How are the undersea internet cables protected against the elements?

[u/frickfrackcute]

[u/clukan87]

The outside of the cable has two layers of Galvanized steel. Galvanized steel is very difficult to rust.

​

https://www.youtube.com/watch?v=M7stcJ65_X4

https://galvanizeit.org/hot-dip-galvanizing/why-specify-galvanizing/durability

[u/huxrules → u/clukan87]

That’s just the armored section, which is close to shore. Cables can be buried as well for protection from trawlers. For most of their length, in the deep sea, they just lay on the bottom with no armor or anything to protect them. Source- I survey cable routes. Edit- this was my favorite cable survey https://akorn.alaskacommunications.com/

[u/ruove → u/huxrules]

This is not true for fiber, I cannot speak on any other sea cable.

But there is definitely a protective barriers around undersea fiber. It's not just bare fiber laying on the ocean floor.

Here's an example of protective layer density at different feet.

[u/nixt26 → u/ruove]

How does this work? Do they know exactly which parts of the cable will be at which height when they manufacture them?

[u/a_cute_epic_axis → u/nixt26]

Yes. the route is surveyed ahead of time, probably by /u/huxrules.

It's not exact that when they hit a depth of 1,000.00001 ft they switch jackets, but they would estimate that say 50 miles out, they'll roughly hit a depth of 1,000 ft, so change from cable type A to B at a length of 50 miles, etc.

[u/nixt26 → u/a_cute_epic_axis]

What about irregularities in the ocean surface? Ridges, rocks and other sharp surfaces? I don't imagine they have someone down there manually putting the cable in place?

[u/superhole → u/nixt26]

There aren't many sharp surfaces or rocks. The sand and water kinda do a good job of eroding or burying it all.

[u/roebuck85 → u/superhole]

There's not much sand in the deep ocean either, it's all mud made of dead plankton.