6 ms·

I strongly doubt there are any non-fiber submarine cables. Fiber's main strength is range; trying to run signals over electrical conductors over hundred-km-plus

I strongly doubt there are any non-fiber submarine cables. Fiber's main strength is range; trying to run signals over electrical conductors over hundred-km-plus distances is not cost-effective and hasn't been for decades. (It's been done historically, but with very heavy cables, very high endpoint power levels, lots of repeaters, and really poor throughput.)

hnarn 5y ago
> I strongly doubt there are any non-fiber submarine cables. I strongly doubt electrical cables are fiber cables for example :-) On a more serious note, I was thinking that there are perhaps copper cables used for telephone communications that are still used simply because they haven't yet failed, but I assume fiber has perhaps been the standard for backbones long before it became something people have in their homes.
- jhgb 5y ago
  Wouldn't it make sense for some electrical cables to have some fiber in them? When you're already laying them, you could get two services for the price of one.
  - hnarn 5y ago
    I suppose it would, I guess I'm just wondering for how long fiber cables have been the standard, and if there are any operational cables from the time before that. I'm pretty sure there are plenty of cables dedicated for one purpose (e.g. electricity only) that do not contain fiber simply because there wasn't a need or requirement when it was planned. edit: Here's an example: > The world record from 1994, for the longest HVDC cable with the highest capacity, was equalled in 2000 with the successful completion of the Swedish-Polish HVDC transmission link between Sweden and Poland: > 1. Stretching over 250 km, it is one of the two longest submarine HVDC cables ever laid. > 2. At 600 MW, the cable is one of the most powerful HVDC cables in commercial operation. > 3. At 450 kV DC, this cable together with the cable between Sweden and Germany, has the highest voltage rating of all existing submarine HVDC cables. This cable doesn't seem to have any other purpose than transferring electricity, and it was installed "only" 21 years ago.
  - dtech 5y ago
    I highly doubt it's cost-effective. These things are complicated and have specialized equipment. The endpoints also very different for data and electricity.
  - cranekam 5y ago
    I'm certainly no expert here but I'm guessing it doesn't make sense for two reasons: 1) Modern communications fibers are complicated (https://en.wikipedia.org/wiki/Submarine_communications_cable https://en.wikipedia.org/wiki/Submarine_communications_cable [1]) and presumably expensive so speculatively adding them to power cables would likely be a pricey endeavor. 2) AFAIK most submarine cables are systems — e.g. a ring the connects various places so that there are two paths between points — so trying to plan one to that co-opts existing bits of fiber piggy-backed on power probably wouldn't be easy. Also you'd have the issue of dealing with different generations of fiber, standards, etc. [1] On reading this it turns out that modern fibers actually carry power as well so that repeaters en route can be powered.
  - tbihl 5y ago
    In almost all conceivable contexts, no. If you've ever done any work with electrical code, you are familiar with the spacing requirements between electrical conduit and data wires to prevent magnetic interference: at least a foot apart, and perpendicular crossings if crossings are necessary. The voltage on underwater electrical cables are quite high, as is the bandwidth on underwater data cables, so you definitely can't have them mixing if you want anything near optimum results on data transfer.
    - fsckboy 5y ago
      he was asking about fiber which is not subject to electro-magnetic interference
      - midasuni 5y ago
        Even setting that aside Undersea power is DC
  - cycomanic 5y ago
    Optical fibres are also pretty good sensors so it's not unlikely that some fibres are added just for sensing purposes (they are eput into lots of bridges and other things for example). That said it highly depends on the length of your electrical cables if putting in fibre for communications makes sense. Typically (grossly simplified) you need optical amplifiers when you go significantly over transmission distances of 100km so they need power supplies, take up quite a bit of space etc..
  - walrus01 5y ago
    Already a thing, one of the high voltage power cables to Tasmania also has singlemode fiber in it. Not uncommon.
    - shoo 5y ago
      Shown on the map as "basslink". you can find it on the southern side of australia, it's the easternmost tiny little line crossing INDIGO central. 500 MW electricity interconnector + bonus 12 core fire cable https://en.wikipedia.org/wiki/Basslink#Basslink_Telecoms https://en.wikipedia.org/wiki/Basslink#Basslink_Telecoms
  - alerighi 5y ago
    They probably already had some inside but not for general use, but to exchange data between the two ends of the cable. Modern power grid is smart, and it has data connection along side power, they do that also on overhead power lines (the upper cable beside the three phases serves as a protectoin from lightning strikes but also has a fiber inside). In practice the power network also has a completely isolated LAN (for obvious security reasons) to manage the whole infrastructure. At least in my country it's done like that.
waynecochran 5y ago
Doesn't a lot of these cables pre-date fiber? They had these in WWII. I remember the Gilligan's Island episode where the cable washes up in the lagoon and the professor was able to connect up a phone so they call around the world -- of course Gilligan screws it all up at the end.
- gok 5y ago
  Until the 1950s, transatlantic communication was done with radio. Then it was copper until the 80s
  - jkepler 5y ago
    But weren't the British Empire's undersea telegraph lines all copper? They lay the first transatlantic cable in 1858, connecting Ireland and Newfoundland. By 1911 their worldwide undersea network was completed, with so much redundancy that 49 cuts would have been necessary to isolate the United Kingdom from its empire. https://en.m.wikipedia.org/wiki/All_Red_Line https://en.m.wikipedia.org/wiki/All_Red_Line
- azernik 5y ago
  None of that stuff is still in service. (At least not telecom.) They require periodic, expensive maintenance, and fiber outclasses copper for long-distance signatures to a much greater degree than for the last-mile ground traffic for which copper is still used.
  - seniorivn 5y ago
    fiber quickly replaces copper ethernet in telecom in competitive markets (where 1gbps is an actual offer)
walrus01 5y ago
> I strongly doubt there are any non-fiber submarine cables. not for telecom, not anymore, but a number of submarine cable laying ships are equipped specifically for laying high voltage power cables to offshore wind farms. And for things like high voltage cables linking medium sized islands to a nearby mainland (eg: Vancouver Island, BC to the continent). After submarine telecom, the biggest uses for such vessels are offshore power and the oil/gas industry.
- isthisnametaken 5y ago
  Not just medium-sized islands. The UK has several interconnectors to other European countries for importing and exporting power https://www.nationalgrid.com/our-businesses/national-grid-ventures/interconnectors-connecting-cleaner-future https://www.nationalgrid.com/our-businesses/national-grid-ve...
  - spzb 5y ago
    One less than usual at the moment though https://www.bbc.co.uk/news/uk-england-kent-58570893 https://www.bbc.co.uk/news/uk-england-kent-58570893
retrac 5y ago
Some coaxial lines were laid until the 1980s. Seems likely that at least one small island somewhere has a copper submarine cable supplying their data/phone needs still. But it's decidedly obsolete, yes.
sathackr 5y ago
Current fiber-containing submarine cables also have electrical lines to power inline amplifiers. Even fiber signals can't travel those kinds of distances without repeaters.

hnarn 5y ago

> I strongly doubt there are any non-fiber submarine cables. I strongly doubt electrical cables are fiber cables for example :-) On a more serious note, I was thinking that there are perhaps copper cables used for telephone communications that are still used simply because they haven't yet failed, but I assume fiber has perhaps been the standard for backbones long before it became something people have in their homes.

jhgb 5y ago
Wouldn't it make sense for some electrical cables to have some fiber in them? When you're already laying them, you could get two services for the price of one.
- hnarn 5y ago
  I suppose it would, I guess I'm just wondering for how long fiber cables have been the standard, and if there are any operational cables from the time before that. I'm pretty sure there are plenty of cables dedicated for one purpose (e.g. electricity only) that do not contain fiber simply because there wasn't a need or requirement when it was planned. edit: Here's an example: > The world record from 1994, for the longest HVDC cable with the highest capacity, was equalled in 2000 with the successful completion of the Swedish-Polish HVDC transmission link between Sweden and Poland: > 1. Stretching over 250 km, it is one of the two longest submarine HVDC cables ever laid. > 2. At 600 MW, the cable is one of the most powerful HVDC cables in commercial operation. > 3. At 450 kV DC, this cable together with the cable between Sweden and Germany, has the highest voltage rating of all existing submarine HVDC cables. This cable doesn't seem to have any other purpose than transferring electricity, and it was installed "only" 21 years ago.
- dtech 5y ago
  I highly doubt it's cost-effective. These things are complicated and have specialized equipment. The endpoints also very different for data and electricity.
- cranekam 5y ago
  I'm certainly no expert here but I'm guessing it doesn't make sense for two reasons: 1) Modern communications fibers are complicated (https://en.wikipedia.org/wiki/Submarine_communications_cable https://en.wikipedia.org/wiki/Submarine_communications_cable [1]) and presumably expensive so speculatively adding them to power cables would likely be a pricey endeavor. 2) AFAIK most submarine cables are systems — e.g. a ring the connects various places so that there are two paths between points — so trying to plan one to that co-opts existing bits of fiber piggy-backed on power probably wouldn't be easy. Also you'd have the issue of dealing with different generations of fiber, standards, etc. [1] On reading this it turns out that modern fibers actually carry power as well so that repeaters en route can be powered.
- tbihl 5y ago
  In almost all conceivable contexts, no. If you've ever done any work with electrical code, you are familiar with the spacing requirements between electrical conduit and data wires to prevent magnetic interference: at least a foot apart, and perpendicular crossings if crossings are necessary. The voltage on underwater electrical cables are quite high, as is the bandwidth on underwater data cables, so you definitely can't have them mixing if you want anything near optimum results on data transfer.
  - fsckboy 5y ago
    he was asking about fiber which is not subject to electro-magnetic interference
    - midasuni 5y ago
      Even setting that aside Undersea power is DC
- cycomanic 5y ago
  Optical fibres are also pretty good sensors so it's not unlikely that some fibres are added just for sensing purposes (they are eput into lots of bridges and other things for example). That said it highly depends on the length of your electrical cables if putting in fibre for communications makes sense. Typically (grossly simplified) you need optical amplifiers when you go significantly over transmission distances of 100km so they need power supplies, take up quite a bit of space etc..
- walrus01 5y ago
  Already a thing, one of the high voltage power cables to Tasmania also has singlemode fiber in it. Not uncommon.
  - shoo 5y ago
    Shown on the map as "basslink". you can find it on the southern side of australia, it's the easternmost tiny little line crossing INDIGO central. 500 MW electricity interconnector + bonus 12 core fire cable https://en.wikipedia.org/wiki/Basslink#Basslink_Telecoms https://en.wikipedia.org/wiki/Basslink#Basslink_Telecoms
- alerighi 5y ago
  They probably already had some inside but not for general use, but to exchange data between the two ends of the cable. Modern power grid is smart, and it has data connection along side power, they do that also on overhead power lines (the upper cable beside the three phases serves as a protectoin from lightning strikes but also has a fiber inside). In practice the power network also has a completely isolated LAN (for obvious security reasons) to manage the whole infrastructure. At least in my country it's done like that.

waynecochran 5y ago

Doesn't a lot of these cables pre-date fiber? They had these in WWII. I remember the Gilligan's Island episode where the cable washes up in the lagoon and the professor was able to connect up a phone so they call around the world -- of course Gilligan screws it all up at the end.

gok 5y ago
Until the 1950s, transatlantic communication was done with radio. Then it was copper until the 80s
- jkepler 5y ago
  But weren't the British Empire's undersea telegraph lines all copper? They lay the first transatlantic cable in 1858, connecting Ireland and Newfoundland. By 1911 their worldwide undersea network was completed, with so much redundancy that 49 cuts would have been necessary to isolate the United Kingdom from its empire. https://en.m.wikipedia.org/wiki/All_Red_Line https://en.m.wikipedia.org/wiki/All_Red_Line
azernik 5y ago
None of that stuff is still in service. (At least not telecom.) They require periodic, expensive maintenance, and fiber outclasses copper for long-distance signatures to a much greater degree than for the last-mile ground traffic for which copper is still used.
- seniorivn 5y ago
  fiber quickly replaces copper ethernet in telecom in competitive markets (where 1gbps is an actual offer)

walrus01 5y ago

> I strongly doubt there are any non-fiber submarine cables. not for telecom, not anymore, but a number of submarine cable laying ships are equipped specifically for laying high voltage power cables to offshore wind farms. And for things like high voltage cables linking medium sized islands to a nearby mainland (eg: Vancouver Island, BC to the continent). After submarine telecom, the biggest uses for such vessels are offshore power and the oil/gas industry.

isthisnametaken 5y ago
Not just medium-sized islands. The UK has several interconnectors to other European countries for importing and exporting power https://www.nationalgrid.com/our-businesses/national-grid-ventures/interconnectors-connecting-cleaner-future https://www.nationalgrid.com/our-businesses/national-grid-ve...
- spzb 5y ago
  One less than usual at the moment though https://www.bbc.co.uk/news/uk-england-kent-58570893 https://www.bbc.co.uk/news/uk-england-kent-58570893

retrac 5y ago

Some coaxial lines were laid until the 1980s. Seems likely that at least one small island somewhere has a copper submarine cable supplying their data/phone needs still. But it's decidedly obsolete, yes.

sathackr 5y ago

Current fiber-containing submarine cables also have electrical lines to power inline amplifiers. Even fiber signals can't travel those kinds of distances without repeaters.