Speaker 1: Welcome to tech Stuff, a production from I Heart Radio.
Speaker 1: Hey there, and welcome to tech Stuff. I'm your host,
Speaker 1: Jonathan Strickland. I'm an executive producer with iHeart Radio and
Speaker 1: I love all things tech and longtime listener and Tricks
Speaker 1: wrote in on Twitter to ask if I had done
Speaker 1: an episode on undersea cables, and you know what, I haven't.
Speaker 1: So today we're going to start to talk about them, because,
Speaker 1: as it turns out, there's a lot to cover with
Speaker 1: undersea cables to kind of understand not just how they work,
Speaker 1: but the challenges that people faced in order to make
Speaker 1: them a reality in the first place. This is also
Speaker 1: a timely topic because recently a company called x Links
Speaker 1: made headlines for the Morocco UK power plant project. That
Speaker 1: project's goal is to create a bowler and wind farm
Speaker 1: in Morocco and use a very very long sub sea
Speaker 1: power chord, essentially to send electricity to the UK. Now,
Speaker 1: while a lot of headlines called this the longest subseed cable,
Speaker 1: that's misleading because there are actually many different types of cables,
Speaker 1: and technically the ce ME WE three cable that's s
Speaker 1: E A dash M E dash W E three, the
Speaker 1: number three cable is actually about ten times longer than
Speaker 1: what the Morocco UK cable will be. But we're gonna
Speaker 1: get to all that probably in the next episode, definitely
Speaker 1: not this one. But as and Tricks pointed out in
Speaker 1: a tweet to me, undersea cables trace their history back
Speaker 1: to the mid nineteenth century. So in order to understand
Speaker 1: all of this, we really have to take a moment
Speaker 1: and talk about the telegraph and the development of the
Speaker 1: first undersea cables. So there were a few things that
Speaker 1: had to happen for undersea cables to even become a necessity.
Speaker 1: You know. One of those was the development of the
Speaker 1: electric telegraph, because without that, there's no need to worry
Speaker 1: about subsea cables. Right, If you don't have long distance
Speaker 1: electric based communication, then cables aren't really a thing you
Speaker 1: gotta worry about, at least as far as connecting, say
Speaker 1: an island to a continent. Now, the word telegraph is
Speaker 1: Greek and it means essentially distant writing. But this word
Speaker 1: actually predates electric telegraphs. For example, there were semaphore systems,
Speaker 1: ones that used visual cues with flags. Those were used
Speaker 1: throughout France, and we're really developed during the Napoleonic wars,
Speaker 1: and that was referred to as telegraph. Before any kind
Speaker 1: of electric version came along in the late seventeen hundreds,
Speaker 1: you had various smarty pants around the world experimenting with electricity,
Speaker 1: you know, like Ben Franklin, and this was just something
Speaker 1: that was just beginning to be understood at the time.
Speaker 1: Alissandre of Volta had created a sort of proto battery
Speaker 1: that we later called a voltaic pile or and then
Speaker 1: later on we had the voltaic cells. These inventions could
Speaker 1: produce a good electric current, but at a very low voltage.
Speaker 1: Now we need a reminder here because we're gonna be
Speaker 1: talking about electricity a lot. Voltage in electricity is sort
Speaker 1: of similar to water pressure in a plumbing system. You
Speaker 1: can think of it as how much oomph a current has,
Speaker 1: and current you can think of as the amount of
Speaker 1: electricity present in a system of flowing electricity or flowing electrons. So,
Speaker 1: if we want a really quick analogy, if you had
Speaker 1: a low voltage, high current source of electricity, that's kind
Speaker 1: of like a lazy river, right. The river can be
Speaker 1: really wide and it might be really deep, so you've
Speaker 1: got a lot of water there, but that water isn't
Speaker 1: moving very quickly. It's just lazily going down. A high voltage,
Speaker 1: low current electric device produces a very tight, high pressured stream.
Speaker 1: So think of like a a concentrated stream of water
Speaker 1: coming out of a pressure hose. You don't it's not
Speaker 1: nearly the same amount of water as the lazy river.
Speaker 1: It's much less current in other words, but the pressure
Speaker 1: or voltage is way higher. Well before Volta's discovery, scientists
Speaker 1: and engineers were mostly reliant on devices that would build
Speaker 1: up electrostatic charges. So electro static charges have a high
Speaker 1: voltage but a low current, and they have limited applicability
Speaker 1: in things where you need sustained electric current. So Volta's
Speaker 1: invention would allow for new applications of electricity. Now in
Speaker 1: the early eighteen hundreds you had some other smarty pants
Speaker 1: like Hans Christian Orstead of Denmark. And by the way,
Speaker 1: as always, my apologies for all the mispronunciation, and I'm
Speaker 1: going to do of all the different names that is
Speaker 1: on me and I apologize. However, he discovered that electricity
Speaker 1: and magnetism have a connection. He observed that a magnetic
Speaker 1: needle would deflect from magnetic north if it came close
Speaker 1: to a wire that was carrying an electric current or
Speaker 1: transmitting an electric current, and so we first began to
Speaker 1: realize that electro magnetism is a thing, that there is
Speaker 1: this relationship between electricity and magnetism. This would lead to
Speaker 1: yet more smarty pants people thinking of ways that we
Speaker 1: could use electricity through wires to communicate across vast distances.
Speaker 1: One way, a way that Sir William Father gil Cook
Speaker 1: and Sir Charles Wheatston suggested was to have a multi
Speaker 1: wire system that would use up to five needles. They
Speaker 1: experiment with different ones, but the one that they would
Speaker 1: use heavily would have five needle pointers, and that would
Speaker 1: be at the receiving end of this system. So you
Speaker 1: could send different electrical signals down these different wires and
Speaker 1: thus direct these needles these pointers to point to different
Speaker 1: letters on a placard that would have the alphabet there.
Speaker 1: Uh The system would remain in use in the UK
Speaker 1: up through the early twentieth century, so the UK was
Speaker 1: reliant on this system, whereas the rest of the world
Speaker 1: would move on to other ones. The neat thing about
Speaker 1: the system is that it arranged the alphabet in a
Speaker 1: diamond pattern, so it only used twenty letters of the alphabet.
Speaker 1: It left out the letters C, J, Q, U, X,
Speaker 1: and z, so sometimes you had to do, you know,
Speaker 1: approximations of certain words. And the letter A was at
Speaker 1: the top point of the diamond, and then you know,
Speaker 1: you had B and D at the next level, and
Speaker 1: then so on and so forth, and then at the
Speaker 1: bottom you had the letter Y. And the five needles
Speaker 1: were split right in the middle of this diamond. They
Speaker 1: were in the widest part of the diamond, pointing up
Speaker 1: and down normally, which meant that they weren't pointing at
Speaker 1: any specific letter. So by sending signals down specific wires,
Speaker 1: you could make needles point to a specific letter. You
Speaker 1: would have both of you know, two needles that were
Speaker 1: on a diagonal line with a specific letter, and by
Speaker 1: looking at the common letter that both needles were pointing at,
Speaker 1: you could spell out words. An interesting approach, not necessarily
Speaker 1: the fastest, but it worked. Later on, Wheatstone would create
Speaker 1: a different system that had a circular dial uh than
Speaker 1: a needle on the inside, and you had the alphabet
Speaker 1: laid out along the inside circumference of the circle, so
Speaker 1: sort of like an analog clock, except instead of numbers
Speaker 1: for the time, you had the alphabet, and you also
Speaker 1: could have numbers as well. Then you had keys that
Speaker 1: matched the letters and numbers that were along the outside
Speaker 1: of the style. So pressing down on a key would indicate, Okay,
Speaker 1: I want to send this letter UM, and this is
Speaker 1: the sending station, And then you would have a receiving
Speaker 1: station on the other end that would have a similar
Speaker 1: dial with a needle and the letters and numbers in it,
Speaker 1: and pressing down a specific key would end up sending
Speaker 1: a signal that would have the needle on the other
Speaker 1: side point to the relevant letter or number. This way
Speaker 1: was really neat and the way it worked is super cool.
Speaker 1: But I'm gonna have to save that for another episode
Speaker 1: because I'm supposed to focus on subsei cables, and I
Speaker 1: wrote about a page and a half of stuff before
Speaker 1: I realized I am getting way off track, so I'll
Speaker 1: spare you for now, but that will come up maybe
Speaker 1: in a future episode. Now, in America, it was Samuel Morse,
Speaker 1: who interestingly was an art professor who came up with
Speaker 1: the famous method for transmitting messages electrically using a special code,
Speaker 1: one that today, of course, we refer to as the
Speaker 1: Samuel Code. Don't wait no, I'm sorry. No. Morse code.
Speaker 1: Morse code. Morse code uses dots and dashes to rep
Speaker 1: letters and numbers, and by tapping the dots and dashes
Speaker 1: on a telegraph key, you could send pulses of electrical
Speaker 1: signal down a wire, and a receiver at the other
Speaker 1: end could then emboss dots and dashes on a strip
Speaker 1: of paper, so you could actually read out the dots
Speaker 1: and dashes and translate it that way, or later on
Speaker 1: you had engineers who are trained to listen for dots
Speaker 1: and dashes, and you had a device that was essentially
Speaker 1: tapping like a little anvil, tapping out the messages, and
Speaker 1: you would just listen. Later, a guy named Alfred Vale
Speaker 1: would partner with Morse to refine this system and make
Speaker 1: it a little more practical, essentially looking at the most
Speaker 1: frequently used letters and using the the simplest dots and
Speaker 1: dash patterns to represent those letters, as well as to
Speaker 1: redesign the telegraph key itself. By eighteen thirty seven, Veil
Speaker 1: and Morse were demonstrating this technology, and by eighteen forty
Speaker 1: three they secured funding to set up an experiment telegraph
Speaker 1: line that stretched the thirty five miles around sixty kilometers
Speaker 1: between Baltimore, Maryland and Washington, d c Here in America.
Speaker 1: The project used poles that were erected alongside a railroad
Speaker 1: line and wires connected to the poles via glass insulators,
Speaker 1: and it worked. One thing that really amazed me as
Speaker 1: I was doing research into this, just as a quick digression,
Speaker 1: is how quickly things moved. Because this was eight three,
Speaker 1: and we're gonna be talking about a transatlantic subsea cable
Speaker 1: by the end of this episode. That came a little
Speaker 1: more than a decade after that. And to think of
Speaker 1: it being ten years, a little more than ten years
Speaker 1: between stringing sixty kilometers of cable between two cities in
Speaker 1: America to laying a subsea cable across the Atlantic Ocean
Speaker 1: blows my mind. Well, anyway, the demonstration was a success,
Speaker 1: and it didn't take long for railroad companies to start
Speaker 1: building out tell alegraph systems, and early on they were
Speaker 1: almost exclusively used to help keep track of traffic on
Speaker 1: the rail system, to better plan out routes, and to
Speaker 1: avoid long delays or accidents. By the end of the
Speaker 1: eighteen forties, journalists were starting to make use of the
Speaker 1: telegraph system to wire stories across vast distances, and businesses
Speaker 1: began to get interested in this as well, the ability
Speaker 1: to be able to conduct business between cities without having
Speaker 1: to take you know, a train ride or otherwise have
Speaker 1: you know, like like people on horseback travel from one
Speaker 1: city to another. Because keep in mind this is this
Speaker 1: is before the automobile has really become a thing. So yeah,
Speaker 1: there were limited ways of getting information from one point
Speaker 1: to another. However, until eighteen fifty, these distances were all
Speaker 1: over land. The reach of telegraph systems ended at the coastlines,
Speaker 1: which meant that while regions could develop a sophisticated internal
Speaker 1: communications system you know, inside their border or maybe between
Speaker 1: borders of neighboring nations that shared you know, a land border,
Speaker 1: once you hit the ocean, you had to rely on
Speaker 1: other methods, much slower methods. So a mail ship isn't
Speaker 1: a ship that carries mail, not a not a gendered ship,
Speaker 1: but a mail ship between London and New York could
Speaker 1: take nearly a month to travel across the ocean. A
Speaker 1: fast one might be able to make the journey in
Speaker 1: three weeks. By the mid nineteenth century, steamships were largely
Speaker 1: taking the place of sailing vessels. They could make the
Speaker 1: journey in up around ten days, so still more than
Speaker 1: a week to get from one point to another. That's
Speaker 1: pretty slow for news to travel. It was difficult to
Speaker 1: act with alacrity if you were relying upon information from
Speaker 1: across the pond. So there was a strong use case
Speaker 1: to make for creating an undersea cable infrastructure that could
Speaker 1: connect distant parts of the world, you know, parts that
Speaker 1: were separated by oceans, and even in Europe, like England
Speaker 1: in particular, saw the need to do this because while
Speaker 1: the distance was not nearly as great to travel from
Speaker 1: say Dover to France, the delay in getting information from
Speaker 1: other parts of Europe was still pretty considerable, so there
Speaker 1: was definitely a need for that as well. This did, however,
Speaker 1: present some engineering challenges because you had to find a
Speaker 1: way to make this both practical and affordable. Now this
Speaker 1: is going to be obvious, but I need to establish it.
Speaker 1: It is way easier to repair and maintain infrastructure that's
Speaker 1: above the water than it is to do below the water.
Speaker 1: And that's because we live above the water and we
Speaker 1: can't live below the water, at least not with the
Speaker 1: same amount of freedom. And since the Mr folks seemed
Speaker 1: completely uninterested in helping us maintain communication channels. We have
Speaker 1: to take that into consideration. To that end, we have
Speaker 1: to treat cables subseed cables different from terrestrial cables. We
Speaker 1: have to take into consideration what being submersed in ocean
Speaker 1: water is going to do to a cable over time.
Speaker 1: We have to understand that those effects can be detrimental.
Speaker 1: We have to be able to estimate how long a
Speaker 1: particular cable is likely to remain viable, assuming no catastrophic
Speaker 1: instances occur, like assuming that a ship's anchor doesn't tear
Speaker 1: through the cable, for example. So we have to make
Speaker 1: sure that we have the budget to not just install
Speaker 1: a cable in the first place, but to potentially replace
Speaker 1: that cable when we near the end of its estimated lifespan.
Speaker 1: It has to make financial sense, or else it's a
Speaker 1: loss in the long run. Right. So you can argue, yes,
Speaker 1: it's invaluable to have two distant places connected together, but
Speaker 1: if you're constantly having to replace the communication channel, then
Speaker 1: that invaluable might start to take on of value where
Speaker 1: you just say, yeah, it's invaluable, but I don't want
Speaker 1: to pay for it. So coming up with a way
Speaker 1: to make subsea cables work extends beyond just the technology.
Speaker 1: I mean, obviously the tech is a critical component or
Speaker 1: else nothing happens. But you can't ignore the financial element,
Speaker 1: right or the physical challenges, because if you do that,
Speaker 1: you're setting yourself out to fail. So we're gonna take
Speaker 1: a quick break. But when we come back, we're gonna
Speaker 1: talk about a couple of other things before we get
Speaker 1: to the first subseed cable, like some basic things about
Speaker 1: electrical transmission. But before we do that, let's take this
Speaker 1: quick break. All right, So in the eighteen twenties and
Speaker 1: eighteen thirties you had all these various smarty pants is
Speaker 1: is all learning about electro magnetism. And we now know
Speaker 1: that if you pass an electric current through a conductive material,
Speaker 1: that generates a magnetic field. And similarly, should you have
Speaker 1: a conductive material like a wire, encounter a magnetic field,
Speaker 1: that field will induce an electric current to flow through
Speaker 1: the conductive wire. And you've probably played with this in school,
Speaker 1: making a simple electro magnet with like an iron nail,
Speaker 1: some copper wire, and a battery. You know, you connect
Speaker 1: the wire to either terminal of the battery, you've coiled
Speaker 1: the wire around the nail to act as a core,
Speaker 1: and it becomes magnetic. You can pick up paper clips
Speaker 1: and stuff. I remember I did that in school. I
Speaker 1: imagined that people still do well. There's a whole lot
Speaker 1: more to electro magnets, but we're just going to focus
Speaker 1: on a couple of little things first. And the first
Speaker 1: important bit is, because of this relationship between electricity and magnetism,
Speaker 1: we need to make sure that wires and cables that
Speaker 1: we use to transmit electricity have really good insulation around them.
Speaker 1: And that's because us Without insulation, that is, without some
Speaker 1: sort of barrier that resists the flow of electricity and
Speaker 1: the interaction of magnetic fields, you have the potential for interference.
Speaker 1: So let's say you've got two copper cables and there's
Speaker 1: no shielding on them, you don't have any insulation on them,
Speaker 1: and you've got them close to each other. And then
Speaker 1: let's say you send electricity through one of those two cables,
Speaker 1: not the second one, just cable number one. Well, as
Speaker 1: the electricity flows through cable number one, that creates a
Speaker 1: magnetic field which overlaps to the second cable, and that
Speaker 1: induces a current to flow Now, if we're using direct
Speaker 1: current something like a battery, uh, the second cable will
Speaker 1: only have electric current running at the very beginning when
Speaker 1: that magnetic field first hits it, but then it will stop. However,
Speaker 1: if the source is alternating current then which means that
Speaker 1: the current is changing direction many times per second, then
Speaker 1: what you have is a fluctuating magnet at it field.
Speaker 1: Because the magnetic fields direction also changes many times per second,
Speaker 1: that will continue to induce electricity to flow in the
Speaker 1: second cable. This would be in interference. It creates phantom
Speaker 1: signals when no signal is intended, or it interferes as
Speaker 1: one signal overpowers or changes another. I remember back in
Speaker 1: the day, I had these cheap desktop speakers that I
Speaker 1: had connected to my computer, and I would put my
Speaker 1: cell phone down on the desk, and every time my
Speaker 1: cell phone got a notification, it would make this weird
Speaker 1: electric chirping noise in the speakers because that was radio
Speaker 1: frequency interference that was inducing a current to flow through
Speaker 1: the speakers. So these are things that can happen, and
Speaker 1: you don't want them to write. You want to shield
Speaker 1: your components so that only the signals you want to
Speaker 1: send are going through so you have to protect a
Speaker 1: against that. Now, in the nineteenth century, there were people
Speaker 1: who discovered a plant that had a kind of sap
Speaker 1: essentially that was found to be a really effective insulator,
Speaker 1: so it resisted the flow electricity and protects or insulates
Speaker 1: against interference. That material is called Gutta percha. It's a
Speaker 1: biologically derived latex. And like I said, the plant has
Speaker 1: the name Gutta percha, but that's also the name everyone
Speaker 1: used for the derived latex from it. Now, this was
Speaker 1: fortunate at the time, but I should also add that
Speaker 1: the telecommunications industry would spell doom for the Gutta purchase
Speaker 1: trees because the rampant harvesting of the trees created an
Speaker 1: unsustainable situation. And before too long people realize, oh, we
Speaker 1: need an alternative to this, because pretty soon there's not
Speaker 1: going to be any of this plant left on the
Speaker 1: planet will have harvested at all. Anyway, Gutta percha has
Speaker 1: many of the same properties as synthetic rubber, including the
Speaker 1: ability to insulate conductive materials. Next, we need to think
Speaker 1: about what happens with electricity as it travels over greater
Speaker 1: distances of wire um. This is going to get more
Speaker 1: complicated later in this episode, because, as it turns out,
Speaker 1: there are certain things that we have to take into
Speaker 1: consideration with any length of cable, and then there are
Speaker 1: other things that come into play when you're talking about
Speaker 1: cable that happens to be under the water. But under
Speaker 1: most circumstances, even a great electrical conductor has some level
Speaker 1: of resistance. Now I say under most circumstances, because as
Speaker 1: it turns out, if you're able to super cool a conductor,
Speaker 1: like a good conductor, and you're able to get it
Speaker 1: down to an incredibly low temperature, like just a few
Speaker 1: units of kelvin above absolute zero, then you can have
Speaker 1: a superconductor which has no resistance. But under most normal conditions,
Speaker 1: you know, conductors have resistance to electricity. You can think
Speaker 1: of electrical resistance as kind of being like friction. It's
Speaker 1: working against or resisting the flow of electricity. So resistance
Speaker 1: depends upon a few different factors, such as the material itself,
Speaker 1: like some conductors are better than others, like coppers a
Speaker 1: really good conductor, and it also depends upon the thickness
Speaker 1: of that material. A thin copper wire has a greater
Speaker 1: electrical resistance than a thick copper cable for example. Well,
Speaker 1: resistance means that as you transmit electricity across this conductor,
Speaker 1: you'll see the electrical energy diminish over distance. And we
Speaker 1: know that energy can be neither created nor destroyed, right,
Speaker 1: so we're not destroying that energy. However, that energy is
Speaker 1: converting from one type to another. In this case, the
Speaker 1: resistance causes the conductive material to heat up and we
Speaker 1: lose some of that electrical energy in the form of
Speaker 1: waste heat. So if you want to push electricity further
Speaker 1: down a trans mission line, you really have to use
Speaker 1: a lot of voltage. And remember voltage is the pressure
Speaker 1: in this system. So with alternating current, we can actually
Speaker 1: use devices called transformers, which, while they are not robots,
Speaker 1: they are arguably more than meets the eye. If you
Speaker 1: were to look at an electrical transformer, like open up
Speaker 1: a cover, and by the way, never do that, but
Speaker 1: if you did do that, you would see that consists
Speaker 1: of two coils of conductive wire wrapped around a core,
Speaker 1: usually a ferro magnetic iron core in a simple transformer,
Speaker 1: not necessarily a solid core, but a core. So passing
Speaker 1: electricity through one coil of this wire induces electricity to
Speaker 1: flow through the other. We already talked about inductance, right,
Speaker 1: and the number of turns in each coil determines a
Speaker 1: change in voltage. So let's say we've got coil number one,
Speaker 1: which will call the primary coil. This is the coil
Speaker 1: where we're going to send electricity through the wire. Let
Speaker 1: say that primary coil has five turns and coil number two,
Speaker 1: which is our secondary coil, has ten turns. Well, then
Speaker 1: the ratio of turns is one to two, one for primary,
Speaker 1: two for secondary, and the voltage of the second coil
Speaker 1: will be double that of the first coil. This is
Speaker 1: a step up transformer. We're stepping up the voltage. We're
Speaker 1: increasing it by a factor of two. Now, if the
Speaker 1: primary coil has ten turns and the secondary coil has
Speaker 1: five turns, that's a two to one ratio. That means
Speaker 1: the voltage of the second coil will be half that
Speaker 1: of our first coil. This is a step down transformers.
Speaker 1: So using this we can then push voltage up on
Speaker 1: terrestrial power lines that are using alternating current. Again, this
Speaker 1: only works with alternating current, not direct current. Then you
Speaker 1: can increase the voltage for long distance transmission. You can
Speaker 1: overcome the problem of loss due to resistance. Essentially, you've
Speaker 1: just you turned the pressure on so much that it's
Speaker 1: it's powering through that. Now you have to have the
Speaker 1: right kind of cables to make that happen. You have
Speaker 1: to have the transformers along the way, and you have
Speaker 1: to step down the voltage before you feed that current
Speaker 1: into say a business or a house. But it's entirely
Speaker 1: possible to send electricity long distances overground using transformers. Anyway,
Speaker 1: it's one thing to have a transformer above the waves.
Speaker 1: If you've ever been around when a transformer blows out,
Speaker 1: you know that this is a spectacular and often terrifying event.
Speaker 1: There's a very loud boom, and it's like a thunderclap
Speaker 1: or a shotgun going off, and then there's a shower
Speaker 1: of sparks, and then all the power goes out and
Speaker 1: it happens like in that order instantaneously. It seems now
Speaker 1: that is inconvenient here upon the surface world, but below
Speaker 1: the waves that would be much worse. So we have
Speaker 1: to keep that in mind when we're talking about subsea cables.
Speaker 1: Some of the solutions that we have to us here
Speaker 1: on the surface would not be available to us underwater.
Speaker 1: Now Samuel Morse himself tested the viability of an underwater
Speaker 1: telegraph cable. He used a wire coated in tar and
Speaker 1: India rubber to insulate the wire from the water because
Speaker 1: he didn't want to lose electricity through the water. Essentially,
Speaker 1: he submerged the wire in the New York Harbor and
Speaker 1: he sent a telegraph signal through it, and the experiment
Speaker 1: was a success. This signal came out the other side.
Speaker 1: It worked. So as early as eighteen forty two, engineers
Speaker 1: understood that an undersea cable was possible. The question was
Speaker 1: could be made practical. The first underwater cable using Gutta
Speaker 1: Percha as an insulator, was laid between Deut's and Cologne
Speaker 1: across the River Rhine in eighteen forty seven, and then
Speaker 1: in eighteen forty nine and Electrician with the Southeastern Railway
Speaker 1: succeeded in laying two miles of cable off the coast
Speaker 1: of England around the Kent region. But the first commercial
Speaker 1: subseed cable would follow the year after that. It was
Speaker 1: eighteen fifty and two brothers, Jacob Brett and John Watkins
Speaker 1: Brett created the English Channel Submarine Telegraph Company. Now the
Speaker 1: brothers had proposed laying a cable under the sea through
Speaker 1: the English Channel and connecting the port towns of Dover,
Speaker 1: England and Calais, France. Both England and France agreed to
Speaker 1: this proposal, so the brothers got the funding they needed
Speaker 1: to to try and make it happen, and they had
Speaker 1: a deadline that they had to meet. So the brothers
Speaker 1: purchased cable from a company called the Gutta Purchase Company.
Speaker 1: The cable had Gutta Purchase insulation on it, but it
Speaker 1: had no armoring to protect it from other hazards. So
Speaker 1: it's a copper cable with a rubber like insulating layer
Speaker 1: on the outside and that's it. Uh. It was just
Speaker 1: a single copper wire too, it was not We're not
Speaker 1: multiple cables or wires in this. So in many ways
Speaker 1: this would be an experiment and ultimately it would be
Speaker 1: only partially successful. Uh. In that really it was a failure,
Speaker 1: but it taught them a lot of lessons. So the
Speaker 1: cable the brothers used was too light to sink on
Speaker 1: its own. It would not sink down to the sea floor.
Speaker 1: So every one hundred yards or so, workers on board
Speaker 1: the ship that would unspool the coil of cable, had
Speaker 1: to attach lead weights to the cable. The weights ranged
Speaker 1: between ten to thirty pounds, and the company used a
Speaker 1: steam paddle ship called the Goliath to carry the cable
Speaker 1: across the channel. They attached one end of the cable
Speaker 1: to the dover shore side of the connection that went
Speaker 1: up to a telegraph station, and then they began the
Speaker 1: journey to France, and the ship would have to stop
Speaker 1: every one yards or so in order to sink another
Speaker 1: weight down with the cable to keep it in place
Speaker 1: on the ocean floor, and had to stop each time.
Speaker 1: So it's not like, you know, they were just leading
Speaker 1: this out and staying in motion the whole time. They
Speaker 1: stopped every hundred yards. It took the whole day for
Speaker 1: the ship to lay the cable across to reach France,
Speaker 1: and there the team attached the cable on the French
Speaker 1: side they attempted to establish an electrical connection. I'm not
Speaker 1: entirely sure the outcome of that attempt, Like the accounts
Speaker 1: I read don't seem to really indicate whether or not
Speaker 1: they were successful in getting an electrical signal all the
Speaker 1: way across. At any rate, if they did, it was
Speaker 1: a week one and by the next morning, the connection
Speaker 1: had been severed and the line was just totally dead.
Speaker 1: Not long after that, stories began to circulate that some
Speaker 1: French fisherman had accidentally dredged up the cable in some
Speaker 1: netting and then subsequently severed the cable. However, that story
Speaker 1: was never verified. It didn't stop people from spreading variations
Speaker 1: of that story, including variations that made the fisherman look
Speaker 1: increasingly dimwitted over time. But the stories that were published
Speaker 1: immediately following the failure actually suggested that it was the
Speaker 1: action of the waves off the rocky coast of France
Speaker 1: that was making the cable rub against rocks and then
Speaker 1: and then break that way. What was certain is that
Speaker 1: the cable did break, whether it was a human caused
Speaker 1: error or because of the action of the waves, and
Speaker 1: that's probably because there was no armoring on the cable.
Speaker 1: So there you go. The brothers sent a letter to
Speaker 1: the Times in England explaining that while their first attempt failed,
Speaker 1: they had learned a great deal in the process, and
Speaker 1: they explained that the thing that they had attempted had
Speaker 1: never been done before, and as such they were going
Speaker 1: in ignorant of what would and wouldn't work. But through
Speaker 1: this experience they had learned some valuable lessons and were
Speaker 1: more convinced than ever that a cable connecting England to
Speaker 1: the European continent would work. Whether they wrote that letter
Speaker 1: in an effort to, you know, make sure they still
Speaker 1: had funding for future attempts, or this was a genuine
Speaker 1: expression of their enthusiasm, I don't know. Maybe it was
Speaker 1: a mixture of both, or maybe it was something else entirely.
Speaker 1: But the important thing is they were right. When we
Speaker 1: come back, I'll explain and tell the rest of their story,
Speaker 1: all right. So the Brett brothers still had some time
Speaker 1: left before their agreements with France and England would expire,
Speaker 1: specifically with the French government, and if that happened, they
Speaker 1: were going to have to go through the whole process
Speaker 1: of securing permission all over again. That was not a guarantee,
Speaker 1: especially you know, after having failed their first try. So
Speaker 1: they were determined to make another go at it before
Speaker 1: time was up, and this time they would add more
Speaker 1: protections for the cable. That cable would contain not one,
Speaker 1: but four copper wires, each insulated by Gutta percha. In fact,
Speaker 1: h wire had a double layer of Gutta purchase installation,
Speaker 1: so that you had a wire that was the core,
Speaker 1: and then you had a rubber case essentially on the
Speaker 1: outside of that, and then a second rubber case on
Speaker 1: the outside of that. The engineers then bound those four
Speaker 1: wires together with yarn soaked in tar and tallow, so
Speaker 1: together the yarn tar tallow mixture. There's some other stuff
Speaker 1: in there as well, and the four wires encased in
Speaker 1: Gutta percha served as the core of the cable itself,
Speaker 1: and that soaked yarn provided some more stability and strength.
Speaker 1: The bound cables now formed a kind of rope, and
Speaker 1: the next step was to weave ten strands of galvanized
Speaker 1: iron wires around the rope to provide armor protection. Galvanization
Speaker 1: is a process through which you apply a protective coating
Speaker 1: of zinc into onto something like iron or steel. Typically,
Speaker 1: the way it works is you make whatever thing you're
Speaker 1: making out of iron or steel, and then you immerse
Speaker 1: that in molten zinc, which then adheres to the exterior
Speaker 1: of the metal. That helps prevent rusting, which has an
Speaker 1: important consideration if you've got a cable that's going to
Speaker 1: be submerged in salt water. Throughout its lifespan. You know,
Speaker 1: saltwater will cause stuff to rust pretty darn quickly. So
Speaker 1: the iron wires were protected with this zinc coating and
Speaker 1: the they were they measured about five six of an
Speaker 1: inch in diameter, and like I said, there were ten
Speaker 1: of them that would be woven together to create the
Speaker 1: armored sheath for this cable. Now, according to a piece
Speaker 1: in the Illustrated London News, the brothers employed an engineer
Speaker 1: named George Fenwick, who invented and built a machine in
Speaker 1: just ten days to weave these iron wires around the
Speaker 1: cable of you know, copper wire and yarn. And it
Speaker 1: had to be fast, and it had to be delicate.
Speaker 1: It could not damage the copper itself. If the copper
Speaker 1: broke inside the rope, then you could have a broken connection.
Speaker 1: I would love to describe this machine to you, but
Speaker 1: I've only seen a few descriptions without visual aids. I
Speaker 1: think I would really do a poor job of explaining it.
Speaker 1: But let's talk about what the machine had to do.
Speaker 1: It had to draw this rope, this this cable of
Speaker 1: yarn and copper wires through a machine and had to
Speaker 1: weave around that rope the iron wires in a pattern
Speaker 1: that was tight enough to provide armor protection for the
Speaker 1: copper inside, and it had to do it without breaking
Speaker 1: the copper. The machine was able to draw off eleven
Speaker 1: inches of cable in a single revolution of its steam engine,
Speaker 1: and it had a revolutions per minute speed of eighteen,
Speaker 1: so it would revolve eighteen times and eleven inches of
Speaker 1: cable would go through each revolution. That means that if
Speaker 1: I'm doing my math correctly, it could weave the iron
Speaker 1: armoring for sixteen and a half feet of cable every minute,
Speaker 1: which is pretty impressive now, granted they're making miles and
Speaker 1: miles of cable. In fact, overall the primary cable was
Speaker 1: twenty four miles long, and it took about three weeks
Speaker 1: to make the whole thing, And the plan was to
Speaker 1: use those twenty four miles of cable to span the
Speaker 1: twenty one miles of distance between Dover and Clay, the
Speaker 1: thought being that the three extra miles would be plenty
Speaker 1: to deal for the fact that you're sinking it under
Speaker 1: the water. As it turns out, the cable wasn't quite
Speaker 1: long enough to reach, so in the end they actually
Speaker 1: had to splice an additional mile of cable onto the
Speaker 1: French side of this in order to make a connection work.
Speaker 1: But fortunately that would work out. Now, the twenty four
Speaker 1: miles of cable, the primary cable weighed around a hundred
Speaker 1: eighty tons and when it was coiled up, it made
Speaker 1: a coil that measured fifteen feet in diameter on the
Speaker 1: inside of the coil thirty feet in diameter on the
Speaker 1: outside of the coil. Once constructed, cruise loaded the cable
Speaker 1: onto a steamship called the Blazer. Now the ship was
Speaker 1: pretty much gutted before the cruise loaded the cable onto it.
Speaker 1: They pretty much stripped it of everything and essentially it
Speaker 1: became a barge that would be pulled by tug boats,
Speaker 1: a pair of them. Now this was in Wapping, an
Speaker 1: area in London on the Thames River, so the tug
Speaker 1: boats would tow the Blazer out the Thames, down to
Speaker 1: the sea and around the coast of England to Dover. Now,
Speaker 1: the laying of the cable would not go smoothly. For
Speaker 1: one thing. While the iron weaving machine was a work
Speaker 1: of genius, and while it was able to work pretty quickly,
Speaker 1: it was not always flawless. Um there were some breaks
Speaker 1: in the iron wires along the length of the cable,
Speaker 1: so you had little bits where, you know, a strand
Speaker 1: of iron would be broken a little bit and it
Speaker 1: would start to stick out. This created surfaces upon which
Speaker 1: something could snag you weren't careful. This would become important
Speaker 1: as the crew laid the cable between Dover and Calais,
Speaker 1: and the first problem popped up right away. So the
Speaker 1: coil still aboard the blazer, which again was being towed
Speaker 1: by some tug steamers, snagged as it was uncoiling and
Speaker 1: they were laying the cable into the sea. So the
Speaker 1: tug boats had started moving a little too quickly. They
Speaker 1: got up to a top speed that was like five knots,
Speaker 1: which isn't super fast, but it was too fast to
Speaker 1: uncoil the cable safely. And one of those broken iron
Speaker 1: wires snagged on a surface as the the cable was
Speaker 1: being uncoiled and put into the ocean, and an eighteen
Speaker 1: yard length of that cable was stripped of that one
Speaker 1: strand of iron wire, not the whole iron casing, but
Speaker 1: one of the ten strands of wires stripped away. Now
Speaker 1: the armor consisted of ten iron wire, so this was
Speaker 1: not you know, a true disaster, but it did send
Speaker 1: the message that they needed to go a little more slowly,
Speaker 1: which was tough because the weather was also really bad,
Speaker 1: so spending more time out in bad weather on the
Speaker 1: sea not a high priority. But the captains of the
Speaker 1: tug boats were told don't hit the steam quite so hard.
Speaker 1: Then the weather started getting rough and the tiny ship
Speaker 1: was tossed, so to speak, And as the ships got
Speaker 1: closer to France, the seas were very heavy and a
Speaker 1: strong wind was blowing, and at one point the tow
Speaker 1: rope connecting the Blazer to the tug ships snapped and
Speaker 1: the Blazer was set adrift, and it took some time
Speaker 1: to reconnect the Blazer to the tug ships, during which
Speaker 1: the Blazer had drifted about a mile and a half
Speaker 1: off course. The delay meant that it was near nightfall
Speaker 1: when they were finally approaching France, and the storms in
Speaker 1: the darkness meant conditions were just too dangerous to complete
Speaker 1: the connection, so the Blazer anchored for the night. The
Speaker 1: next day, the weather was not much better, and the
Speaker 1: tug ships pulled the Blazer to within a mile of
Speaker 1: the shore of France, but they couldn't really get any
Speaker 1: closer because of the weather. So the crew decided to
Speaker 1: attach the end of the cable to a buoy, and
Speaker 1: this freed up the Blazer and the tug ships towed
Speaker 1: it back to England. Now the captain of another ship
Speaker 1: called the Fearless took over his ship, took up the
Speaker 1: end of the cable that was secured to the buoy,
Speaker 1: and then brought a little bit further, like another hundred
Speaker 1: yards or so, and then moored the cable. And the
Speaker 1: next day representatives from the Gutta Perch Company UH they
Speaker 1: joined the Fearless and they brought along with them an
Speaker 1: additional mile length of cable. So then the crew spliced
Speaker 1: the two cables together and formed a new one. And
Speaker 1: then they brought the fresh length of cable onto shore
Speaker 1: of France after much delay, and a French crew then
Speaker 1: laid the cable up to the French connection uh not
Speaker 1: the movie, but the actual connecting terminal point for the
Speaker 1: French side of the telegraph system, and the crew also
Speaker 1: buried some of the cable to keep it protected. Upon
Speaker 1: testing the cable, the teams were pleased to find out
Speaker 1: that they had established a working signal line between Dover
Speaker 1: and Calais and they actually did a heck of a
Speaker 1: demonstration to prove that it was working. It's one of
Speaker 1: my favorite stories about testing the technology. Okay, so here's
Speaker 1: what they did. At Calais. There are fortifications, it's a
Speaker 1: port town on France, and that's across the English Channel
Speaker 1: from England. England and France had had sometimes a contentious
Speaker 1: relationship in history. So there were ramparts along parts of
Speaker 1: Calais and on them was a cannon. So engineers connected
Speaker 1: the cannon to this electrical signal line connected back to England,
Speaker 1: and a current with sufficient voltage would ignite the cannon
Speaker 1: sign system, which would then cause the cannon to fire
Speaker 1: and so many miles away across the English Channel, an
Speaker 1: engineer sent a pulse of electricity from Dover, England to
Speaker 1: go through the subsequent cable, and that provided the juice
Speaker 1: necessary to make a cannon in France fire. Obviously, this
Speaker 1: was not the first time that the English made the
Speaker 1: French fire a cannon, but at least this time there
Speaker 1: were no hostilities involved. Now, the telegraph in this case
Speaker 1: used the pointing needle mechanism that I referred to earlier,
Speaker 1: rather than Samuel Morris's version that makes sense. Morse code
Speaker 1: when it was first introduced, only had codes for the
Speaker 1: letters that we typically encounter here in America. So in
Speaker 1: America it's pretty unusual to run into characters that have
Speaker 1: an accent on them, like an accent ague, for example,
Speaker 1: or letters that have an oomb out or anything like that.
Speaker 1: Over in Europe it's more commons, so they needed to
Speaker 1: have a method that would allow for that. Now, despite
Speaker 1: all the bumps along the way, the cable seemed to
Speaker 1: work exactly as was intended. The insulation around the copper
Speaker 1: wires remained secure even after some of that iron armor
Speaker 1: had been stripped off. The cable and the Submarine Telegraph
Speaker 1: Company that the name had simplified over the years received
Speaker 1: some criticism for putting the entire endeavor at risk because
Speaker 1: they did this operation during unfavorable weather. Essentially, some people
Speaker 1: were saying, you're really lucky that this works, because you're
Speaker 1: an idiot for having to lay down subseed cable when
Speaker 1: the cs are so rough. However, in defense of the company,
Speaker 1: they didn't really have a choice in the matter because
Speaker 1: they were rapidly approaching the deadline that France had set,
Speaker 1: and if they did not get the cable laid in time,
Speaker 1: then the whole project was going to be a failure
Speaker 1: and all the money was going to go away. So
Speaker 1: really this all happened in the nick of time, and
Speaker 1: those risks were necessary once if they wanted to actually,
Speaker 1: you know, make this work now. To send signals through
Speaker 1: cables of great length, companies need to supply, like I said,
Speaker 1: a good deal of voltage to overcome resistance. But there
Speaker 1: were other issues that placed fundamental limits on how far
Speaker 1: or how fast you could transmit electricity and thus information
Speaker 1: across simple copper wire. So we're going to talk a
Speaker 1: little bit about that before I wrap up, and then
Speaker 1: in the next episode we'll talk more about the Transatlantic
Speaker 1: telegraph cables. So I've mentioned resistance and voltage and current,
Speaker 1: but things get significantly more complicated when we start talking
Speaker 1: about transmitting a signal across very long cables that are
Speaker 1: underwater or underground. Now, technically these things happen in shorter
Speaker 1: cables too, but if the distance is short enough, you
Speaker 1: might not even notice that there's a problem, or it
Speaker 1: may not be bad enough for it to be an issue.
Speaker 1: But we definitely see them over great distances with cables
Speaker 1: that are submerged or buried Michael Faraday, whom I've talked
Speaker 1: about frequently on this podcast a true Genius U He
Speaker 1: had a hypothesis about undersea cables or buried cables, and
Speaker 1: this was based off the observation that another smarty pants
Speaker 1: named Sir Francis Ronalds had observed way back in three
Speaker 1: He saw that if you had two insulated wires of
Speaker 1: equal length and gauge, and you buried one of them,
Speaker 1: and you tried to pass electrical signals through each of them,
Speaker 1: the above ground one would work just as you would expect,
Speaker 1: but the one that was buried would have trouble carrying
Speaker 1: the signal. The signals seemed to be moving more slowly,
Speaker 1: as if something were putting the brakes along the way.
Speaker 1: Faraday concluded that this was because of induction between the
Speaker 1: wire and the earth surrounding the wire, or, in the
Speaker 1: case of submerged sea cables, the water. So what does
Speaker 1: that actually mean. Well, essentially, the cable and the water
Speaker 1: behave kind of like a laden jar or liden jar.
Speaker 1: If you pass an electric current through the cable, it
Speaker 1: induces an electric charge and opposite electric charge in the water,
Speaker 1: and opposite charges attract one another. This attraction is kind
Speaker 1: of like putting the brakes down on a signal. It
Speaker 1: doesn't stop it, but it slows it down. They called
Speaker 1: it retardation of a signal. Faraday described the flow of
Speaker 1: electricity along and underwater cable as behaving like a wave,
Speaker 1: which honestly was really ingenious. He said that the result
Speaker 1: is you would first get a weak signal from the
Speaker 1: receiving end, and that signal would slowly grow in strength.
Speaker 1: Then the strength would start to fade away again, and
Speaker 1: this would happen in cycles again, very much like waves
Speaker 1: crashing on the beach. Then we've got William Thompson, who
Speaker 1: would later be known as Lord Kelvin, and they're super
Speaker 1: important scientist. Not only would he propose the system of
Speaker 1: absolute temperature, and we would later describe this in units
Speaker 1: called kelvin zero, kelvin being absolute zero, he was also
Speaker 1: instrumental in telegraphic engineering. Thompson built on Faraday's work, realizing
Speaker 1: that the diameter of the conductor was fundamentally important when
Speaker 1: determining the speed at which a signal will travel through
Speaker 1: a cable, and he also came up with an equation
Speaker 1: to describe how signals passed through cable, and it goes
Speaker 1: like this. The speed of a signal passing through a
Speaker 1: wire decreases as the square of the cable length increases,
Speaker 1: So signaling speed has an adversely proportional relationship to cable length,
Speaker 1: assuming that you're sticking with the same cable gauge. Gauge
Speaker 1: in this case relates to a cable's capacity and resistance.
Speaker 1: The larger the diameter of the cable, the lower the
Speaker 1: resistance will be. And we're going to stop here, but
Speaker 1: that issue that Lord Kelvin found would become um one
Speaker 1: of the big challenges to overcome when looking at laying
Speaker 1: very long subseed cable. So in our next episode we'll
Speaker 1: talk more about the quest to lay a cable along
Speaker 1: the Atlantic Ocean so that we could connect Europe to
Speaker 1: North America, and about the engineering issues that we needed
Speaker 1: to figure out, and then about how Lord Kelvin came
Speaker 1: up with even more important ideas about how to deal
Speaker 1: with this so that it could become practical. But we'll
Speaker 1: cover all that in our next episode. If you have
Speaker 1: suggestions for future episodes, be like and tricks send me
Speaker 1: a message on Twitter. The handle we use is text
Speaker 1: stuff hsw and I'll talk to you again really soon.
Speaker 1: Text Stuff is an I heart Radio production. For more
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