<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">This is such a cool summary of the current process...<div class=""><br class=""></div><div class="">Once I was wasting time in the Dartmouth engineering library (when I was supposed to be doing work). I found an older book about the laying of the first trans-Atlantic cable. They had terrible problems (their first effort failed), for example...</div><div class=""><br class=""></div><div class="">- It was a single strand insulated by gutta-percha (rubber-ish stuff I think). They tested for continuity by hourly (?) tests from a team on shore sending current one way for a minute, then the other way. They used a galvanometer to detect... Talk about low bits/second.</div><div class="">- When the cable broke, they used the same "back up and drag a grappling hook" technique to snag the cable and bring it up</div><div class=""><div class="">- It weighed a ton - literally. If I remember correctly, each length from the sea floor to the surface weighed 6,000 pounds, so they had to hoist 12,000 pounds of cable to begin to find the broken end</div><div class=""><br class=""></div><div class="">Everything's the same... But a lot better :-)</div><div class=""><br class=""></div><div class="">Rich</div><div><br class=""><blockquote type="cite" class=""><div class="">On Feb 18, 2022, at 5:27 AM, Ulrich Speidel <<a href="mailto:ulrich@cs.auckland.ac.nz" class="">ulrich@cs.auckland.ac.nz</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" class="">
<div class=""><p class="">I've heard nothing further about teleport establishment in Fiji,
but that doesn't mean that nothing has happened.</p><p class="">Meanwhile, cable repair has progressed a good bit. The damage was
far greater than originally envisaged. On the international cable,
faults (complete cable ruptures and fibre damage) stretched over
more than 80 km. The cable ran entirely SOUTH of the Hunga Tonga
Hunga Ha'apai volcano (about 60 km away and shielded by a number
of submarine mounts for at least parts of the damaged section).
Yet the Reliance cable ship traced one disconnected cable piece
end to about 5 km NORTH of its nominal route, found various
sections had disappeared completely, and recovered sections of up
to 9 km at a time from the seabed.</p><p class="">A bog standard cable break requires two holding drives (or
drags), HD for short, to pick up each of the cable endpoints from
the seafloor. It also requires either an ROV dive to check if the
cable has completely separated at the fault position, or a cut if
the cable is still held together by the steel. That cut can be
done either by ROV as well, or if visibility doesn't permit ROV
use, by a cutting drive (CD). Any HD or CD requires the cable ship
to tow a seafloor grapnel / cutter device transversally across the
cable, so they're easy to spot on position traces. The Reliance
did no fewer than seven HD's in its eastern operations area near
Tongatapu, where it worked first. Visibility there was good (so
ROV could be used), but damage substantial. <br class="">
</p><p class="">The ship then proceeded to the western end of the fault zone
where reflectometer measurements from the Suva end had found a
fault. Because of bad visibility, they did a CD followed by 2 HD's
there, then noticed that there was fibre damage along the cable to
Suva, so reeled that in and cut the damaged bit out.</p><p class="">They then proceeded to put a "mini-system" together. Let me
explain: Enroute to Tonga, the Reliance stopped at Subcom's depot
in Apia (Samoa) to load whatever cable they had in store there.
This included spares not only for the Fiji-Tonga cable but also
for various other cable systems in the wider region. Reliance left
Apia with about 80 km of cable in total. The amount of cable that
will need to be re-laid along the damaged international section is
90 km (you need to allow for a bit of cable lengthening due to
slack being inserted when cable ends are being brought up from
2000 m (6000 ft) or so below). This means that the Reliance is
re-using some of the cable recovered from the damaged section, and
the whole "mini-system" will be one long stitch job. The damaged
section also included a repeater worth US$230k, which they were
trying to recover and which was still missing as of this morning -
I've yet to hear from my contact as to whether they were
successful on the last recovery attempt today (they've left the
area after three drives and are heading West right now. The rest
of the mini-system was going to be laid after the repeater
recovery attempt (the overall success doesn't depend on the
repeater being found, but the final repair bill does). I thus
expect the cable repair to be completed in the next few days.</p><p class="">The domestic cable is another story altogether, unfortunately.
This has a blind stretch of 77 km at present, as measured by
optical reflectometer from Tongatapu and Ha'apai (there was meant
to be a measurement from Vava'u yesterday but I haven't heard yet
what this revealed, the cable from Tongatapu has two fibre pairs,
one of which heads to each destination from a branching unit west
of Ha'apai. That said, once the international cable has been
fixed, the Reliance won't have enough cable left to complete the
domestic job, even if some cable bits could be recovered there.
The next available stock of suitable cable is in Europe, around
35-40 days one-way shipping away. They intend to bridge this time
gap via satellite (and I'm sure would welcome a Starlink
delegation with a teleport to connect to the international cable,
too, especially now that the Australian Navy gave them Omicron
along with their aid deliveries).</p><p class="">I've been in close contact with our volcanology / geophysics
community here in NZ, who know the area well. The story of damage
to the international cable is now shaping up to be a pretty
complex one. What we know thus far is that it was neither the
volcano's initial blast nor the subsequent tsunami that killed the
cable - the outage began only well after the tsunami had hit. In
all probability, it's been a combination of submarine landslides
and turbidite waves from a variety of sources that hit hours and
possibly many days after the eruption. Finding that a cable piece
has moved 5 km TOWARDS the volcano points at an event south of the
cable route, and the mix of seafloor visibilities encountered by
the Reliance points at there having multiple events from multiple
sources. There have been plenty of quakes upwards of M4 and even
an M6.2 in the wider area that could have triggered slopes,
especially with an extra layer of ash on them. Turbidite waves can
travel up to 1000 km, aren't anywhere near as fast as a tsunami,
and have long been known to have damaged cables in the past (see
B.C. Heezen and M. Ewing, Turbidity currents and submarine slumps,
and the 1929 Grand Banks Earthquake, American Journal of Science,
v. 250, pp 849-873, December 1952. This quake killed 12 submarine
cables over more than 18 hours).<br class="">
</p><p class=""> Meanwhile, there's still limited satellite service in and out of
Tonga, but I can confirm that e-mails (even with attachments) make
it in and out OK.</p><p class=""><br class="">
</p>
<div class="moz-cite-prefix">On 18/02/2022 8:27 pm, Mike Puchol
wrote:<br class="">
</div>
<blockquote type="cite" cite="mid:866041e1-efaf-43f1-b218-6a6d73f6496f@Spark" class="">
<title class=""></title>
<div name="messageBodySection" class="">
<div dir="auto" class="">Hi Daniel,<br class="">
<br class="">
I added it after there was a confirmation on Twitter that
SpaceX people were on the ground to set one up, and also, as
two /27 blocks (IPv4) have been assigned to Fiji’s capital,
under the Sydney POP, and they can be pinged.<br class="">
<br class="">
Wether it’s at the teleport or not, unsure, but for
simulation, an error of even a few km doesn’t really matter.</div>
</div>
<div name="messageSignatureSection" class=""><br class="">
<div class="matchFont">Best,<br class="">
<br class="">
Mike</div>
</div>
<div name="messageReplySection" class="">On Feb 18, 2022, 06:04 +0100,
Daniel AJ Sokolov <a class="moz-txt-link-rfc2396E" href="mailto:daniel@falco.ca"><daniel@falco.ca></a>, wrote:<br class="">
<blockquote type="cite" style="border-left-color: grey;
border-left-width: thin; border-left-style: solid; margin: 5px
5px;padding-left: 10px;" class="">On 2022-02-07 at 15:29, Mike Puchol
wrote:<br class="">
<blockquote type="cite" class="">As far as placing a gateway in Fiji,
it already has a teleport<br class="">
facility, which will have power and fibre (unless that one
has been<br class="">
taken out too?). <a href="checkhttps://goo.gl/maps/6BYXf4R17yys7zNe9" moz-do-not-send="true" class="">Checkhttps://goo.gl/maps/6BYXf4R17yys7zNe9</a><br class="">
</blockquote>
<br class="">
Hey Mike, you put a "SUVA (Emergency)" ground station on
starlink.sx.<br class="">
<br class="">
Is that for simulation, or has Starlink actually installed a
ground<br class="">
station in Fidschi by now? Would you have positive
confirmation?<br class="">
<br class="">
Thank you<br class="">
Daniel<br class="">
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<pre class="moz-signature" cols="72">--
****************************************************************
Dr. Ulrich Speidel
School of Computer Science
Room 303S.594 (City Campus)
The University of Auckland
<a class="moz-txt-link-abbreviated" href="mailto:u.speidel@auckland.ac.nz">u.speidel@auckland.ac.nz</a>
<a class="moz-txt-link-freetext" href="http://www.cs.auckland.ac.nz/~ulrich/">http://www.cs.auckland.ac.nz/~ulrich/</a>
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