I was just wondering as we do seem to be rushing headlong into the fibre to
home thing now, and I have this awful feeling that optical connectors and/or
the fibres themselves might be compromised by heat, cold or some other
environmental process and in a few years time we will be having to replace
them.
Brian

--

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Well as fibre optics are hardly new I’m gonna guess that people who know
about such stuff will have done some science to determine this rather than
asking a bloke in the pub if it’ll last.

Tim

Brian Gaff <brian1gaff@gmail.com> wrote:
> I was just wondering as we do seem to be rushing headlong into the fibre to
> home thing now, and I have this awful feeling that optical connectors and/or
> the fibres themselves might be compromised by heat, cold or some other
> environmental process and in a few years time we will be having to replace
> them.
> Brian
>

--
Please don't feed the trolls

Brian Gaff <brian1gaff@gmail.com> wrote:
> I was just wondering as we do seem to be rushing headlong into the fibre to
> home thing now, and I have this awful feeling that optical connectors and/or
> the fibres themselves might be compromised by heat, cold or some other
> environmental process and in a few years time we will be having to replace
> them.
> Brian
>
Casting around the Internet, it seems that there have been no significant
failures due to degradation in the 35 years that optical fibres have been
in the ground. As expected, the biggest cause of failure is mechanical
damage due to people, animals etc.

Brian Gaff <brian1gaff@gmail.com> wrote:

> I was just wondering as we do seem to be rushing headlong into the fibre to
> home thing now, and I have this awful feeling that optical connectors and/or
> the fibres themselves might be compromised by heat, cold or some other
> environmental process and in a few years time we will be having to replace
> them.

All glass is inherently unstable and will eventually crystalise, but the
time scale is geological.

A lot of research was done on chemical degredation of glass in the 1920s
and 30s by Philips, who needed various specialist types of glass for
light bulbs and valves. They found that some types degrade in damp
conditions, depending on the pH and mineral salts in the environment,
with a time-scale that is easily measurable in the laboratory; other
types take centuries. As with most chemical reactions, the speed
roughly doubles for every 10 degrees C.

Plastic fibres are another matter...

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Tweed <usenet.tweed@gmail.com> wrote:
> Brian Gaff <brian1gaff@gmail.com> wrote:
> > I was just wondering as we do seem to be rushing headlong into the fibre to
> > home thing now, and I have this awful feeling that optical connectors and/or
> > the fibres themselves might be compromised by heat, cold or some other
> > environmental process and in a few years time we will be having to replace
> > them.
> > Brian
> >
> Casting around the Internet, it seems that there have been no significant
> failures due to degradation in the 35 years that optical fibres have been
> in the ground. As expected, the biggest cause of failure is mechanical
> damage due to people, animals etc.

Trans-oceanic cables suffer from mechanical damage through earthquakes,
volcanoes, underwater landslides, etc, as well as dragging anchors and
fishing trawlers.

Those are not much to concern the average street connection.

Theo

Brian Gaff wrote:

> I was just wondering as we do seem to be rushing headlong into the fibre to
> home thing now, and I have this awful feeling that optical connectors and/or
> the fibres themselves might be compromised by heat, cold or some other
> environmental process and in a few years time we will be having to replace
> them.

I'm aware of installations that have been in place for 25 years, one
particular site has suffered rodent damage to some cores within a
multicore fibre between buildings.

On 07/12/2023 13:01, Liz Tuddenham wrote:
> As with most chemical reactions, the speed
> roughly doubles for every 10 degrees C.

The temperature change for the rate to double depend, inversely, on the
activation energy. 10K may be the typical ball park, but it depends on
the strength of the weakest bond.

However, it also seems that glass crystallisation is much more complex
than that, at least that is the impression I get by skimming
<https://core.ac.uk/reader/39209500>.

Andy Burns <usenet@andyburns.uk> wrote:

> Brian Gaff wrote:
>
> > I was just wondering as we do seem to be rushing headlong into the fibre to
> > home thing now, and I have this awful feeling that optical connectors and/or
> > the fibres themselves might be compromised by heat, cold or some other
> > environmental process and in a few years time we will be having to replace
> > them.
>
> I'm aware of installations that have been in place for 25 years, one
> particular site has suffered rodent damage to some cores within a
> multicore fibre between buildings.

Was it as quick and easy to effect a temporary repair as it would have
been with copper? The majority of day-to-day cable faults are
mechanical, so the downtime and the maintenance costs of fibre could
turn out to be greater than copper.

As Brian says, if there is also a long-term degradation problem, we
could be storing up trouble for the future.

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Liz Tuddenham wrote:

> Andy Burns wrote:
>
>> one particular site has suffered rodent damage to some cores within
>> a multicore fibre between buildings.
>
> Was it as quick and easy to effect a temporary repair as it would have
> been with copper?
No workable spare fibres were available, there was no attempt to repair,
there was space within the ducts to pull an extra fibre.

> The majority of day-to-day cable faults are
> mechanical, so the downtime and the maintenance costs of fibre could
> turn out to be greater than copper.

You could argue if it had been direct buried fibre without a duct there
wouldn't have been any rodent damage to begin with.

Andy Burns <usenet@andyburns.uk> wrote:

> Liz Tuddenham wrote:
>
> > Andy Burns wrote:
> >
> >> one particular site has suffered rodent damage to some cores within
> >> a multicore fibre between buildings.
> >
> > Was it as quick and easy to effect a temporary repair as it would have
> > been with copper?
> No workable spare fibres were available, there was no attempt to repair,
> there was space within the ducts to pull an extra fibre.
>
> > The majority of day-to-day cable faults are
> > mechanical, so the downtime and the maintenance costs of fibre could
> > turn out to be greater than copper.
>
> You could argue if it had been direct buried fibre without a duct there
> wouldn't have been any rodent damage to begin with.

It's also worrying that all the ducts nowadays seem to be made of
plastic. It is not unknown for the plasticiser of one type of plastic
to leach out and soften another plastic in contact with it over the
course of many years. If the cable sheaths or duct linings start to go
sticky or semi-liquid, it will be impossible to pull them out or pull
another one in.

Do the cable manufacturers talk to the duct manufacturers? Even if the
first generation of duct/cable materials has proved satisfactory, who is
checking that the next 'improvement' doesn't lay the foundations for
wholesale duct destruction in future?

--
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On 07/12/2023 11:20, Brian Gaff wrote:
> I was just wondering as we do seem to be rushing headlong into the fibre to
> home thing now, and I have this awful feeling that optical connectors and/or
> the fibres themselves might be compromised by heat, cold or some other
> environmental process and in a few years time we will be having to replace
> them.
> Brian
>

No. In fact they are AFAICT of an excellent design

Fibres span the world in undersea cables and have done for 40 years.
There isnt nuch about them that isnt well understood

--
Ideas are more powerful than guns. We would not let our enemies have
guns, why should we let them have ideas?

Josef Stalin

On 07/12/2023 14:25, Andy Burns wrote:
> Brian Gaff wrote:
>
>> I was just wondering as we do seem to be rushing headlong into the
>> fibre to
>> home thing now, and I have this awful feeling that optical connectors
>> and/or
>> the fibres themselves might be compromised by heat, cold or some other
>> environmental process and in a few years time we will be having to
>> replace
>> them.
>
> I'm aware of installations that have been in place for 25 years, one
> particular site has suffered rodent damage to some cores within a
> multicore fibre between buildings.

I worked on an undersea cable years ago. It was a favourite shark snack
apparently...

--
"If you don’t read the news paper, you are un-informed. If you read the
news paper, you are mis-informed."

Mark Twain

On 07/12/2023 14:51, Liz Tuddenham wrote:
> Andy Burns <usenet@andyburns.uk> wrote:
>
>> Brian Gaff wrote:
>>
>>> I was just wondering as we do seem to be rushing headlong into the fibre to
>>> home thing now, and I have this awful feeling that optical connectors and/or
>>> the fibres themselves might be compromised by heat, cold or some other
>>> environmental process and in a few years time we will be having to replace
>>> them.
>>
>> I'm aware of installations that have been in place for 25 years, one
>> particular site has suffered rodent damage to some cores within a
>> multicore fibre between buildings.
>
> Was it as quick and easy to effect a temporary repair as it would have
> been with copper? The majority of day-to-day cable faults are
> mechanical, so the downtime and the maintenance costs of fibre could
> turn out to be greater than copper.
>
In many cases it is in fact easier.

Unlike copper the kit needs to feature something with the ability to do
a precise clean right angled cut and exactly align the two fibre ends .
And, usually, a machine to measure the resultant quality

> As Brian says, if there is also a long-term degradation problem, we
> could be storing up trouble for the future.
>

We aren't, so stop being so wet,.

--
"If you don’t read the news paper, you are un-informed. If you read the
news paper, you are mis-informed."

Mark Twain

Hmm, but we are not talking about the big undersea ones any more, but the
ones that come to houses. Besides, back in the infancy of Fibre there were
reports of some crystalline formation in some fibre optic cables.
Brian

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"Tim+" <tim.downie@gmail.com> wrote in message
news:758835753.723641991.623990.tim.downie-gmail.com@news.individual.net...
> Well as fibre optics are hardly new I'm gonna guess that people who know
> about such stuff will have done some science to determine this rather than
> asking a bloke in the pub if it'll last.
>
> Tim
>
> Brian Gaff <brian1gaff@gmail.com> wrote:
>> I was just wondering as we do seem to be rushing headlong into the fibre
>> to
>> home thing now, and I have this awful feeling that optical connectors
>> and/or
>> the fibres themselves might be compromised by heat, cold or some other
>> environmental process and in a few years time we will be having to
>> replace
>> them.
>> Brian
>>
>
>
>
> --
> Please don't feed the trolls

Yes and apparently man with JCB digging holes in the wrong places of course.
So it may well be interconnects and boosters that will cause the issues
rather than the cables themselves.
Brian

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"Tweed" <usenet.tweed@gmail.com> wrote in message
news:uksbha$18g4h$1@dont-email.me...
> Brian Gaff <brian1gaff@gmail.com> wrote:
>> I was just wondering as we do seem to be rushing headlong into the fibre
>> to
>> home thing now, and I have this awful feeling that optical connectors
>> and/or
>> the fibres themselves might be compromised by heat, cold or some other
>> environmental process and in a few years time we will be having to
>> replace
>> them.
>> Brian
>>
> Casting around the Internet, it seems that there have been no significant
> failures due to degradation in the 35 years that optical fibres have been
> in the ground. As expected, the biggest cause of failure is mechanical
> damage due to people, animals etc.
>

Are plastic fibres used though, for comms, or just to make pretty Christmas
Trees?
Brian

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"Liz Tuddenham" <liz@poppyrecords.invalid.invalid> wrote in message
news:1qldd5b.9fbqn91fya9xeN%liz@poppyrecords.invalid.invalid...
> Brian Gaff <brian1gaff@gmail.com> wrote:
>
>> I was just wondering as we do seem to be rushing headlong into the fibre
>> to
>> home thing now, and I have this awful feeling that optical connectors
>> and/or
>> the fibres themselves might be compromised by heat, cold or some other
>> environmental process and in a few years time we will be having to
>> replace
>> them.
>
> All glass is inherently unstable and will eventually crystalise, but the
> time scale is geological.
>
> A lot of research was done on chemical degredation of glass in the 1920s
> and 30s by Philips, who needed various specialist types of glass for
> light bulbs and valves. They found that some types degrade in damp
> conditions, depending on the pH and mineral salts in the environment,
> with a time-scale that is easily measurable in the laboratory; other
> types take centuries. As with most chemical reactions, the speed
> roughly doubles for every 10 degrees C.
>
> Plastic fibres are another matter...
>
>
> --
> ~ Liz Tuddenham ~
> (Remove the ".invalid"s and add ".co.uk" to reply)
> www.poppyrecords.co.uk

Yes it worries me somewhat that Community Cable around here is in fact using
sewer pipes to run their cables in. If you are going to get a cable damaged
its going to be in a sewer as there are rats and fat burgs down there.
Brian

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"Andy Burns" <usenet@andyburns.uk> wrote in message
news:kte5quFp1voU1@mid.individual.net...
>
> Liz Tuddenham wrote:
>
>> Andy Burns wrote:
>>
>>> one particular site has suffered rodent damage to some cores within
>>> a multicore fibre between buildings.
>>
>> Was it as quick and easy to effect a temporary repair as it would have
>> been with copper?
> No workable spare fibres were available, there was no attempt to repair,
> there was space within the ducts to pull an extra fibre.
>
>> The majority of day-to-day cable faults are
>> mechanical, so the downtime and the maintenance costs of fibre could
>> turn out to be greater than copper.
>
> You could argue if it had been direct buried fibre without a duct there
> wouldn't have been any rodent damage to begin with.
>

Brian Gaff wrote:

> Are plastic fibres used though, for comms, or just to make pretty Christmas
> Trees?

no, just s/pdif audio and probably lamps

On 08/12/2023 10:15, Brian Gaff wrote:
> Are plastic fibres used though, for comms, or just to make pretty Christmas
> Trees?
> Brian
>
Not for long distance monomode.

I think.

--
"In our post-modern world, climate science is not powerful because it is
true: it is true because it is powerful."

Lucas Bergkamp

Which is faster, fibre optics and booster stations or ordinary copper and
booster stations. I'll agree that there is less electromagnetic effects with
fibre, and some clever scientists have found a way to use them to detect
earthquakes!

Brian

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"The Natural Philosopher" <tnp@invalid.invalid> wrote in message
news:ukssmj$1b23b$3@dont-email.me...
> On 07/12/2023 11:20, Brian Gaff wrote:
>> I was just wondering as we do seem to be rushing headlong into the fibre
>> to
>> home thing now, and I have this awful feeling that optical connectors
>> and/or
>> the fibres themselves might be compromised by heat, cold or some other
>> environmental process and in a few years time we will be having to
>> replace
>> them.
>> Brian
>>
>
> No. In fact they are AFAICT of an excellent design
>
> Fibres span the world in undersea cables and have done for 40 years. There
> isnt nuch about them that isnt well understood
>
> --
> Ideas are more powerful than guns. We would not let our enemies have guns,
> why should we let them have ideas?
>
> Josef Stalin
>

On 09/12/2023 12:57, Brian Gaff wrote:
> Which is faster, fibre optics and booster stations or ordinary copper and
> booster stations. I'll agree that there is less electromagnetic effects with
> fibre, and some clever scientists have found a way to use them to detect
> earthquakes!
There aren't any booster stations on fibre optic systems on the last
"mile", which is the only place where long copper wires are used. The
backbone is already fibre.
The velocity factor for optical fibre is around that for coaxial cable,
and lower than that for twisted pair. Assuming the "last mile" is 2km,
that's about 1µs one way advantage for twisted pair over fibre.
Of course, when people talk about speed, they are often talking about
data rate, which is orders of magnitude higher for fibre.
There is also the fact that xDSL has a low baud rate, so the
serialisation delays for symbol formation (125µs) are much higher than
any light travel time advantage.
Velocity factor source: <https://en.wikipedia.org/wiki/Velocity_factor>
Baud rate source: <https://www.draytek.co.uk/information/blog/dsl-deep-dive>

Back in my youth, the only use of primitive fibre optics was in Corgi toys
where the lights lit up courtesy of a bulb and some fibres feeding to the
lights. They never looked that realistic, since they were so directional.
Brian

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"David Woolley" <david@ex.djwhome.demon.invalid> wrote in message
news:ul1t56$27ua2$1@dont-email.me...
> On 09/12/2023 12:57, Brian Gaff wrote:
>> Which is faster, fibre optics and booster stations or ordinary copper
>> and
>> booster stations. I'll agree that there is less electromagnetic effects
>> with
>> fibre, and some clever scientists have found a way to use them to detect
>> earthquakes!
>
> There aren't any booster stations on fibre optic systems on the last
> "mile", which is the only place where long copper wires are used. The
> backbone is already fibre.
>
> The velocity factor for optical fibre is around that for coaxial cable,
> and lower than that for twisted pair. Assuming the "last mile" is 2km,
> that's about 1�s one way advantage for twisted pair over fibre.
>
> Of course, when people talk about speed, they are often talking about data
> rate, which is orders of magnitude higher for fibre.
>
> There is also the fact that xDSL has a low baud rate, so the serialisation
> delays for symbol formation (125�s) are much higher than any light travel
> time advantage.
>
> Velocity factor source: <https://en.wikipedia.org/wiki/Velocity_factor>
>
> Baud rate source:
> <https://www.draytek.co.uk/information/blog/dsl-deep-dive>
>

On Sun 10/12/2023 13:44, Brian Gaff wrote:
> Back in my youth, the only use of primitive fibre optics was in Corgi toys
> where the lights lit up courtesy of a bulb and some fibres feeding to the
> lights. They never looked that realistic, since they were so directional.
> Brian
>

Sorry Brian, not fibres but a new fangled toy called light pipes.
Basically a piece of plastic possibly with bends in it where the outside
of the 'bend' was actually a highly polished and very flat piece of
plastic face that to the inside of the light pipe acted like a mirror.
Such devices were used in radios especially car radios and many uses of
that type. It meant that one bulb could be used to 'light' several
points - note this was at a time that so-called pea-bulbs were the norm.
Get into the late 70's or early 80's and LEDs became very widely
available and very very cheap although even then they were wire-ended
devices. When SMD LEDs became the norm was when we ended up with places
such as car dashboards that looked like Blackpool Illuminations!

On 10/12/2023 16:38, Woody wrote:
> Sorry Brian, not fibres but a new fangled toy called light pipes.
> Basically a piece of plastic possibly with bends in it where the outside
> of the 'bend' was actually a highly polished and very flat piece of
> plastic face that to the inside of the light pipe acted like a mirror.

Light pipes and multimode fibres work on the same principle. Multimode
fibres are basically just narrow light pipes.

> When SMD LEDs became the norm was when we ended up with places such as car dashboards that looked like Blackpool Illuminations!

SMD LEDs are often used to drive, short, light pipes, in modern designs.

On 10/12/2023 17:58, David Woolley wrote:
> On 10/12/2023 16:38, Woody wrote:
>> Sorry Brian, not fibres but a new fangled toy called light pipes.
>> Basically a piece of plastic possibly with bends in it where the
>> outside of the 'bend' was actually a highly polished and very flat
>> piece of plastic face that to the inside of the light pipe acted like
>> a mirror.
>
> Light pipes and multimode fibres work on the same principle.  Multimode
> fibres are basically just narrow light pipes.
>
+1

>> When SMD LEDs became the norm was when we ended up with places such as
>> car dashboards that looked like Blackpool Illuminations!
>
> SMD LEDs are often used to drive, short, light pipes, in modern designs.
>
Yup.

>

--
"It is an established fact to 97% confidence limits that left wing
conspirators see right wing conspiracies everywhere"