How a subsea cable is repaired (2021)

https://www.onesteppower.com/post/subsea-cable-repair

by slicktux • 3 months ago

123 40 3 months ago

If you havent seen it, you owe it to yoiurself to read Mother Earth, Motherboard: https://www.wired.com/1996/12/ffglass/

A Neal Stephenson long read about undersea cables. So good!

y-curious• 3 months ago

About to read but your link is paywalled, here’s a copy: https://efdn.notion.site/Mother-Earth-Mother-Board-WIRED-a8f...

mett36• 3 months ago

thank you!

philipallstar4• 3 months ago

The British involvement, then, was more catalytic than anything else. They didn't own the rubber plantations. They merely bought the rubber on an open market from Chinese brokers who in turn bought it from producers of various ethnicities. The market was just a few square blocks of George Town where British law was enforced, i.e. where businessmen could rely on a few basics like property rights, contracts, and a currency.

In 2026 this is a surprisingly non-pearl clutching take on British influence abroad.

creinhardt• 3 months ago

Thanks, I loved this article, time to re-read it again!

For anyone who wants to know more about the early history of undersea cables, I also enjoyed ‘A Thread Across the Ocean’ by John Steele Gordon.

libraryofbabel• 3 months ago

Stephenson’s piece is a classic, but it was written in 1996, when things were very different in the tech industry and geopolitically. Much more up to date (and with an explicit debt to Stephenson) is Samanth Subramanian, The Web Beneath The Waves: The Fragile Cables that Connect our World. Well worth a read to see what’s changed since Stephenson.

chistev• 3 months ago

I've been using Hacker News to get book recommendations. Recently I started checking out the books mentioned in comments on topics I'm interested in learning more about.

I've added this book to my list, and it looks like a short read.

Thanks. Hope I like it.

walrus01• 3 months ago

Many of the weirder geopolitical parts like how large numbers of cables are all laid across Egypt to get from Europe to middle east -> south asia still remain significant factors. The part that is most dated is the cables being built by exclusively by big traditional telecom companies, when this was written in 1996 the idea of Microsoft or Google or Facebook or others bankrolling a submarine cable from Brazil to Europe was very far away.

The new and novel thing in 1996 from the author's perspective is cables being built not by a PTT type "telephone company" (the Bell System/AT&T, BT, France Telecom, etc) but a new entity that intended to build the cables to sell capacity to multiple telcos.

pchristensen2• 3 months ago

I'll have to check that out!

gnabgib• 3 months ago

(2021)

hallole• 3 months ago

This was a good read. I'm obsessed with undersea cables. I consider them one of the wonders of the modern world. Wikipedia says 99% of all internet traffic gets delivered via these ocean-spanning wires, just sitting along the sea floor. Almost unbelievable.

staticshock• 3 months ago

I can't believe this article does not mention what I think is the most puzzling part of the repair: the delicate process by which the individual fibers are FUSED TOGETHER in a way that maintains near perfect total internal refraction.

tambre• 3 months ago

You mean fusion splicing? That's common knowledge to anyone that's done any professional fibre cabling and you can easily find reading on it. The specifics of subsea cables however are much more elusive so it makes sense the article focuses on that.

dewey• 3 months ago

Also always interesting: https://www.submarinecablemap.com

rollulus• 3 months ago

Do they maintain the original connection between the fibers or is that not worth the effort and is a swap not a problem?

toast0• 3 months ago

I thought I had read that some cables have systems at each end to detect and correct when there's a splice with swapped cores, however, I can't find a reference; you could imagine such a system would mitigate partial breaks by assigning working paths to priority customers. However, I see a lot more about automatically aligning multicore fibers for splicing, I suspect proper alignment may be more practical than fixing it at the ends.

Even if it's not automated, the number of cores in multicore fibers tends to be pretty low, and there's a standard for marking fibers [1], that's similar-ish to the standard for marking copper pairs [2].

[1] https://en.wikipedia.org/wiki/TIA-598-C

[2] https://en.wikipedia.org/wiki/25-pair_color_code

lanewinfield• 3 months ago

I've been attempting to buy a cross section of one of these cables for a very long time. Anybody got a lead on one?

cucumber3732842• 3 months ago

Have someone with a .edu email address to email a company that makes them.

pvaldes• 3 months ago

If you sink a few old ships around in the area you will never need to repair it again each two years. Extra bonus if they are exactly the same ships that you found red-handed damaging the cables.

PoignardAzur• 3 months ago

tl;dr: They pull the damaged cable up, weld it to a new section of cable their brought, and then drop the cable with a detour to make room for the extra length.

(This is a really meandering article!)

torcete• 3 months ago

"Repeaters are included every 40-80 km to keep the signal strong."

Does it mean that there's a ton of repeaters under the sea? Where do they get the power from?

madaxe_again• 3 months ago

Along the same cable. Data cables usually carry power to some degree too, for their own use.

throawayonthe• 3 months ago

i believe they're simply powered by the electric conductors bundled with the cable

the extra interesting part i think is how they amplify the signal without having to decode it, just optically

https://en.wikipedia.org/wiki/Submarine_communications_cable...

namibj• 3 months ago

They are like bulbs on an old-school Christmas tree light string, all in series with just one insulated conductor between.

hmokiguess• 3 months ago

Cables can be tapped for information, or cut to drastically slow communication between countries. A greater emphasis on government protection of the cables may be in the future.

That left me wondering now, how would that even work? The wiretapping, that is

fsagx• 3 months ago

https://www.google.com/search?q=blind+mans+bluff+book

Has a good story of how it was done several decades ago. Not sure how it works these days.

t1234s• 3 months ago

Is it possible to tap into these cables for espionage purposes?

pingou• 3 months ago

"In 1858, when the first submarine cable was installed, sending a message across the Atlantic took nearly 18 hours."

If anyone is curious as to why it took so long: https://en.wikipedia.org/wiki/Transatlantic_telegraph_cable

TLDR: "smearing" of the signal (capacitance), no underwater amplifiers, very faint signal at the end.

ThinkingGuy• 3 months ago

I've read a number of articles on this topic, but there's one issue I've never seen addressed: With the large number of cables now in place, often with multiple cables running along similar paths, how great is the risk that in the course of raising up one end of a broken cable, you accidentally snag some other cable that was laid across the first cable after it was laid? Or is the ocean just so vastly, hugely, mind-bogglingly big that hardly any cables cross over each other?

How a subsea cable is repaired (2021)

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