What it this: Outside Telco "Cable"

Hi:
Seems that everywhere I look in our semi-rural county I see these aerael cables. They are suspected from a steel cable but the interesting thing is
that they seem to have been sent to the linemen as a pre-fab, fixed length assembly.
Sections are joined by plugging into one end of a cylinder that's about 1' by 5" diameter. Today the end of each section there is a place where slack is taken up by turning the cable around a "thimble" which limits the turning radius to about 4". There are two such "turns" to take up slack and between the turns there are 3 cable sections.
Don't have pictures as this is something I see where I drive but I don't want to stop and don't usually bring a camera with with me.
It's been 30 years since I have been in the "telephone business" so I curious about whats going on.
thanks
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On Thu, 19 Aug 2010 08:30:49 -0400, "John Gilmer"

In all likelihood you are seeing fiber optic cable that is used either by the telephone company or the cable TV company. Electric power utilities also use it. It typically contains lots of individual fibers (144 used to be one number, but it varies depending on the route requirements). As glass fibers have a minimum bend radius to prevent damage and since the splices cannot be made up on the pole, the cable has enough slack at each end to bring it down to a truck for splicing. The "thimbles" are used when the slack is placed back on the line to prevent violating the minimum bend radius. The length of the cable run is variable, but is also dependent on the cable reel and the effort required to pull it. As I recall, 2500 feet was a "standard" reel, but you can get any length you want.
Hope this helps.
ET
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It does! Thanks.
I talked with a telco guy some months ago (don't remember the context) but he told me there wasn't any fibre associate with the local telephone company in the country. (AT&T run an interstate fibre backbone some 10 years ago.)
I guess that means it belongs to the cable company.
What's it's called? (Fibre is just a little to broad for a google search.)
We miss getting cable by about 1 road mile. So close but so far! I guess we will be stuck with dial up for another few years.
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I had been wondering about those "thimbles" for months! There are many of them in Redwood City, California, particularly along Redwood Avenue, wich I travel frequently. The cables seem to terminate in the cylinders as you describe. I did not know that the cables are plugged into the cylinders; I assumed that the cylinders were ordinary splices. Thanks for solving the mystery!
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On Thu, 19 Aug 2010 23:25:51 -0400, "John Gilmer"

Local telephone companies use fiber between their central offices and also to connect remote switching/concentration modules to the central office. Verizon offers Fios service, which is fiber based, directly to the customer in many locations and larger businesses may have fiber connections to the telco. All in all, there is a lot of fiber being used by the local telephone companies.
Cable companies also have placed lots of fiber, particularly since they started providing internet access and offering HD channels. Power companies often use fiber for instrumentation/control of their facilities due to its immunity to electrical noise, which can be severe in a substation if a fault occurs. A while back the local power company was talking about (actually they did a field trial) providing internet access via fiber. They later dropped the residential part of the service as they would end up putting lots of fiber and competing with the telcos and cable companies. Kind of made the business less profitable than selling electricity...
The cost of installing fiber is comparable to installing copper, the information capacity is much greater, and the maintenance cost is lower, so there is lots of incentive to use it.
AFAIK, the cable is known as outside plant fiber optic cable.
Hope this helps.
ET
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