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Repair Crews Reach Vicinity of Damaged Cables In Mediterranean

timothy posted more than 5 years ago | from the now-we-need-a-plucky-diver dept.

The Internet 145

GWMAW writes "A robotic submarine searched beneath the Mediterranean on Sunday for damaged communications cables, two days after Web and telephone access was knocked out for much of the Middle East. Telecommunication providers from Cairo to Dubai continued Sunday to scramble to reroute voice and data traffic through potentially costly detours in Asia and North America after the lines running under the Mediterranean Sea were damaged Friday." According to the article, "Once found, the cable ends will be pulled to the surface and repaired on deck — a process that could take several days."

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Maybe this time ... (0, Offtopic)

nategoose (1004564) | more than 5 years ago | (#26213441)

... they will find Gilligan's Island and rescue the castaways.

Re:Maybe this time ... (3, Funny)

pipboy9999 (1088005) | more than 5 years ago | (#26213475)

... they will find Gilligan's Island and rescue the castaways.

And then whom ever owns the copy right to Gilligan's Island will misread the headline and sue them for using the under sea cable to download episodes of Gilligan's Island

Re:Maybe this time ... (2, Funny)

internetcommie (945194) | more than 5 years ago | (#26213639)

In the age of the intarwebs undersea piracy has replaced piracy on the high seas!

Re:Maybe this time ... (0)

Anonymous Coward | more than 5 years ago | (#26213825)

Use "whoever", not "whom ever" in that situation.

Re:Maybe this time ... (1)

Yvan256 (722131) | more than 5 years ago | (#26213703)

I bet 10$ that it's Gilligan who cut the cables by accident.

Re:Maybe this time ... (1)

morgauo (1303341) | more than 5 years ago | (#26214079)

That's $10 for each of us right?

Re:Maybe this time ... (0, Redundant)

Theoboley (1226542) | more than 5 years ago | (#26214177)

I bet he used a coconut to cut them... They use coconuts for everything else on that show.

Gilligan Saved the Cable! (2, Informative)

camperdave (969942) | more than 5 years ago | (#26214223)

Gilligan didn't cut the cable, the Professor did. He made a saw out of Mrs Howell's diamonds to try to cut through the outer sheath of the cable. When that didn't work, he rigged a blow torch to burn/melt his way through to the wires. All Gilligan did was cover up the hole with tree sap when the storm hit again. He *SAVED* the cable.

Re:Gilligan Saved the Cable! (1)

Lord Apathy (584315) | more than 5 years ago | (#26215629)

I always wondered why didn't they just cut the fucking cable, tie it off, and wait for a repair ship to show up? But then again they where trapped on that island for 15 years and to god damn stupid to build a boat. The professor could pull a fusion reactor out of his ass but couldn't fix a god damn boat engine.

meh (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#26213533)

this story sucks. Please post something about Barack Obama's ripped abs.

Remember (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26213535)

The goatse. [goatse.fr]

Dang! I was getting SUCH a good deal (5, Funny)

HawkinsD (267367) | more than 5 years ago | (#26213537)

Dang it! I was getting SUCH a good deal from the colocation facility in Yemen.

Wow (4, Funny)

papasui (567265) | more than 5 years ago | (#26213553)

Stop pissing off Andrew Ryan.

How do they do it? (5, Interesting)

tsa (15680) | more than 5 years ago | (#26213609)

How do they repair the cables? Especially with glass fibre I wouldn't know what to do.

Re:How do they do it? (4, Funny)

John Hasler (414242) | more than 5 years ago | (#26213675)

> How do they repair the cables?

Superglue and duct tape.

Re:How do they do it? (4, Funny)

TheGratefulNet (143330) | more than 5 years ago | (#26213681)

this is for UNDER WATER use.

therefore, its better left to DUCK tape.

(sorry....)

Re:How do they do it? (2, Funny)

CODiNE (27417) | more than 5 years ago | (#26214645)

Surely not! We all know here that ducks float.

Re:How do they do it? (0)

Anonymous Coward | more than 5 years ago | (#26215033)

Only live ducks float.

Re:How do they do it? (1, Funny)

Anonymous Coward | more than 5 years ago | (#26215695)

Surely not! We all know here that ducks float.

So we use witch tape?

Re:How do they do it? (2, Funny)

Yvan256 (722131) | more than 5 years ago | (#26213749)

Red Green [wikipedia.org] to the rescue!

Re:How do they do it? (2, Interesting)

Aphoxema (1088507) | more than 5 years ago | (#26213763)

I'm sure it's possible to cut off clean ends and put a replacement between, possible install a repeater in between. The beam already has to be extremely powerful to cross hundreds of miles, another cut shouldn't cause too much attenuation.

I just hate to think what happens if this happens too many times, they'll have to lay a whole new cable.

Re:How do they do it? (1)

c1t1z3nk41n3 (1112059) | more than 5 years ago | (#26213919)

or just a new section. If you assume that most breaks in the cable occur in fairly localized areas due to increased environmental stresses, increased ship traffic or what have you then you may be able to replace a 50 mile section of cable with say 4 or 5 breaks in it and the new section would have 2 breaks. Of course that assumption may not play out though it seems reasonable to me. Also it would still be a stopgap as you would then see further breaks in that same section over time.

Re:How do they do it? (1)

ubrgeek (679399) | more than 5 years ago | (#26213941)

Why not drop an amplifier between the two parts? That way you're not syncing the cable to another piece of cable. Rather to a device in the middle?

Re:How do they do it? (2, Insightful)

ByOhTek (1181381) | more than 5 years ago | (#26214019)

how do you propose to power it?

I'm not saying power couldn't be supplied, but I don't think it'd be cost effective, and you'd need to run a whole new set of lines.

Re:How do they do it? (1)

ubrgeek (679399) | more than 5 years ago | (#26214101)

I guess that's what a liberal-arts major gets for throwing a comment into a technical discussion: I hadn't even thought of that :)

Re:How do they do it? (4, Informative)

tabrisnet (722816) | more than 5 years ago | (#26214457)

Actually, there are repeaters in line, albeit I don't remember the distances. There's a big copper conductor in the jacket (just one, the ground is the ocean itself) sending a couple hundred volts through it.

Re:How do they do it? (3, Informative)

lucifuge31337 (529072) | more than 5 years ago | (#26215395)

how do you propose to power it?

I'm not saying power couldn't be supplied, but I don't think it'd be cost effective, and you'd need to run a whole new set of lines.

The same way the repeaters are already powered - the are power leads bundled with the fiber cable. In a full cut, they would have to repair the copper power leads anyway.

Re:How do they do it? (1)

ByOhTek (1181381) | more than 5 years ago | (#26215851)

I didn't know they already did that.

Taking on the GP's reply to my post...

I guess that's what a Biological/Computer Science major gets for posting on an electrical/(civil?) engineering topic.

Re:How do they do it? (1)

mpe (36238) | more than 5 years ago | (#26214793)

Why not drop an amplifier between the two parts? That way you're not syncing the cable to another piece of cable. Rather to a device in the middle?

You'd still have to dismantle the cable and clean up the fibres anyway. An anchor is not going to make any kind of clean cut. So the task of splicing an any kind of repeater is going to be just as complex as joining the cable back together. Even before you consider the problem of powering that repeater.

Re:How do they do it? (5, Informative)

rickb928 (945187) | more than 5 years ago | (#26213911)

The actual fiber repair is done pretty much as it would be done for terrestrial cables. Either a fusion splice, usually by re-cleaving the ends for a clean surface and vibrating the ends ultrasonically to heat by friction and weld them together, or a very small splicing kit that holds the ends in near-perfect alignment, usually filled with a gel of identical optical properties to reduce the loss and refraction. Since space is an issue, I suspect fusion splices are the only acceptable option.

The biggest problem is both accomodating the repairs to the fiber jackets, and then re-sealing the cable. I wouldn't be suprised that there are fairly standard splice boxes that solve this.

Replacing segments doesn't seem like a good option. Any useful segment should measure miles in length, which is pretty expensive. Even replacing a segment and hauling the old one in for repair sounds like more trouble than it's worth. Of course, repairs on the open sea sound like fun to me. I had enough trouble sitting at a little worktable in a dim cable room with equipment balanced here and there, and testing going on constantly. A nice 20-30 foot sea would make me want to apply at the local McDonald's. Life is too short.

But nice work if you can do it.

Re:How do they do it? (1)

Sinus0idal (546109) | more than 5 years ago | (#26215249)

Haha you joke, but I've actually opened a cabinet before to find a broken fibre taped up with a note on it saying 'inline splice, don't touch'. If you nudged it, the connection went down! Quality.

Re:How do they do it? (1)

internetcommie (945194) | more than 5 years ago | (#26213683)

Superglue? Duct tape? Or maybe that magic stuff they use to make cracks in car windshields go away?

Re:How do they do it? (1)

xSauronx (608805) | more than 5 years ago | (#26214799)

new windshields? *confused*

Re:How do they do it? (5, Funny)

Anonymous Coward | more than 5 years ago | (#26213685)

Don't worry, you don't have to do a thing. They already have people who do know what to do.

Re:How do they do it? (1)

Turiko (1259966) | more than 5 years ago | (#26213691)

Well, i guess they just cut off the 2 damaged parts, put a decent ender on it (like utp cables have a clip) and just put in another piece with 2 enders on them, and they put them together. The only problem is that that cable was never meant to be like that, and thus the protective layer around it is hard to break... at least when they try to repair it :D

Re:How do they do it? (0)

Anonymous Coward | more than 5 years ago | (#26213693)

ala google
http://www.lanshack.com/fiber-optic-tutorial-termination.aspx
multiply * a few dozen - hundred and possibly do it twice to add in a length of cable.

Re:How do they do it? (1)

jellomizer (103300) | more than 5 years ago | (#26213731)

That is why you are not doing it.

I am not an expert myself. However Glass does Melt, and can be fused back together, is a possibility, or the ends polished and put right next to each other... Perhaps there is a lot of Dark Fiber built into the cable to be bypassed. Humans made the technology, they probably know how to fix it.

Re:How do they do it? (1)

mpe (36238) | more than 5 years ago | (#26214887)

I am not an expert myself. However Glass does Melt, and can be fused back together, is a possibility, or the ends polished and put right next to each other...

Stuck together with a glue having similar optical properties IIRC

Re:How do they do it? (1)

kimvette (919543) | more than 5 years ago | (#26215833)

A typical rule of thumb is to bundle twice the number of fibers that you actually need. In an undersea cable, I wouldn't be surprised if they include four or even ten times what is needed to take occasional breaks and even future expansion into account. However, no amount of dark fiber will help when the whole bundle is severed by saboteurs^H^H^H^H^H^H^H^H^Hanchors.

Re:How do they do it? (5, Informative)

pipboy9999 (1088005) | more than 5 years ago | (#26213755)

How do they repair the cables? Especially with glass fibre I wouldn't know what to do.

My assumption would be that there are points built into the cable where you can exchange out bad segments for new segments.

Re:How do they do it? (4, Informative)

Anonymous Coward | more than 5 years ago | (#26213771)

http://www.laser2000.co.uk/fusion_splicers.php?area=262

Re:How do they do it? (2, Funny)

ColdWetDog (752185) | more than 5 years ago | (#26214831)

I knew it! Sharks with Lasers! We don't need any stupid submarines.

Re:How do they do it? (2, Interesting)

davidsyes (765062) | more than 5 years ago | (#26213931)

It would be interesting if they could build a cofferdam to house the bad ends and conduct repairs in it.

Say each segment is some 300 feet long. One or more cofferdams of such length could be built and kept on stand-by. When a cable is damaged or cut in some way, the cofferdams (maybe similar to a submarine or coffin with hinges on one side so that the other open and close to admit the cable. The bad ends would be trimmed off and given new ends, and the cofferdam unlocked and flooded and dragged aside, or the cable dragged out from the opened cofferdam.

Admittedly, the cofferdam might have to be as big as a small submarine (say, 33' in diameter) and include local power supply, air generation, and resting areas for the crew, as well as rapid escape gear. This thing might have to survive extreme depths of around 5,000 feet. But, it won't be rated for combat, shock, and so on, but any 1.5 to 1.9 survival factor (similar to USN submarines) might be good enough since the cofferdam would be towed and ballasted down to the rated working depting.

Possibly even better might be a huge half-pipe that is massively heavy enough to semi-protect workers who are in advanced work suits. But, the nice thing about a mobile clamshell/decomissioned sub-like hull is the crew would be working at depth without suits, pressurized like sub crews, and avoid decompression routines.

Re:How do they do it? (0)

Anonymous Coward | more than 5 years ago | (#26214053)

Are you insane?

There is enough slack in the cable to simply hook it, pull it up to the surface and do the repair on the deck of a ship in that wonderful thing we call atmosphere and not a crazy expensive submarine.

Re:How do they do it? (1)

zippthorne (748122) | more than 5 years ago | (#26215369)

Not really that useful. A cofferdam will just slice the cable just outside the wall when you drive the steel elements into the seabed. Also, it'll take weeks or months to set up and break down, and doesn't work in water deeper than a few hundred feet, anyway.

Now you could use a caisson or dive bell to do the repairs, but then you have the issue of damaging workers' health in long saturation dives, and you have to spend long time getting guys up and down to the work site.

The best option is the one they do: hook both ends of the cable and drag them up to the tender, lock it in to your mobile clean room and take your time. It's just like your clamshell plan, except there's no risk of crimping the cable, and no need for a heavy pressure hull.

Re:How do they do it? Thx... (1)

davidsyes (765062) | more than 5 years ago | (#26215771)

Doesn't help either that i forgot to mention a need for packing glands, sort of like in stern tubes for ships' propeller shafts. these could be air or oil-filled (environmental issues aside...regarding the oil) and inflated to seal out the water.

But, thanks for commenting.

An aside. I'm going to assume that some (pick your favorite) government attacked the cable, but in more than one place. The public, compromised area is the one we read about. The other, presumed undetected attack is where a tap was placed. Some kind of tap many geeks here would claim doesn't or cannot exist. But, i say, "Never say never". People these days get paid very big (or maybe not very big) money to circumvent others' communication systems, sorta the inverse of that ex-Radioman named Walker, who compromised the KW-7 crypto keying secrets for a measely sum.

Re:How do they do it? (1, Informative)

Anonymous Coward | more than 5 years ago | (#26213775)

How do they repair the cables? Especially with glass fibre I wouldn't know what to do.

http://www.francetelecom.com/sirius/dossiers_anim/cables_sous_marins/index_en.html

Re:How do they do it? (3, Interesting)

au3276f8ads7bfsad76s (878200) | more than 5 years ago | (#26213785)

Better yet, how do they find where it's broken? I'm assuming you can't just 'ping' the broken end and get a distance measurement...

Re:How do they do it? (5, Informative)

onkelonkel (560274) | more than 5 years ago | (#26213865)

You had it right. OTDR.

Optical Time Domain Reflectometer. You just ping the broken end and get a distance measurement.

Standard fare on good network testers (2, Interesting)

Sycraft-fu (314770) | more than 5 years ago | (#26214665)

I used to work at a network operations centre and we had testers that did all the kind of stuff. They'd tell you how long a cable was, what the loss was, if there was a break, info about the other end, etc, etc. Also could do layer 2 and 3 diagnostics. It was a real useful tool if a connection didn't work. Plug it in, see what looked out of place.

Re:How do they do it? (1)

nostrad (879390) | more than 5 years ago | (#26213867)

You can, that's the good part about it, many times signals reflect when they hit an improperly terminated connection (impendance mismatch). This holds for both optical and electrical signals. Given the propagation time and speed, length is trivially calculated. There's special hardware to do this for you. See also: http://en.wikipedia.org/wiki/Impedance_mismatch [wikipedia.org]

Re:How do they do it? (-1, Redundant)

Anonymous Coward | more than 5 years ago | (#26213877)

sure you can. google OTDR (Optical Time Domain Reflection). You get a fraction of a second value and multiply * speed of light in a fiber and voila, #feet to break.

Re:How do they do it? (4, Informative)

Octorian (14086) | more than 5 years ago | (#26213881)

With a device known as an Optical Time Domain Reflectometer [wikipedia.org] . Supposedly they can not only detect cable length, breaks, but even the location of splices.

Re:How do they do it? (1)

aphexer (1110553) | more than 5 years ago | (#26214151)

Indeed, any piece of fiber which isn't of very good quality will reflect part of the transmitted optical signal. By measuring these reflections with an OTDR like you said, you can pin-point the exact location of the damaged fiber. Even a splice of very good quality creates a little loss (about 0.10 dB), which you can measure.

Measurement with an OTDR is basically an optical radar. Send out an optical pulse and measure what comes back. Do some heavy math and you can plot signal loss vs cable length.

One hard part of this is that you need the exact refractive index of the glass you used (and you need several decimals...). This refractive index is used to calculate the distance the light has traveled before reflecting. If this index is just a bit off, then you're off hundreds of meters.

Re:How do they do it? (1)

John Hasler (414242) | more than 5 years ago | (#26213889)

Well you can, in a way. A pulse of light will be partially reflected from the broken end and the round-trip time measured. You should also be able to detect the last repeater in each half and so isolate the break to segment between the repeaters. There is also copper wire in the cable to power the repeaters and it should be possible to figure out how far the break in it is from the shore station by several methods.

IMHO the operators need to give more thought to reliability. They need more space diversity. The cables should be seperated, especially at landings and in shallow areas, and they should be plowed in in shallow areas. This would cost more money, though.

Re:How do they do it? (2, Informative)

AdamHaun (43173) | more than 5 years ago | (#26214183)

Actually, you can. You use a device called a Time Domain Reflectometer [wikipedia.org] , which sends a pulse down the line and times how long it takes a reflection to come back.

2 * Distance = Speed of light * Round trip time

To find the location of the fault to within ten feet you need a timer with about a 20 nanosecond resolution, which equates to a 50 MHz counter -- not too difficult.

Re:How do they do it? (4, Informative)

AngelCeleste (1035358) | more than 5 years ago | (#26213787)

fiber splicers - its mostly done in the field because in house we have handy-dandy prespliced fiber cables of different lengths. If you see (fill in local ILEC) out repairing a cut cable, chances are they might be splicing.

Re:How do they do it? (5, Informative)

Anonymous Coward | more than 5 years ago | (#26214007)

How do they repair the cables? Especially with glass fibre I wouldn't know what to do.

They drag the cable up and cut it (assuming it is not already in two pieces). They strip back the armor and sheath on both pieces. They then splice in a new piece of cable using a fusion splicer, which basically lines up each individual fiber (quite a time-consuming process to clean and prep each piece) and then the fusion splicer essentially melts the fiber strand back together. They put heat-shrink and something like a splint to keep it from bending over the spliced area and then fit each splice into a tray. The trays are then mounted into a splice case. Submarine cables are much more difficult because it has to be well sealed and able to withstand significant pressure.

The faults are located using an OTDR (Optical Time Delay Reflectometry), which basically sends light down the fiber and measures the reflections. As we know the speed of light we can accurately measure the distance to a break, imperfections, etc of the cable and splices.

Re:How do they do it? (3, Informative)

aphexer (1110553) | more than 5 years ago | (#26214073)

They cut the cable in half, and put a new piece in it. They can locate the exact point of failure using an OTDR, as already mentioned in other comments by now.

In one such big under-sea cable, there could be hundreds of individual fibers inside. (It doesn't cost alot more to put another fibre in the big cable, and you get alot more bandwidth to sell).

For each fiber inside the cable they "weld" it to the new piece they are putting between. (I'm sorry, I don't have the correct translation for the word in English). But really, they put the fiber in a machine, together with the fiber of the new cable they are putting in between, and they hit a button: "weld". It creates an arc through the point where the fiber needs to be welded together. After the arcing you heat that spot so the atomic structure can repair a little.

Repeat 500 times and put some extra mechanical protection around to protect your welding, and you're done.

There exists equipment that can do multiple fibers at once, so basically the engineer who's doing it just needs to place both ends of the fibers in the machine, hit the button, remove fiber and repeat for a day or 2.

Re:How do they do it? (3, Insightful)

joeslugg (8092) | more than 5 years ago | (#26214279)

I'm wondering about the "pulled to the surface and repaired on deck" part.

I imagine a cable laying on the sea floor going more or less "straight"
from A to B. Is there enough slack in the line to bring the broken
ends to the surface and hold them together?

(Clearly, the answer must be 'yes'. But I'm just wondering if anyone knows
more about it. Do they intentionally leave in some slack just for such a
reason when they lay a cable like this?)

Re:How do they do it? (1)

ColdWetDog (752185) | more than 5 years ago | (#26214999)

(Clearly, the answer must be 'yes'. But I'm just wondering if anyone knows more about it. Do they intentionally leave in some slack just for such a reason when they lay a cable like this?)

If you think about it, given the long length of the cable compared to the depth of the ocean floor, you aren't adding much the total length of the run buy taking it to the surface. You could easily have some slack in the system to accommodate this. And of course, the cable is cut, so you might just add a new splice section to 'make up the slack' if needed. The couple of articles [slate.com] I found didn't really address your question, though.

Re:How do they do it? (1)

zymano (581466) | more than 5 years ago | (#26214329)

lift it and then melt the fiber.

Re:How do they do it? (1)

Unique2 (325687) | more than 5 years ago | (#26214359)

When the BT engineer installed my companies fibre based connection, they did this [youtube.com] , it's probably just as awesome but on a larger scale.

Re:How do they do it? (1)

UNKN (1225066) | more than 5 years ago | (#26214437)

They most likely will have to splice each and every fiber, they pretty much line them up and then glue them together...that of course is a very basic idea of what they do, I don't work with the installers, I've just seen them do it, pretty neat.

Re:How do they do it? (0, Redundant)

mpe (36238) | more than 5 years ago | (#26214699)

How do they repair the cables? Especially with glass fibre I wouldn't know what to do.

I would imagine by splicing each fibre and replacing the sheaths as they go.

Re:How do they do it? (2, Informative)

Anonymous Coward | more than 5 years ago | (#26215185)

Ok, I'll bite.

Optical fiber cables are connected by first identifying each strand in the bundle, and the other cut end of that same strand. Matching strands are taken, one set at a time, into a fusion splicing machine. The fusion splicing machine aligns the strands, then heats the ends so the glass melts together.

Older splicing machines required the person operating the machine to visually ensure the strands were aligned, and the heating was automatic. New machines perform computer-guided alignment and automatic heating. These machines commonly cost about as much as a nice new car (around $30-50 thousand U.S. dollars, IIRC) and require specialized training and supplies for regular, telephone-pole mounted cables. Undersea cables probably have extra special costs.

In any case, a bundle with hundreds of strands takes days to repair. It can take several hours to splice a broken 36 strand cable.

You can only get so many machines close enough to the broken cable, so the work does not allow for, say, 50 splicers to all work on it at once.

Of course, I'm glossing over all the work it takes to pull a cable off the sea floor, get it on a ship, and then put it back. Someone else can gather karma for that info ;)

Re:How do they do it? (1)

kimvette (919543) | more than 5 years ago | (#26215755)

They use something called a "fusion splicer" to weld the fibres together.

and while you're at it (1, Troll)

binkleybloom (1291162) | more than 5 years ago | (#26213831)

stop using seal blubber for the dielectric!

Slack (2, Interesting)

terraformer (617565) | more than 5 years ago | (#26213913)

There has to be a lot of slack for them to be able bring up both ends and not require massive amounts of force or cause stress on the ends. I wonder if they lay the cable not straight but in shallow s-turns back and forth to introduce slack into the system.

Re:Slack (0)

Anonymous Coward | more than 5 years ago | (#26214275)

I didn't even think of that. Pulling a cable up probably increases the odds of damage to other sections of the cable.

Re: Slack (5, Informative)

Civil_Disobedient (261825) | more than 5 years ago | (#26214289)

There was a terrific article written for Wired by Neal Stephenson (yes, that Neal Stephenson!) called Mother Earth Mother Board [wired.com] all about the laying of the longest underwater telephony cable in history. He goes into a lot of details as to how the cable is laid, what happens to the cable when it reaches shore, what is the cable made of, how does it work, etc.

Here's an excerpt where he explains how slack affects the process:

The basic problem of slack is akin to a famous question underlying the mathematical field of fractals: How long is the coastline of Great Britain? If I take a wall map of the isle and measure it with a ruler and multiply by the map's scale, I'll get one figure. If I do the same thing using a set of large-scale ordnance survey maps, I'll get a much higher figure because those maps will show zigs and zags in the coastline that are polished to straight lines on the wall map. But if I went all the way around the coast with a tape measure, I'd pick up even smaller variations and get an even larger number. If I did it with calipers, the number would be larger still. This process can be repeated more or less indefinitely, and so it is impossible to answer the original question straightforwardly. The length of the coastline of Great Britain must be defined in terms of fractal geometry.

A cross-section of the seafloor has the same property. The route between the landing station at Songkhla, Thailand, and the one at Lan Tao Island, Hong Kong, might have a certain length when measured on a map, say 2,500 kilometers. But if you attach a 2,500-kilometer cable to Songkhla and, wearing a diving suit, begin manually unrolling it across the seafloor, you will run out of cable before you reach the public beach at Tong Fuk. The reason is that the cable follows the bumpy topography of the seafloor, which ends up being a longer distance than it would be if the seafloor were mirror-flat.

Over long (intercontinental) distances, the difference averages out to about 1 percent, so you might need a 2,525-kilometer cable to go from Songkhla to Lan Tao. The extra 1 percent is slack, in the sense that if you grabbed the ends and pulled the cable infinitely tight (bar tight, as they say in the business), it would theoretically straighten out and you would have an extra 25 kilometers. This slack is ideally molded into the contour of the seafloor as tightly as a shadow, running straight and true along the surveyed course. As little slack as possible is employed, partly because cable costs a lot of money (for the FLAG cable, $16,000 to $28,000 per kilometer, depending on the amount of armoring) and partly because loose coils are just asking for trouble from trawlers and other hazards. In fact, there is so little slack (in the layperson's sense of the word) in a well-laid cable that it cannot be grappled and hauled to the surface without snapping it.

This raises two questions, one simple and one nauseatingly difficult and complex. First, how does one repair a cable if it's too tight to haul up?

The answer is that it must first be pulled slightly off the seafloor by a detrenching grapnel, which is a device, meant to be towed behind a ship, that rolls across the bottom of the ocean on two fat tractor tires. Centered between those tires is a stout, wicked-looking, C-shaped hook, curving forward at the bottom like a stinger. It carves its way through the muck and eventually gets under the cable and lifts it up and holds it steady just above the seafloor. At this point its tow rope is released and buoyed off.

The ship now deploys another towed device called a cutter, which, seen from above, is shaped like a manta ray. On the top and bottom surfaces it carries V-shaped blades. As the ship makes another pass over the detrenching grapnel, one of these blades catches the cable and severs it.

It is now possible to get hold of the cut ends, using other grapnels. A cable repair ship carries many different kinds of grapnels and other hardware, and keeping track of them and their names (like "long prong Sam") is sort of like taking a course in exotic marine zoology. One of the ends is hauled up on board ship, and a new length of cable is spliced onto it solely to provide excess slack. Only now can both ends of the cable be brought aboard the ship at the same time and the final splice made.

But now the cable has way too much slack. It can't just be dumped overboard, because it would form an untidy heap on the bottom, easily snagged. Worse, its precise location would not be known, which is suicide from a legal point of view. As long as a cable's position is precisely known and marked on charts, avoiding it is the responsibility of every mariner who comes that way. If it's out of place, any snags are the responsibility of the cable's owners.

So the loose loop of cable must be carefully lowered to the bottom on the end of a rope and arranged into a sideways bight that lies alongside the original route of the cable something like an oxbow lake beside a river channel. The geometry of this bight is carefully recorded with sidescan sonar so that the information can be forwarded to the people who update the world's nautical charts.

One problem: now you have a rope between your ship's winch and the recently laid cable. It looks like an old-fashioned, hairy, organic jute rope, but it has a core of steel. It is a badass rope, extremely strong and heavy and expensive. You could cut it off and drop it, but this would waste money and leave a wild rope trailing across the seafloor, inviting more snags.

So at this point you deploy your submersible remotely operated vehicle (ROV) on the end of an umbilical. It rolls across the seabed on its tank tracks, finds the rope, and cuts it with its terrifying hydraulic guillotine.

Sad to say, that was the answer to the easy question. The hard one goes like this: You are the master of a cable ship just off Songkhla, and you have taken on 2,525 kilometers of cable which you are about to lay along the 2500-kilometer route between there and Tong Fuk Beach on Lan Tao Island. You have the 1 percent of slack required. But 1 percent is just an average figure for the whole route. In some places the seafloor is rugged and may need 5 percent slack; in others it is perfectly flat and the cable may be laid straight as a rod. Here's the question: How do you ensure that the extra 25 kilometers ends up where it's supposed to?

Remember that you are on a ship moving up and down on the waves and that you will be stretching the cable out across a distance of several kilometers between the ship and the contact point on the ocean floor, sometimes through undersea currents. If you get it wrong, you'll get suspensions in the cable, which will eventually develop into faults, or you'll get loops, which will be snagged by trawlers. Worse yet, you might actually snap the cable. All of these, and many more entertaining things, happened during the colorful early years of the cable business.

The answer has to do with slack control. And most of what is known about slack control is known by Cable & Wireless Marine. AT&T presumably knows about slack control too, but Cable & Wireless Marine has twice as many ships and dominates the deep-sea cable-laying industry. The Japanese can lay cable in shallow water and can repair it anywhere. But the reality is that when you want to slam a few thousand kilometers of state-of-the-art optical fiber across a major ocean, you call Cable & Wireless Marine, based in England. That is pretty much what FLAG did several years ago.

Re: Slack (1)

exhilaration (587191) | more than 5 years ago | (#26214897)

Terrific article indeed. Thanks for posting it.

Re: Slack (0)

Anonymous Coward | more than 5 years ago | (#26215065)

[...] before you reach the public beach at Tong Fuk.

The interesting part is they didn't mention that said beach is a nude beach... or was that implied?

Re: Slack (1)

ColdWetDog (752185) | more than 5 years ago | (#26215149)

Oh, well. Since Neal's on the case, we can just go home and forget about doing random Google searches. But doing so finds that Cable and Marine systems seemingly has been bought out by Global Marine [globalmarinesystems.com] . Might be a fun place to work.

Re: Slack (1)

pi_rules (123171) | more than 5 years ago | (#26215161)

I never knew laying cable could be so interesting.

Conspiracy Theory (2, Interesting)

Anonymous Coward | more than 5 years ago | (#26213947)

If I was a certain US entity who is worried about more and more internet traffic avoiding the ol' USA, I'd "damage" a cable while using the outage as a cover to put a tap a few hundred miles away. If anything goes awry while tapping the cable, the obvious damage will be labeled as the cause.

But that's just me.

Re:Conspiracy Theory (1)

tchdab1 (164848) | more than 5 years ago | (#26214361)

Yes, the operant question for me in this story is "did we/the CIA cut the cable, did some other entity do it, or was it an accident?"
Not a whole lot of clues to go on so far.
And I wish I had some links to stories of various cable capers we (the USA) have been involved in before show those encountering this possibility for the first time.

Re:Conspiracy Theory (1)

afabbro (33948) | more than 5 years ago | (#26215293)

Yes, the operant question for me in this story is "did we/the CIA cut the cable, did some other entity do it, or was it an accident?"

If that's what you're focusing on, then the operant question for you should be "is my tin foil thick enough?"

Satellites FTW? (1)

BiggoronSword (1135013) | more than 5 years ago | (#26214055)

Yet another reason why we need a better satellite infrastructure. If everyone were using satellites, a reroute through Asia would be unnecessary.

Re:Satellites FTW? (1)

WPIDalamar (122110) | more than 5 years ago | (#26214145)

~500ms Latency.

Re:Satellites FTW? (1)

Sethb (9355) | more than 5 years ago | (#26214171)

Yes, but satellite internet pretty much kills any possibility of internet gaming, other than turn-based games. Wikipedia says it adds 500 to 900 miliseconds, which, erm, would suck.

Re:Satellites FTW? (5, Interesting)

karmatic (776420) | more than 5 years ago | (#26214175)

Yet another reason why we need a better satellite infrastructure. If everyone were using satellites, a reroute through Asia would be unnecessary.

Except for the whole "240ms minimum latency" thing. Also, it's a lot easier to fix a malfunctioning cable than a malfunctioning satellite. Also, bad weather over the Satellite NOC can take out everyone's connection.

Re:Satellites FTW? (2, Informative)

hardburn (141468) | more than 5 years ago | (#26214245)

Geosychronous orbit has too much time latency, and LEO takes more satellites to cover the same area. It'd be cheeper to just lay more cable, but corporations tend to push for raw efficiency rather than redundancy. It's going to take governments using their buying power to encourage redundant routes to get us back to where DARPA was in the '80s.

Re:Satellites FTW? (1)

Matz0r (324905) | more than 5 years ago | (#26214739)

My company has some servers located on Malta, we were down for about 8 hours before they could re-route the traffic. Ironically, we have better routing through Europe now than before the break.

Re:Satellites FTW? (1)

ChrisA90278 (905188) | more than 5 years ago | (#26215873)

People don't like satellite links. Some people don't like then so much that they will hang up and re-dial hoping to get routed over a cable next try. The reason is the delay. Light is fast but geo-sync is high. It's annoying to have a lag in the phone conversation so cables are always preferred.

Not necessarily a single point of failure. (1)

Tibor the Hun (143056) | more than 5 years ago | (#26214075)

I don't think this is a single point of failure. Now, of course I didn't read the article, but according to this map [telegeography.com] of submarine communications cables, middle east has more than one cable reaching it.

Re:Not necessarily a single point of failure. (1)

hardburn (141468) | more than 5 years ago | (#26214271)

Given the all the frantic rerouting going on, as well as the similar problems faced earlier this year, we should assume that it is, in fact, a central point of failure, no matter what an abstract overview map tells us.

Re:Not necessarily a single point of failure. (1)

FluffyWithTeeth (890188) | more than 5 years ago | (#26214419)

And most of them are connected to the same city, where one ship can drag its anchor across all of them at once.

The summary has it... (1)

erroneus (253617) | more than 5 years ago | (#26214311)

In the summary is enough information to show who has the most to gain from such an interruption and subsequent re-routing. If they are routing traffic through North America, it will be going through the NSA-snooped network. There are moments when I am not proud of America...

Re:The summary has it... (0)

Anonymous Coward | more than 5 years ago | (#26214859)

You better put your tinfoil hat on just a bit tighter... your thoughts are leaking out and posting themselves on ~/.

Huh? (2, Insightful)

GuloGulo (959533) | more than 5 years ago | (#26215787)

"There are moments when I am not proud of America..."

What does America have to do with you being a paranoid whackjob?

Re:Huh? (1)

erroneus (253617) | more than 5 years ago | (#26215921)

What part of the illegal NSA wire-tapping program did you miss over the course of this entire year?? And just because it has been exposed does not mean it has stopped! It is STILL RUNNING.

cables and eavesdropping (3, Funny)

BigHungryJoe (737554) | more than 5 years ago | (#26214473)

I've got sources inside US intel that tell me these are botched attempts by Syrian intelligence to tap these undersea lines.

The chair is against the wall.

John has a long mustache. That is all.

Any ideas ... (1)

PPH (736903) | more than 5 years ago | (#26214933)

... about who did it?

With OTDRs on-line ready to go on line at ech end of the cable, one should be able to locate the break within hours (if not minutes). Put that together with satellite recon photos and one should be able to track and identify ships in the area to narrow the search down.

Yeah, I know who runs the satellite networks. And it might not be in their best interest to identify one of their own ships. But I'm certain that the Russians would be more than happy to provide the needed data, just to see egg on the NSA's face.

If a sub cut it, it should actually be easier to identify. There are so few nations with this kind of capability and so many people watching them that they should be easy to spot. I'm sure Israel knows where every Syrian, Egyptian, etc. sub is in their end of the Med.

#irc.trooltalk.com (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26215057)

may be hurting the parts. The current WEBSITE. MR. DE I won't bore you

Clever Pirates (0)

Anonymous Coward | more than 5 years ago | (#26215131)

Pirates cut the cables so they can plunder the ships that come to fix them!!

Sounds like fun (1)

mralphabet (809565) | more than 5 years ago | (#26215533)

When doing a cabling job in Anchorage we cut into a data cable that was unmarked on our maps. We had a fun time splicing that, think it was 100+ pair cable. Sitting in a dirt ditch splicing wires is fun.
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