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Undersea Cable Repair Via 19th Century Tech
An anonymous reader writes to mention a story going across the wires about an old-fashioned way to fix a modern convenience. Taiwanese boaters are using simple hooks to fish up the fiber-optic cables damaged in an earthquake late last year. The outage that resulted kept millions of users offline in half a dozen countries around the Pacific rim. From the article: "They work 24 hours a day but the weather can hinder their progress. Walters said one ship is waiting for 30 to 40 mile-an-hour winds (48 to 64 kilometres- an-hour) to die down in the Bashi Channel. The winds have stirred up 10 to 12 metre waves ... After arriving at the scene they survey the ocean bottom to assess whether the contour has changed, and the degree of sediment movement. Then the traditional tools are brought out. A rope with a grapnel on the end is played out, down into the depths, and towed over the sea floor until tension registers on a graph on the ship, indicating contact has been made with the cable. Today's fibre optic cables are just 21 millimetres in diameter."
Correct me if I'm wrong, I'm no expert on this subject, but undersea cables certainly aren't 21 mm wide. Certainly they are run in bundles of dozens (maybe hundreds) for a total width of several inches. At work we had fiber cable installed that has 16 or so strands and it was half an inch thick.
:)
I guess it's just bad writing and I shouldn't be so nitpicky.
Anyway, with all this wind and water moving, how do they find a 21mm cable 2.5 miles down? A rope that far would bend under air resistance, let alone water resistance. I think some high technology went into this somewhere. Kudos on not making it too complicated. KISS at work.
"Build a man a fire warm him for a day, set a man on fire and warm him for the rest of his life."
http://www.google.com/search?q=21+millimetres+in+r ods
They can find a cable using just a rope and a hook. And shipwreck hunters with modern equipment have a hard time finding ships when they know where they went down.
Libertarian Leaning Political Discussion Forum.
What, are they Amish or something? Every modern company uses sharks with friggin' lasers to repair optical cables.
... and then they built the supercollider.
I beg to differ. There are devices known as OTDRs (optical time-domain reflectometers). Essentially, you shoot a pulse of light down the carrier and start a high-speed counter. The difference in refraction (say, a break in the cable or the end of the cable) causes a reflection that is detected at the device. Using the elapsed time, you get the distance to the break.
r eflectometer
Check out this link http://en.wikipedia.org/wiki/Optical_time_domain_
I also saw a documentary on the Science channel about these ships. The whole process of fixing the break is sterile and professional. They use fusion splicers, which fuse the two ends with an electric arc. Fascinating stuff.
-- Posted from my parent's basement
I thought modern browser technology was supposed to prevent fishing?!?!
David 'Volk' Mc. Itazura!
Yes, your nearest school. Give it a try.
Where can I get the jeff shell? And how does it differ from bash/korn?
(thanks for your link with the rods information too)
There are shills on slashdot. Apparently, I'm one of them.
Actually, it didn't keep people offline in Asia. It just made international Internet connections incredibly slow. Using the Internet for national sites, which is the vast majority of Internet use, was barely effected. Here in China, nobody at my American-owned computer company even cared, except that MSN chat was pretty spotty for a couple days.
Slashdot: providing anti-social weirdos a soapbox, since 1997.
Very charming are the noble savages who use such primitive technology to repair these so-called Optikal-Phybers. Who can imagine what these presumably sacred artifacts mean to these tribesmen?
Just like to point out.. You are the one that uses "wierd E and R switched" metric.. We southern hemisphere people tend to use normal "re". You should try it sometime. Centre, Litre, Metre.. the list goes on..
21 millimeters to inches
Thats it!? I would have imagined somthing larger.
10 meters to feet
Cowabunga Dude! (hey that reminds me, someone is making a new TMNT flick)
Disclaimer: Yeah, yeah, i know the rest of the free world uses metric, so save your self some typing by not replying to let me know i'm an asshat. yeah, you know who you are... limey bastard
uses 19th century tech, boats are way older than that. a head line missed
Windows is a bonfire, Linux is the sun. Linux only looks smaller if you lack perspective.
And weird E and R switched in meter metric!
Meter == device for measuring stuff. I.e. volt meter, etc.
Metre == measure of distance (the distance travelled by light in absolute vacuum in 1/299,792,458 of a second.)
Just because Americans can't spell doesn't mean the rest of the world has to adopt your broken spelling.
http://blog.nexusuk.org
No pics no digg! :-P
Measuring with your thumbs and feet, that's just so barbaric!
When a method works well, there is not really a need for something else, it will only be used when it is superior. So what would those alternatives be, that are cheaper overall?
A submarine robot repairing on site is probably not possible (I have problems believing it would be able to fuse the fibers), so you only could use it to more quickly find the cable and perhaps make it easier to get the hook onto it as you can see what you are doing. But honestly, how much faster would it be, I guess a hook and the cable for it can just be tossed into the water, an expensive robot probably would take a bit longer to reach the ground. And it probably has limitations on the depth it can operate. Additionally I am quite sure they don't just drive out there and plow the sea bed, they probably have a very good idea where the cable is supposed to be. And don't forget, to find a very long cable is much simpler than finding a wreck. I don't have to find a particular piece, any piece before and after the break is ok, as I can just pull the part up and then follow it, no need to exactly grab the end.
Also the strong winds and high waves probably would make fusing the cables very hard as well, even if they could bring up the cable. So the only thing 'old fashioned' I can see is, that they use a hook. The rest is probably quite up to date and the hook is simply the easiest, most reliable and cheapest way. Why use expensive technology if something simple is perfectly adequate?
I don't want to seem overly flippant, but is there really something significant about mariners using hooks to pull stuff out of the sea? I'm not really clear what the alternatives were. I'm expecting "Man Digs Hole With Spade" and "Tech Professional Presses Distant Button With Pointed Stick" as future headlines. OK. I admit that was overly flippant.
Note that it is only in English that the measure of distance is spelt "metre". Other languages (e.g. German, French) use "meter" for it (Italian and Spanish use "metro" for both). I have no idea why this letter switch happened in English.
"Little does he know, but there is no 'I' in 'Idiot'!"
Note that it is only in English that the measure of distance is spelt "metre". Other languages (e.g. German, French) use "meter" for it (Italian and Spanish use "metro" for both). I have no idea why this letter switch happened in English.
This is untrue - the French use "mètre"
http://blog.nexusuk.org
Note that it is only in English that the measure of distance is spelt "metre". Other languages (e.g. German, French) use "meter"
In french, you write "mètre", and if you're an english native speaker, there's a high probability you just can't pronounce it right.
Another, related thing:
I don't know how americans mesure winds, but here in Sweden we always mesure them in m/s, and nothing else.
48 to 64 kilometres-an-hour would then be 13 to 18 m/s
And that doesn't seem to be very much, now(saturday morning) the winds at the coast where I live are 18-22 m/s, and it isn't even very much.
So then we can assume that:
Theater == facility for viewing movies, plays, symphonies, etc.
Theatre == the drama and spectacle on display in a theater
Pepper == a spice
Peppre == the hot sensation you get by eating pepper
Jester == comedic performer in medieval times
Jestre == the jokes and skits he performs
Adapter == Device which connects two things which otherwise wouldn't
Adaptre == The quality of the connection being changed (e.g. gender, voltage, diameter, etc.)
Diameter == Device for measuring diametre
Diametre == Distance across something round
Hm, wait a sec...
"A great democracy must be progressive or it will soon cease to be a great democracy." --Theodore Roosevelt
The french word is in fact "(le) mètre", not "meter". If there was a word like 'meter' in French I think it would be pronounced meu-teh and be considered a verb.
So... my guess is that the English imported the word along with the unit from the French.
Superglue? Hairpins? Teleporters? IT'S AN UNDERSEA CABLE. Sheesh...
:) (Sorry, couldn't help it)
And yes, BTW: No one exects the Spanish Inquisition!
--- For a good time mail uce@ftc.gov
You mean undersea fibre links are just cables laying on the sea floor?! I don't know what I expected, but somehow I'm disappointed.
Yesterday was the time to do it right. Are we having a REVOLUTION yet?
21 millimeters = 0.00417561441 rods
My father worked in the cable industry in the 1950s and 1960s. He tells an interesting story from the start of the second world war.
Immediately after Britain declared war in 1939, a cable ship was sent out into the North Sea to dredge up the German cables, which ran from Hamburg through the North Sea and out into the Atlantic. They found the cables using a hook, exactly as described in this story, and cut through them.
Of course it would be easy for the Germans to go out with their cable ship, dredge up the two ends, and join them back together again - if they knew where to look for the break. And it's not hard to find out how far along the cable the cut is, as a pulse will be reflected from the break. This had been well understood for a hundred years.
Knowing this, the British engineers made some sort of contraption full of capacitors and coils that they could fix on to the end of the severed cable before dropping it back into the sea. This would add some extra delay to the reflection, causing the Germans to miscalculate where the break was, and send their cable ship to the wrong place.
the link quote by parent poster:h tml?pg=2&topic=(none)
/methinks.
... 207 Million seems to be jump change for a network like that; ... err that other american
http://www.wired.com/wired/archive//4.12/ffglass.
FLAG (www.flagtelecom.com), a 50'000 km fiber network was bought by a Indian company
(http://www.rediff.com/money/2003/oct/16ril1.htm) for about 207 million dollars. weee...
latest news is that they are trying to list them at the
london stock exchange for 500 million dollars.
as a previous poser said that good engineering stays invisible,
well, it might not be so good in the long run.
maybe we should all chip in for a garuntee future of the GLOBAL internet.
there's a big difference between owning stock in say at&t,
sprint and a undersea network
on a side note, i think it's amazing that FLAG was able to go bankrupt
anyway
just to compare it to AT&T 50 BILLION bid for
network >>>:P (
(bell south would have to be 241 times bigger then FLAG)
But you should have the cable that got away!!
Ive always wondered how, or if, they repair cables which are located several miles underwater and continue for a thousand miles. How would you ever hook onto such a cable, and pulling it to the surface seems rather difficult to me and would put a lot of stress on the cable. I just assumed if the cable went bad, they would have to lay all new cable.
Uh, undersea cables ARE 19th century tech.
160 acres is 80 square rods.
One metre is 39 inches.
One inch is 2.54 centimetres.
One foot is 12 inches.
three feet is one yard.
"Free software" is a matter of liberty, not price.
I've lost track of the number of pre-20th-century inventions I've used just this week.
Pencil, all-natural-fiber clothing, unprocessed foods, the light bulb, and many other things.
If it works, use it.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
30 to 40 mile-an-hour winds, 10 to 12 metre waves, undersea cables that always break. Isn't there some other country they could be writing software in that doesn't have all these problems?
one from Walmart, at least here in the US. :-)
"Not an actor, but he plays one on TV."
A rod is 1/40th of a furlong
my question is why do all the cable systems seems to pass the same path? some would say that the path is the "safest." look what happened now. it's not as safe as they think.
most providers are boasting of diversified systems but at the end, all their cables pass through the same area. if only i have enough money to establish my own telecom company.
a rant (a little off topic) - i'm from the philippines and my isp, then connected to a carrier, globe telecoms has not yet been able to recover much after all the weeks. they seem to rely on just one cable system (c2c.) it took them around two weeks at least to add additional capacity from other networks. i'm also angry at them as they block certain bandwidth intensive sites like youtube. as a carrier, they should not block sites (the slowness in speed would have deterred many from accessing the site anyway.) at the same time, they are not very good in balancing traffic. some of the sites that pass on certain upstream providers are fast and some are very slow to a point of not being able to visit because they pass through congested links. if only i could call them and tell them what to do.
Live your life each day as if it was your last.
This kind of story shows us that we need as much redundancy and as many different technologies to communicate as possible. All of them can be used by the internet, so the chances of getting cut off will keep getting reduced. And I really believe getting access to the internet and with it an astounding amount of information out into as many parts of the world as possible is essential. Hopefully the next OLPC will have some long distance wireless tech.
I read a book from 1896, Wilkinson's Submarine Cable Laying and Repairing. I was pretty impressed with the complicated grapnels they had back then--capable of scooping up a delicate cable, slicing the cable as appropriate. I was so impressed that I typed up the grapnel chapter, scanning in the illustrations: http://lahosken.san-francisco.ca.us/frivolity/wilk inson/I_3.html
It would be pronounced meu-tay, and would not necessarily be a verb.
Stupidity is like nuclear power, it can be used for good or evil. And you don't want to get any on you.
I've always wondered about underseas cables (and haven't really found an answer)... they lay on the bottom, so what happens when you come to an underseas trench? Surely they don't go down the cliff to the bottom of a 20-000 foot trench.... but does that mean they suspend it across? Or do they go hundreds of KM out of their way to avoid trenches altogether?
If I knew the wedgies I gave you back in 6th grade would have resulted in this . . . I might have taken a moments pause.
Partially right - throw it out, take a tax write-off, put up some PR about how the cable isn't really broken and the customers must have something wrong on their end, then a few months later replace it and acknowledge that there were some software errors that are now fixed.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)