on earthquake > > survivability > > >> of fiber and microwave? > > >> I have to go to a meeting with some lawmakers later in the week > > to make > > >> the case that fiber has some slack, fiber can be fixed quickly. > > Towers > > >> can tilt or tumble. Antennas can get misaligned. And sometimes > > it is > > >> impossible to get to a snowy peak for a weak during a storm. > > >> Fiber is scalable. Microwave can be jammed and intercepted. > > Etc etc. > > >> Trying to be truthful and not gaslight anyone. > > > > > > > > > Just make sure your fiber doesn't run in conduit attached to any > > Cypress > > > Street Viaduct like structures. > > > > > > > -- > > AF mailing list > > [email protected] <mailto:[email protected]> > > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > > > > > -- > > AF mailing list > > [email protected] <mailto:[email protected]> > > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > > > > > > > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
-- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com
