41–50 of 61 posts
Were they cut on purpose or accident?
A captain told me once that it is silly to assume a big ship dropps it’s anchor accidentally unnoted
And red sea is quite sunny currently (i just checked windy.com now) . There is absolutely no reason that they need to drop it out of nowhere.
Earlier quoted context omitted.
In most cases they can easily figure out approximately where the break is on the line by simply measuring the resistance in the cable's conductors (they have more than one but the big one caries a 10,000V feed to power the repeaters). A double cut would probably show up as resistances that didn't sum to the proper total.
You can only practically do that optically e.g through OTDR. You can't TDR steel conductors exposed to the ocean 500KM away with a ohm meter and a Murray loop, to even have a chance you need to put low voltage on it and it's not even close to as accurate.
https://en.m.wikipedia.org/wiki/Murray_loop_bridge
Spread-spectrum time-domain reflectometry (SS-TDR) is often used to locate and characterize a fault on active cables. Traditional time-domain reflectometry, which sends signals down a conductor to determine where any impedance discontinuities are by timing any reflections that come back from any impedance discontinuities along the way, can’t be used on in-use undersea cables thanks to the high voltages involved. SS-TDR, which was originally developed to detect faults in the wiring of airplanes using 400-Hz AC power, uses modulated pseudo-noise (PN) signals rather than a plain square wave pulse. The signals still bounce off any impedance changes introduced by damage, but an algorithm is used to correlate the returned PN codes with what was sent and when, making it easier to make measurements in a noisy environment. Optical TDR can also be used to locate fiber breaks
A little knowledge goes a long way
Earlier quoted context omitted.
https://www.bbc.com/future/article/20241014-the-deep-sea-eme... An article about people who fix this Also, the teams are quite busy: > "There are 150 to 200 instances of damage to the global network each year. So if we look at that against 1.4 million km, that's not very many, and for the most part, when this damage happens, it can be repaired relatively quickly." ... > If a fault is found, a repair ship is dispatche…
> 1.4 million km Strange way of writing 1.4gm.
Earlier quoted context omitted.
https://www.bbc.com/future/article/20241014-the-deep-sea-eme... An article about people who fix this Also, the teams are quite busy: > "There are 150 to 200 instances of damage to the global network each year. So if we look at that against 1.4 million km, that's not very many, and for the most part, when this damage happens, it can be repaired relatively quickly." ... > If a fault is found, a repair ship is dispatche…
I wonder how much slack is left in the cable over its run in order to facilitate bringing it up for repair.
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> Cables in Red Sea got cut frequently On land, we’ve call before you dig . I wish they could do something like call before you drop (anchor) training or just get the word out.
They are usually marked on nautical charts.
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(It’s not actually anchors.)
Why do you say that? I can't say I'm an expert on the matter, but my understanding from industry reporting on some likely intentional ones in the Baltic where that they were still unambiguously done with anchors. Just by someone intentionally causing the anchor to drop and drag along.
Can they splice these? Surely the don't have to run a whole new cable?
They can but it's an involved process. Modern cables manage their slack very precisely - a complicated job in and of itself - and usually cannot be hauled to the surface without snapping them. So if the cable is not already cut (an anchor can damage a cable in a variety of ways short of physically snapping it) it will be cut while still on the bottom. The ends are then winched up and a splice is patched in but now th…
Earlier quoted context omitted.
https://www.bbc.com/future/article/20241014-the-deep-sea-eme... An article about people who fix this Also, the teams are quite busy: > "There are 150 to 200 instances of damage to the global network each year. So if we look at that against 1.4 million km, that's not very many, and for the most part, when this damage happens, it can be repaired relatively quickly." ... > If a fault is found, a repair ship is dispatche…
> 1.4 million km Strange way of writing 1.4gm.