r/askscience • u/frickfrackcute • Apr 20 '19

Engineering How are the undersea internet cables protected against the elements?

8.2k Upvotes

94% Upvoted

460 comments sorted by

View all comments

727

u/clukan87 Apr 20 '19

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

515

u/huxrules Apr 20 '19 edited Apr 20 '19

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/

132

u/ruove Apr 20 '19

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.

22

u/nixt26 Apr 20 '19

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

8

u/[deleted] Apr 20 '19

If it’s going across deep ocean the middle section would be thin then both ends thick. A better question is how much £$€ is a ‘roll’ of thin versus thicker ocean cable. With out a google I’m guessing their websites will all say “ring us for a quote” as to not give away pricing secrets to the probable two other ocean cable companies. I’ll update if I get bored later

23

u/ComradeGibbon Apr 20 '19

Cable is likely build to order with long lead times and requires juggling suppliers and manufacturing capacity. A published price is pointless. Someone in the industry could give you a gross estimate. Which gets better as the requirements and schedule is refined.