[HN Gopher] The British empire's resilient subsea telegraph network
___________________________________________________________________
The British empire's resilient subsea telegraph network
Author : giuliomagnifico
Score : 149 points
Date : 2025-12-30 13:10 UTC (9 hours ago)
(HTM) web link (subseacables.blogspot.com)
(TXT) w3m dump (subseacables.blogspot.com)
| jphoward wrote:
| Here is some more information:
| https://en.wikipedia.org/wiki/All_Red_Line
|
| And one of the old cable huts still exists:
| https://en.wikipedia.org/wiki/Pacific_Cable_Station
| alexfoo wrote:
| Anyone visiting the South West of the UK should go visit
| https://en.wikipedia.org/wiki/PK_Porthcurno
| (https://pkporthcurno.com/)
|
| (There's also the https://en.wikipedia.org/wiki/Minack_Theatre
| built into the cliff face nearby.)
|
| (I've been to the theatre a number of times but never convinced
| my in-laws to visit the Telegraph Museum.)
| kitd wrote:
| My wife and I were visiting County Kerry in SW Ireland last
| summer. We were on Valentia Island and quite by chance walked
| past the telegraph building where the first transatlantic cable
| came ashore. Only marked by a (very interesting) plaque
| describing its significance.
| thomasbibby wrote:
| There is also a small museum at the site, worth a look if you
| visit again! https://valentiaisland.ie/cable-station/
| neillyons wrote:
| When visiting Ayers Rock in Australia I stayed in Alice Springs.
| While I was there I learnt that Alice Springs exists because it
| was a repeater station for a telegraph line that stretched from
| Southern Australia all the way to London. There would be people
| listening to morse code, and tapping it out again to the next
| repeater station. Blew my mind that there was a wire that went
| all the way to London from Australia!
| dboreham wrote:
| Similar history for Denver.
| alexfoo wrote:
| > Blew my mind that there was a wire that went all the way to
| London from Australia!
|
| Before the telegraph they used to do things wirelessly:
| https://www.brunningandprice.co.uk/_downloads/telegraph/tele...
|
| (Not quite London to Australia though...)
|
| In the late-1700s/early-1800s the Admiralty Telegraph was used
| to relay messages between London and Portsmouth (70 odd miles
| apart) using a semaphore type system with repeater stations
| every 10 miles or so.
| Aromasin wrote:
| To think it was done even 1000s of years prior to that with
| just smoke and fire! Granted, the ability to communicate
| through the rain would be a necessity for the British.
| vintagedave wrote:
| In Tasmania, you can still see at least one semaphore station
| on Mt Nelson, which is above several suburbs on the south of
| the city of Hobart. I believe there was a semaphore route
| from the capital to Port Arthur (convict prison) and possibly
| other routes over the state too.
|
| https://www.utas.edu.au/library/companion_to_tasmanian_histo.
| ..
|
| Sadly the semaphore pole itself is gone. The building is
| still there and was used until 1969.
| kitd wrote:
| Yes, the Uk (southern England in particular) is dotted with
| "Semaphore Hill"s or "Telegraph Hills"s. There's one very
| close to where I'm sitting now, a few miles NE of Portsmouth.
| teleforce wrote:
| Fun facts, the subsea telegraph network cables coating were made
| from Gutta Percha [1].
|
| Unlike normal rubber, it is a type of thermoplastic and it's a
| popular organic plastic before the petroleum based modern plastic
| become pervasive [2].
|
| [1] The legacy of undersea cables:
|
| https://blog.sciencemuseumgroup.org.uk/the-legacy-of-underse...
|
| [2] Gutta-percha:
|
| https://en.wikipedia.org/wiki/Gutta-percha
| daedrdev wrote:
| They also got a tiny fraction of the rubber from cutting a
| whole tree down due to not finding a method to get all the
| rubber, and so cut almost all of the trees down
| andyjohnson0 wrote:
| An interesting book on the subject of telegraph networks is _The
| Victorian Internet_ by Tom Standage [1]. As well as the technical
| and commercial drivers, it also describes how the telegraph
| forced people to confront concepts like simultaneity, information
| being distinct from its physical medium, privacy, early
| approaches to encryption, etc. A fascinating book.
|
| [1] https://en.wikipedia.org/wiki/The_Victorian_Internet
| kogasa240p wrote:
| Oh wow will definitely give that book a read, very interesting.
| eszed wrote:
| I've recommended that book on this board before. If you read
| it, I'd be curious about how you think it hits now, because
| part of its interest - I'd say insightfulness, at the time,
| but it now might risk anachronistic "charm" - was noting
| similar emergent behaviors between telegraph operators and
| early internet adopters. The technical content won't have
| dated, but the social parts may have.
| jgalt212 wrote:
| I came here to recommend this fine book as well.
| retrac wrote:
| The GBP/USD currency pair is still known just as "the cable".
|
| Aside from all its other uses: the telegraph gave a way to
| synchronize clocks. And accurate time is accurate measurement
| of distance.
|
| > [...] The latest determination in 1892 is due to the
| cooperation of the McGill College Observatory at Montreal,
| Canada, with the Greenwich Observatory. [...] The final value
| for the longitude of the Harvard Observatory at Cambridge, as
| adjusted in June, 1897, is 4h 44m 31s.046 +-0s.048.
|
| -- https://adsabs.harvard.edu/full/1897AJ.....18...25S
|
| 71.12936 W; give or take about 2 metres:
| https://www.bing.com/maps/?v=2&cp=42.38148%7E-71.12936&style...
| tor825gl wrote:
| One of the major uses for the telegraph was the first funds
| transfers that could happen quicker than moving paper (or
| bullion) from one location to another. London banks would
| telegraph correspondent banks in India, Australia, etc.
|
| This essentially doubled the capital intensity of
| international trade since the goods had to move in one
| direction but the money could be sent instantaneously in the
| other.
| zoeysmithe wrote:
| That book led me to Gutta Percha, the plastic-like coating on
| the wires used in these cables which was quite the innovation
| and made this all possible. Vulcanized rubber was the other
| option but performed poorly in cables and was harder to work
| with.
|
| https://atlantic-cable.com/Article/GuttaPercha/
|
| The above is a fascinating and depressing history of the Gutta
| Percha factory that made all these cables, after joining with
| the cable company that supplied the actual wires. There's an
| 1853 travelogue piece embedded here of an author visiting the
| factory, where he notes in the worst parts of the factory where
| boiling and heat are applied, it was staffed with boys who
| barely made more than a dollar a week. By boys I thought it was
| slang for young men then I realized 1850s England was heavily
| using child labor.
|
| Those cables are the product of child labor, like much of the
| Victorian age's industrial and textile output. Children often
| made up significant portions of factory workforces, sometimes
| 25-50% in certain textile sectors, with many under 14. I wish
| the stories of child labor were better told and more prominent.
| This abuse and exploitation of children gets quite whitewashed
| during this age and its nice to see it acknowledged, albeit
| briefly.
| ninalanyon wrote:
| At least in the UK the fact that the Victorians and others
| used a lot of child labour is well and widely known.
|
| Blake wrote the poem The Chimney Sweeper about boys sold into
| the trade long before the 1850s and Elizabeth Barrett
| Browning published The Cry of the Children in Blackwood's
| magazine in 1843. Charles Kingsley used his The Water Babies
| to question child labour and England's treatment of the poor
| in general in 1862-3.
|
| No one with any pretensions to knowledge of those times can
| claim not to know about child labour.
| zoeysmithe wrote:
| I imagine the percent of people who know these telegram
| cables were made by children is a very low percentage.
| petesergeant wrote:
| Is the latency the same now as it was for the signal itself?
| Obviously the throughput is rather different.
| hylaride wrote:
| Over long distances, fibre optic would have lower latency so
| it'd be shorter if taking the same path today. But these
| signals would likely have been morse code and sent one-way at a
| time, so latency wouldn't have been noticed unless the
| repeaters were people rebroadcasting the signal (no idea how
| that was done).
| joecool1029 wrote:
| > Over long distances, fibre optic would have lower latency
| so it'd be shorter if taking the same path today.
|
| Source that claim, it's well understood the speed of light is
| around 66% due to refractive index in glass.
|
| It gets weird with telegraph cables and capacitance,
| wikipedia at least touches on it here:
| https://en.wikipedia.org/wiki/Speed_of_electricity
| hylaride wrote:
| I should have definitely qualified that statement.
| Technically, electrical signals over copper are "slowed
| down" less than light through fibre optic cables. However
| there's attenuation, electromagnetic interference, and
| other signal loss for electrical signals that (for long
| haul cables) will mean you will need repeaters that add
| significant amounts of latency. On top of that, the higher
| you try and up the frequencies, the worse these problems
| get.
|
| For some medium-haul stuff, it wouldn't surprise me if you
| saw copper still being used for lower latency (eg between
| datacenter sites for flash-trading), but otherwise it's
| just not economical.
| everfrustrated wrote:
| That's the point of hollow-core fibre which is absolutely
| being used where decreasing latency even by small amounts
| is worth it.
| joecool1029 wrote:
| > That's the point of hollow-core fibre
|
| Ok, how does that work though? I understand the concept
| of lower attenuation since air/vacuum has less molecules
| to get in the way. Less repeaters, should have less
| system latency.
|
| What I don't understand is how light is moving through
| what is a hollow bendable medium. Is the tube that it's
| in reflective and there's just less time it's passing
| through it? I guess that's the main one in commercial use
| to shave some time off, reading about it here:
| https://en.wikipedia.org/wiki/Photonic-crystal_fiber
| everfrustrated wrote:
| It works in that light will travel faster in a less dense
| medium. Remove the relatively denser glass for
| gas/vacuum.
|
| Also the way fibre works is commonly misunderstood. The
| light isn't bouncing.
| tor825gl wrote:
| My understanding was that the latency was much higher due to
| manual repeating at stations along the way.
|
| Eg. when the London-Mumbai telegraph was new it took around 45
| minutes in one direction.
| Alive-in-2025 wrote:
| I love stories like this! Neil Stephenson has a great wired
| magazine article about information technology of that time, and
| telegraphs. The article is kind of a precursor to the ideas in
| his excellent book cryptonomicon. You should stop what you are
| doing and read that wired article. And then cryptonomicon if you
| haven't already done it. Best book to read over the rest of our
| holidays.
|
| Article in paywall at https://www.wired.com/1996/12/ffglass/
|
| The book and the article are fascinating explorations of the
| impact of technology and cryptography on the world. The people
| who did the work to invent and build these worldwide systems were
| just like us (hackers, inventors, technologists), and we are just
| like them in a way. We all stand on the shoulders of giants.
|
| Also I can't believe that article is 30 years old, boy I'm old.
| pchristensen wrote:
| I always have to recommend Mother Earth, Mother Board by Neal
| Stephenson[1] if the thought of undersea cables sounds at all
| interesting. I'll also second andyjohnson0's recommendation of
| The Victorian Internet[2] - it blew my mind how much of modern
| digital culture existed on telegraphs prior to voice.
|
| [1] https://www.wired.com/1996/12/ffglass/
|
| [2] https://news.ycombinator.com/item?id=46433901
| thijson wrote:
| Seeing the telegraph cross Canada like that reminded me of the
| network of hotels across Canada that were used by the wealthy on
| their way to the Orient from Europe during a bygone era.
| nephihaha wrote:
| The original internet, more or less. Apparently whales liked to
| scratch themselves on some of the cables though.
| jimmySixDOF wrote:
| ... an era bookmarked at the end by the first live music
| broadcast transatlantic performance of Old Man River from a
| studio in NYC to a theater in London and that wasn't until 1957
| and is a story all on its own
|
| https://www.sciencemuseum.org.uk/objects-and-stories/robeson...
| KineticLensman wrote:
| It was strategically important in WW1 because the British could
| communicate with the colonies with very chance little chance of
| messages being intercepted. The Germans, in contrast, didn't have
| access to their own transatlantic channels and had to use plain-
| text messages on cables that the UK/US controlled (US operators
| disallowed coded comms).
| mjlee wrote:
| If you enjoy this, you might like to read about the Zimmermann
| Telegram - British SIGINT that took advantage of this network,
| bringing the USA in to World War I.
|
| https://en.wikipedia.org/wiki/Zimmermann_telegram
| alexjf12 wrote:
| here's an interesting series of videos on undersea cables, as
| described by... Tool Time from Home Improvement
|
| https://youtu.be/zmyBSrQodnI?si=OpFZhiQeNn3ax58p
| utopiah wrote:
| The Cable that Changed the World (2024) is pretty nice on the
| topic. Shows us how, again, most of the things we consider "new"
| or at even revolutionary most showcase how historical ignorance.
| hakkikonu wrote:
| in this context: https://www.submarinecablemap.com/
___________________________________________________________________
(page generated 2025-12-30 23:00 UTC)