TechStuff Dives into Submarines

I'm your host, Jonathan Strickland. I'm an executive producer with I Heart Radio and How Stuff Works and a lot of all things tech and over on Twitter, a listener named Steve sent me a message asking me to do an episode about submarines, and I was sure I had done a full episode about submarines before, But then after I searched the archives, the best I could find was an episode I did with Scott Benjamin about personal submarines that was more about the expensive and frankly dangerous toys

of people who have way more money than they have self preservation instincts. So in this episode, I'm really going to cover the history of submarines and how they work. Actually, this is the first of a couple of episodes because the history is pretty long, and while I could have summarized the early history of submarines, I find that that

development is really fascinating. I mean, you think about what it would take to risk everything by building a contraption that can travel under the water where and you may not know this, people can't normally breathe so we're gonna look at the early history of submarines, not even getting into the twentieth century in this episode. Spoiler alert. So part of what makes this a fun topic to research is that you really get to see when humans first

began to suss out why stuff floats or sinks. Archimedes or Archie as I like to call him, wrote down the earliest account of why this is at least the earliest that we know of. There may have been earlier accounts, but this is the one that we know about. He described a force of a body partially submerged in a fluid that would then push that body upward. And the story goes that he figured this out while taking a bath, that he figured out that this force that would hold

a body up in water. Uh, was something that came to him while he was he himself was actually in water. And one of the principles that describes this force, it's called bullyancy. Essentially, it's saying that the amount of force that is exerted on the submerged object is equal to

the weight of the water that the object is displacing. Now, as a kid, I remember being a bit confused about this concept because you take a look at stuff around you, and you see what floats or sinks, and it it's not always you know, uh, intuitive to a child, or, if I'm going to be honest, to a young adult. It took me a while to grasp this thing because you know, like rocks sing in the water, right, rock sinks. But then you have giant ships, like enormous, huge ships

that are clearly much heavier than rocks are, and those float. Now, in my kid brain, I couldn't reconcile this. I mean, clearly it had to be the weight of stuff that determined whether or not it sank. Right, obviously, now that's not correct, But it took a while before my brain could wrap itself around the reasons why. So, the reason

is all about displacement water displacement. If the object displaces enough water so that the weight of the water it displaces is greater than the weight of the object, then the object will float. If the object displaces too little water so that the displaced water weighs less than the weight of the object, then it will sink. And really it comes down to density, not so much weight, but really density. So if the density of the object is less than that of water, it will float. If it

is greater than water, it will sink. And density and mass are pretty easy to confuse. For goofballs like me. Mass is how much stuff an object has. You know how much stuff is to that particular thing. A chair has a certain mass, but that's just part of an object's physical features. You also have to take into account the density, which is what you can think of as

the distribution of mass within an object. So a dense object is going to have its mass packed in more tightly than a less dense object of the same size. So you have to think about the size, shape, and mass of a thing before you'll know whether it will displace enough water to keep it afloat. Our comedees actually

used water displacement to determine density as well. So the basic formula for density is you take an objects mass and you divide it by the objects volume, And you would use scales to determine an object's mass, right, you would have weights that you knew equalled out to a specific amount of mass, like a kilogram weight, for example,

and you would weigh an object against that. But unless the object is of a standard sort of shape, like you know, a box, you might not have a neat and nifty formula you could use to describe its volume. You know, if it's an irregular shape, it's tricky. How do you figure out the volume of an irregularly shaped object. Well, you could use water, and that's because we know that water behaves with displacement in a very consistent way under

specific conditions. So one millilet of water will occupy one cubic centimeter of space. And this is specifically when water is at standard conditions, which a standard temperature is zero degrees celsius and standard pressure would be at one atmosphere. And that's because we want to make sure we're using standard conditions because you know, obviously water molecules will move apart as you heat them up, so you'll get some

expansion and more air pressure adds compressive elements. Although to be fair, water is extremely difficult to compress and that would change the measurements slightly. So under standard conditions we have this idea that water occupies one million leader or one million eader of water. Rather we'll occupy one cubic centimeter space. So an object completely submerged in water displaces or offsets a volume of water equal to the volume

of the object. So if you put an object in water at standard conditions and you have a little you know, measuring stick there that lets you read how much water has been displaced, and you see that the water has been displaced by a hundred millilaters, that would mean that the object you put in the water has a volume of one hundred cubic centimeters. One million leader equals one cubic centimeter. So then you would take the objects mass, you would divide it by that one dred cubic center meters,

and that would tell you what the object's density is. Now, water's density at twenty degrees celsius is one gram per cubic centimeter, So if the object's density is less than that, it will float. If it's greater than that, it'll sink. This is why giant warships made out of metal can cruise along the waves, and while they weigh a lot, the water they displace has much greater density, so the

boats will stay afloat. But what if you designed a vessel that could travel under the water, or better yet, you designed the vessel that could have some sort of control mechanism to allow it to either float or dive under the water. On top of that, there's another pesky problem to work out besides figuring out how to get

a vessel to go above or below the waves. Assuming this vessel is also meant to hold people, there has to be some sort of method for getting air to the people inside, as we don't tend to funk action too well if we can't breathe, So that also was a problem that had to be solved now. Since ancient times, we knew we could bring air down with us under water, but that air would only last a short while before the oxygen levels were too low to be useful and

we would asphyxiate. We didn't have a grasp on oxygen and carbon dioxide just yet, but we did know that you couldn't just keep breathing the same air indefinitely. Eventually you would have exhausted all the breathable air and you

would need to resurface. Aristotle wrote about diving bells, which are containers that could be lowered with the open side of the container facing the floor of the ocean or the lake or river or whatever, and they could be dense enough to sink even with the added buoyancy of the captured air inside the container, and water pressure would keep the air from escaping the container, and he wrote, quote, they enable the divers to respire equally well by letting

down a cauldron, for this does not fill with water, but retains the air in the quote, So essentially a diving bell. And that was way back in the fourth century b c. But that was also before we had susced out a way to replenish the air in the diving bell. So while you could use it to go underwater, you couldn't hang out for very long before you had consumed all the breathable air and you needed to resurface. So another problem is that water pressure that I just

talked about. It would compress the air inside a diving bell, so the air would take up less space inside the bell, and the bottom of the bell, assuming you're looking at it with the bottom being the open side, would fill a little bit with water. The water would come up a little bit along the inside of the container, which means you have a reduced work area as well a reduced amount of useful area where you, as a person

could inhabit and still breathe. One way to fix that would be to have a supply of pressurized air continue to come down into the bell. But it would take centuries to get that point. If you just included, say a breathing tube from the bell to the surface, well that wouldn't do any good at all. The water would just go right up the bell and up the tube a great deal. It's like if you put a straw inside a glass of liquid. You know, unless you cap the end of the straw, the liquid goes up the straw.

You don't have any way of pressurizing it to keep the water from coming in. So you would have to have this pressurized system and it would take hundreds of years to get to that point. So when it comes to getting really great details about the origin of submarines, we hit some pretty big snags. There are reports about them, but they aren't necessarily the most reliable. A lot of them are second or third hand reports, and they don't tend to have a whole lot of information about what

exactly happened or how it happened. But the general can census is that a design for what would be the first submarine that we have on record came from a guy named William Bourne born was an English mathematician way back in the sixteenth century, and the record of his design dates to fifteen seventy eight, so just to give you a little bit of context, at that time, England was ruled by Queen Elizabeth the First and Shakespeare was

just fourteen years old. Born's design called for a totally enclosed wooden boat, and then covering this wooden boat would be oiled or greased leather that would help keep the vessel water tight in order to reduce buoyancy. Borne's proposal was to have hand cranked vices that connected to the

interior of the boat's hull. Now, in some descriptions that I've read, it said that Borne intended to use the vices to pull the sides in a little bit like you're you're squeezing the boat from the in side, pulling the inner walls inward and reducing the overall volume of

the boat, thus increasing your density. An illustration seems to indicate that the idea was actually to have an inner chamber inside this vessel, and that uh the inner chamber, the innermost chamber where a person would be, would be waterproofed, and then you would have space between this inner chamber and these the hull or the outer sides of the boat, So you would have this secondary chamber on either side of the place where the operator would sit, and so

the visas would actually pull the boat's sections of whole inward and allow those parts of the boat to be flooded with water. So you're essentially pulling open almost like a trap door. You're pulling in sides of the hull of the boat. Water rushes in into a watertight section that it surrounds the inner chamber where the operator sits, and that would increase the density of the overall vessel. That's what would allow you to sink beneath the waves.

If that's the case, I'm not sure what the plan was to return buoyancy to the boat, because you would need to have some way to purge the water out of the space between the whole and the inner chamber while sealing the boat closed. Again, you have to have some way to force the water back out, otherwise you're not gonna You're not going to decrease the density and thus increase the buoyancy and be able to rise back up above the waves. And maybe that's why Bourne never

made the darn thing as far as we can tell. Instead, his design would remain an intriguing thought experiment for the time being. Skip ahead of Monarch to the time of James the First of England, and we do get to what most people consider to be the first submarine. A Dutch inventor named Cornelius van Drebble reportedly built a submarine, which he called a diving boat in the early sixteen twenties. Like Bourns proposed craft, Drebble's submarine was made of wood

and coated with greased leather. Propulsion came from ores that extended out the sides of the vessel. These oars, you know, the parts where the ore extended out from inside the boat. Those had to be coated with flaps of leather to create a waterproof seal, because otherwise they're going to get water coming into your submarine. That's bad business. According to accounts, it could dip as far as twelve or even fifteen feet beneath the surface of the water, and Drebble demonstrate

the craft along the Thames River in London. Supposedly, even Jimmy the King took a ride at one point. Now, if Drebble made any detailed records of how this boat actually worked, they have long since been lost. To time, we're not entire really certain what mechanism he relied upon

to get the boat to go underwater. Some people have suggested that the boat had some form of ballast barrels or bladders that could be opened which would allow water to come inside of them, increasing the overall density of the boat, and this causing it to sink beneath the waves, though I've not seen any description of how the vessel would then expel the water to regain buoyancy. Uh. In my just jettison the ballast, in which case then it

would rise up it's buoyancy would be returned. The earliest records I can find of any kind of ballast system

actually comes two hundred years after this particular example. Others suggest that perhaps the sloped shape of the bow that's the front part of the boat acted as a sort of reverse airplane wing, that when the boat began to move forward, the slope would cause the water to flow over the top of the boat, and that would push the boat downward into the wall watter uh, And that maybe with a system of weights could have added a

bit more downward force. I find that particular idea, the idea of forward motion creating the downward force to allow the boat to dive to be a little unlikely, simply because I don't think you'd be able to go very fast with oars. I don't think you could row fast enough to make that downward motion, uh strong enough to keep the boat underwater. You might bob a bit in the Thames, but I don't think you would be able

to go twelve to fifteen feet beneath the surface. That's just my own gut feeling there, because I don't think you could get up the speed necessary to maintain that. But we just don't really know for sure what the mechanism was. Drebble made sure that the vessel had a study supply of air by attaching to air hoses to the boat, and the other ends of the hoses were attached to floats that would drift on the surface of

the Thames above the boat. Now, I'm assuming that there must have been some method of pumping the air down into the boat, because otherwise you would have a problem. See, carbon dioxide is denser than air, which means you need a way to force breathable air down the hose to the interior of the submarine. Otherwise it would become saturated with C O two and you would eventually suffocate. This was something an inventor named de Lorena, an Italian inventor,

had figured out way back in fift thirty five. He made a diving bell with an apparatus that would replenish pressurized, breathable air into the bell. Though he took the secret of that invention to the grave. One other person reportedly understood how it worked, but had sworn an oath never to reveal it. So we don't know the precise methodology

used in that case either. Now, I'm sure it got stuffy and humid inside Drebble's boat, but at least you could get some air down there, and the crew wouldn't automatically just die of asphyxiation. So the submarine as a working, though primitive concept, dates back about five years, and I'm sure it will come as a shock to learn that since then we've made a few advancements. When we come back, I'll talk a bit more about some of the earliest subs and technology that made them work. But first let's

take a quick break. Okay, So, by the seventeen hundreds, several inventors had experimented with different designs for submersible vehicles, and they weren't really practical craft just yet, though the potential military applications were immediately apparent. So this was during the age when countries were imposing their will on others,

primarily through naval supremacy. Countries like Spain and England in particular were known for doing this, and a common tactic was to create a naval blockade around a port city to prevent ships from leaving or arriving at that port city. Creating a submersible that could secretly approach a blockade and disrupt it, typically through the use of explosives that some poor submarner would have to try and attach to those boats was an obvious application for a submarine. It would

be an incredibly useful war tool. In se we get the earliest published account of a ballast bladder, which some unknown inventor suggested using bags made out of goat skin to take in water so that submarine could dive below the waves, and the bags would have a twisting rod attached to them that would extend into the interior of the submarine itself, so the submarner could grab all of the rod and give it a good twist, and that in turn would twist the ballast bag and that would

force water out of the ballast bag. It would have a valve on the end of the bag so that the water couldn't just come right back in, and that would decrease the vessel's density and allow it to surface. This was a predecessor for ballast tanks essentially do the same thing, though you don't typically have to hand operate them these days. A few decades later, we have the first use of a submarine in war. That was the American Revolutionary War. There was actually a submarine in the

American Revolutionary War. The submarine was called the Turtle. And this was a pretty modest submarine. It's not like the Red October or anything like that. It could hold precisely one person. It was the design of David Bushnell, a an engineering student who was studying at Yale at the time. He and his brother Ezra built the dang Durn thing. The Encyclopedia Britannica describes the shape of the submarine as

a quote walnut standing on end end to quote. And if you see illustrations or the recreations of this particular submarine, you'll see exactly what they mean. It does kind of look like a sort of oval shaped submarine, large enough

to hold a single person on the inside. Facing forward from the submarine, at least from the perspective of the pilot, would be the propulsion system, which was a screw propeller and it worked on as similar principle as the Archimedes screw pump, which was used to lift water from areas

of low elevation to areas of high elevation. The submarine operator would crank a handle in order to turn this screw propeller, which would effectively pull the submarine through the water, and then with the other hand, the operator would control a rudder that is in the back of the vessel

to provide the steering mechanism. The vessel also had a secondary screw propeller, one that was oriented vertically, which meant it was meant to help the submariner navigate critically through the water, So if you were to dive beneath the waves, you would use the vertical screw propeller to push you down further into the water or to pull you up

to actually drive. The turtle had a chamber that would be flooded with opening a valve, and that would just decrease the ship's buoyancy, so it would start to sink uh to surface. The operator could work some pumps inside the turtle that would push this water back out of

that chamber. It also had ballast, both inside and attached to the outside of the vessel that was used to make sure the craft would maintain the proper orientation in the water and not just you know, start flipping over tilting to the side, which would be disastrous to the operator. So the weights were really meant to make sure that it maintained that up down orientation. Air came in through a pair of snorkels, and the snoricles had lids that

would close whenever the vessel were to go underwater. Windows on the hatch above the the operator would allow some light to come into the interior of the vessel, although it was meant primarily to be operated at night, and the design also meant that if you went underwater, you would have a limited supply of air because the snorkels now would be closed, and you would also have much

less light to work from. The intent was to operate so that only the hatch would be above the surface of the water for most of a mission, so that the operator would still be able to get a look around seeing where they were in relation to a target. They would also be able to breathe because the snorkels would be exposed to the air, and then the operator would only dive with the submarine in order to avoid being seen or when it came time to actually attach

an explosive device to the target. To do that, the ship had a drill that was also pointed up from the top of a turtle, and this was to drill a hole in a blockade ship, and then in that hole the operator could attach a line for a gunpowder charge. And this gunpowder charge was in the form of a mine with an ingenious clockwork fuse mechanism, which I'll describe

in just a second. Now, Bushnell had already conducted experiments while at Yale to find ways to make gunpowder explode underwater, which, as I understand it, caused a bit of a stir on campus. His mind was most likely a keg that was about two and a half feet long or about point seven six ms and one and a half feet in diameter or point for six meters, and it could hold about a hundred fifty pounds or about sixty eight ms of gunpowder to create a timing mechanism for the explosive.

He actually worked with a pair of clockmakers. They were known as a Phineas Pratt and Isaac Doolittle, And I just want to say that I'm really loving these names so far. Anyway, together Pratt, Doolittle and Bushnell came up with a clockwork device that would trigger a flintlock mechanism. It's the kind that you would find on a flint lock musket, and the flintlock would have a piece of flint and steel that would come together when the when the mechanism activated, it would uh spring shut and that

would cause a spark. And the idea was that the spark would then ignite a priming charge of gunpowder. The priming charge would in turn ignite the explosive charge. So the idea was that the sub operator would set a timer on this device and attached the mind to a ship using the hole that had been drilled into the ship's hull, and then they would try and get the heck out a dodge. They would be turning that hand crank frantically to move the propeller in order to get

a safe distance away from the explosive. The team's mind design would in theory give the operator enough time to get the hack away from the exploding ship, and it was a novel idea, but it turned out in practice to fall short of expectations. The Turtles target was a big one for its main mission. It was the HMS Eagle, which happened to be the flagship of the British Admiral Richard how As, the brother to General William how of

the British troops. But the Turtles drill turned out to be incapable of cutting through the eagles copper plated hull. By that time, dawn was breaking and the Turtles pilot, a soldier named Ezra Lee, was in danger of being discovered. So he attempted to sneak away, but he was spotted and the Eagle let out a pursuit boat. Lee decided that, well, the best thing for me to do is to set the timer on this mine, because if they're gonna get me, maybe they'll get the mind too and we'll all go

up together. So then he detached the mind from the Turtle, and the mind did explode. It did not blow up the pursuing boat, but it did scare them off, and it gave him the opportunity to actually make an escape. The Turtle would go on two more unsuccessful missions, one of them under the operation of Phineas Pratt himself, but nothing ever quite came of it, and the British eventually sunk a ship that happened to be carrying the Turtle,

and the submarine was lost in that particular engagement. But while the Turtle failed in its mission, the potential was obvious. They just had to refine the technology. Moving ahead a couple of decades, we come to Robert Fulton, an American engineer and inventor who perhaps is best known. Maybe he's most famously associated with steamboats, but in the early eight hundreds he also developed an early submarine and was also perhaps the most American of all classifications a capitalist. In fact,

you could call him an arms dealer. I'll explain. So in seventeen seven, Fulton was living in France and he goes to Paris and he pitches this idea for a submarine that he calls the Nautilus. Jules Verne would take note of this decade later, France and Britain have been involved in a series of military conflicts for more than a century. Uh In fact, some modern historians refer to

this as the Second hundred Years War. But the French looked at Fulton's proposal and they said manon, because they thought it was a dirty, underhanded way to fight a war. Because this was a time when people thought war was somehow better if everyone could see what everyone was doing all the time, and sneaky stuff was considered to be generally unfair. The mental gymnastics humans go through in order to determine what is and isn't a fair way to

kill each other never really fails to confuse me. And for the record, I'm pretty much against the whole killing thing entirely, but I realized that the world we live in makes that an impractical philosophy to be applied at

large in every situation. Anyway, Fulton appealed the decision and said, well, hey, what about um, how about I build this sucker pretty much on my own dime, and in return, if we use it to attack British ships, you can pay me, and that that payment will be based upon how big the ship was, how many guns it carried, and for British shipping vessels. You can give me a portion of

whatever you end up taking from those shipping vessels. And the French minister said that cord, which means okay, because heck, I mean the France wouldn't have to spend a single franc on this, and they would only have to pay out a portion of any spoils if the thing actually worked. So by eight Fulton had the Nautilus ready to go and he wanted to demonstrate its capabilities on the Sin,

the river that runs through Paris. And unlike the Turtle, the Nautilus had an iron ribbed hull coated with copper sheets. It also had a conning tower or con. Now, a ship's con is a designated area. It's typically raised above other areas, from which the commander of the ship can control or con the ship by issuing commands to the crew.

Future submarines would incorporate the con within a structure on the top side of the submarine called the sail or the fin, until technological advancements would render such an arrangement unnecessary. The Nautilus also had a collapsible mast and a sales system so that it could deploy a fan sail very similar to what would be found on a Chinese junk ship at the time. This would allow the Nautilus to

operate more like a classic ship when it's surfaced. The Nautilus was a cigar or tear drop shape, taking the basic form that we would see used in a lot of submarines moving forward. It was nearly seven meters long and two meters wide. They had horizontal wings or planes that were meant to aid in directing the ship's incline or decline as it was moving through the water. A section of the keel was a hollow chamber that could be flooded to increase the ship's density so it could

dive under the water. Hand powered pumps could push the water back out of the hull and thus returned the buoyancy to the ship and allow it to rise back up and and surface. Propulsion once again came in the form of a hand cranked screw propeller, and Fulton claimed that the ship could operate safely at a depth of thirty feet or nine meters, although a lot of people

were skeptical of that. Also, whenever he was doing demonstrations on the seine, he always made a point to go in the same direction as the current of the river itself, which gave the sense that this boat was actually able to move much faster than it really could in normal conditions.

The attack mechanism on this particular submarine was a spike with an eye in it, so you can think of it like a giant sewing needle, but attached to the eye was a cable, and attached the cable was a mine an explosive, and the mind was designed to explode upon coming into contact with an enemy ship's hull. Eventually, Fulton realized that he never build up the speed and forced necessary to penetrate a ship's hull with this spike, and so he decided instead to use a towed explosive

device called a carcass. Now it turned out to be moot, because when Fulton tried to use the Nautilus in a real world setting, it just couldn't keep up with the ships it was targeting. Ships could spot it and then maneuver out of the way, and this Nautilus was so slow it can never catch up. The French eventually canceled all contracts with Fulton, who then did the incredibly American

thing that I mentioned earlier. He switched sides. He had been marketing the submarine to the French to use against the British, so then he turned around to the British to sell them essentially the very same technology to be

used against the French. Robert Fulton, pioneering arms dealer. His attempts at using the submarine for the British were just as fruitless as they had been for the French, and the Breads were able to dominate the seas with their more conventional navy, and ultimately Fulton submarine would never see a successful wartime use and he would scrap it, focusing on steamboats instead. The next advances in submarines would arrive before and during the Civil War in the United States.

I'll explain more in just a second, but first let's take another quick break. In eighteen fifty five, a Bavarian engineer named Wilhelm Bower built a submarine for Russia. It was called the C Devil and it would require a crew of about a dozen sailors. Rather than a hand crank propeller, this submarine used a treadmill to provide the power needed to drive the propeller's motion, with four sailors

providing the foot power to do so. Bauer had built an earlier submarine back in Bavaria, but it had sunk on a test run, and Bower and two other men aboard had to actually wait while the vessel slowly filled with water until it reached a point where the pressure on the inside of the submarine had equalized enough to open the hatch and swim out. Because the water pressure outside the submarine was so great, they could not physically open the hatch the water weight was too great. Once

the pressure equalized, they were able to open it. Can you imagine sitting in a sunken submarine for hours waiting for there to be enough water in the summer so you can open up that hatch. It must have been terrifying. For that reason, Bower, in his Sea Devil design, included a primitive airlock so that the crew could escape if

such an event were to occur. With the new submarine, the Sea Devil had more than one thirty successful dives, including one during the coronation ceremony, in which the submarine

carried a four piece band which played beneath the water. Ultimately, the Sea Devil would end up getting stuck in the mud at the bottom of a river, reportedly because Russian admirals, who had grown envious of Bower's success and his favor with the Tsar, gave Bauer incorrect information about the depth of the water, so, according to the story, they sabotaged the effort. They said, oh, no, the river isn't that you know. The river is is something like forty ft deep,

when in fact the river was twenty feet deep. So then Bower dives further than what he actually can and get stuck in the mud. During the American Civil War, both the Union and the Confederacy experimented with submersible military boats.

The Union, for example, constructed a ship called the USS Alligator, and the U. S. Navy gave the job of building the Alligator to a firm called Nify and Levi, which in turn was following the designs of a French engineer named Brutus de Ville Roy or a de Ville Ras, if you prefer. The purpose of the Alligator was to

counteract ironclad Confederate ships like the Merrimack. Now, this contract called for a ship that was quote at least fifty six inches in width and sixty six inches in height and forty five feet in length, that equals out to one point four meters wide, about one point seven ms high, and about thirteen point seven ms long. The actual ship would end up being a little different from those dimensions,

but you get the rough idea. The original propulsion system of the Alligator was a set of ores that would need to be operated by twenty two sailors. That ended up being too slow and too crowded, so the Navy scrapped that in favor of a screw type propeller, and not only did that propeller provide a faster means of propulsion, it also reduced the crew needed to operate the propulsion

system to just eight sailors instead of twenty two. The submarine also had a diver lockout chamber, so again a very primitive airlock system, and it also was said to have an air purification system, but I couldn't find really any information on how that actually worked, so I don't really know what that was. You know, whether or not it was fully self contained within the vessel, or it

was a system of hoses and pumps, I don't know. Ultimately, the Alligator would be more of a headache and also a sunken cost literal as it turned out more than a viable military asset. It was being towed to South Carolina for its first true military mission, but during that trip bad weather struck and the towing ship had to cut loose the submarine, which was unmanned at the time, and the submarine ultimately sank beneath the waves and was lost.

The Confederacy built a semi submerged to torpedo ship called the c. S. S. David. This was not a true submarine. It could not dive beneath the water, but most of the ship's body was beneath the water. It was steam powered, though, which meant that it had to have a smoke stack to exhaust the smoke from the coal that they were burning in order to heat the boiler. And if you have a smoke stack, it's got to stick out over the water, so that part was always exposed to the air.

The ship was designed to hold four bowl three sailors and a commanding officer. At the front end was a long spar that had a torpedo at the very tip, so this was a boat that was meant to ram a ship, and the tip of the spar would explode upon contact. The David attacked a Union ship called the USS New Iron Sides on October Free while the David struck New Iron Sides and the torpedo exploded as planned.

The resulting splash of water slashed into the David and extinguished the fire for the ship's boiler, so now there was no power to the ship anymore. The commanding officer and one of the crew abandoned the ship. Technically, actually two of the crew abandoned the ship. The third crew member could not swim, so one of the other crew members swam back, and then those two guys were actually able to re light the boiler fire and then eventually

navigate away from the New irons Sides. Sailors aboard the New Iron Sides had been firing with small arms to against the David, but didn't do any significant damage. So uh, those two guys got away. The other two were actually captured. The most famous Confederate submarine was called the h L. Huntley, which was named after Horace Huntley, who designed it. The submarine used a spar torpedo similar to what the David had used, but unlike the David, the Hunley could actually

dive beneath the water. It carried a crew of eight, including the commanding officer. Sometimes some reports say could hold up as as many as nine, but eight was the standard crew and seven people were needed to hand crank the propeller. The eighth wooden man a rudder to steer the vessel. The vessel was nearly forty ft or twelve meters long, and inside the height of the vessel was just over four ft three inches or one point three meters, which meant it was pretty cramped and said that submarine

you could not stand, you know, tall in there. The ship had ballast tanks that could take on water and also expel it using hand powered pumps. The ship also carried weights to help act as ballast, and the weights could be quickly jettisoned if the ship needed to surface quickly, and it had a pair of snorkels that could bring fresh air into the vessel when it was close to the surface, Otherwise the ship was cut off from fresh air.

And according to some accounts, a single candle provided light inside the submarine, and it also provided a warning when the oxygen level was getting low because the candle's flame would begin to flicker. Part of the reason why the Hunley is famous is because it was responsible for a couple of dozen deaths, most of them Confederate soldiers, and

remember this was a Confederate ship. During the testing of the vessel, the Honley sank twice, the first result in the loss of five crewmen, and in the second accident, all eight of the crew died, including Hunley himself, who was at the time acting as the commanding officer. Even with those two accidents during the testing phase, the Confederacy salvaged the ship, repaired it for use, and put it

back into official military use. On February seventeen sixty four, the Hunley attacked the Union ship the Housatonic, which was a wooden ship of war, and the Huntley's attack was technically successful. The Housatonic did sink and five crew of the Hausatonic died as a result. However, the Huntley itself failed to return to port, and for many years no one was really sure what had happened. I mean, clearly, somewhere along the line the Hunley sank, but no one

was sure where or why. The Huntley, which was only in thirty feet or nine meters of water, remained lost until nineteen five years later. Crews were able to retrieve the Huntley. Upon opening the submarine, the retrieval crews were surprised to find that the Hunley's crew were all at their stations, which suggested there was no effort to abandon ship. There was no struggle to try and open the hatches or anything like that, which raises the question what actually

killed the crew before the ship had been unsealed. The general theory was that the crew had either suffocated or they had drowned, but the submarine had no signs of any damage that would have caused them to drown, So the leading hypothesis now is that the shock wave from the exploding torpedo actually killed the crew. A ruptured blood vessels in their lungs and led to them becoming incapacitated and then ultimately dying. However, we do not know for

sure what did it now. I'm going to conclude this episode with the description of one other early submarine built while the Union and Confederacy were both attempting to make practical use of submarines of their own. This ship's name was Le Planeur, and this was designed by a man

named Bourgeois in the late eighteen fifties. Actual construction began in eighteen sixty and it took a couple of years for it to be finished, And as far as I can tell, it was the first submarine to use a mechanical means of propulsion rather than relying directly on manpower. The submarine carried containers of compressed air, and the air served many purposes. It provided the power needed to drive

the propellers of the submarine. So you know, we released the compressed air and it moves the mechanical elements that actually make the propeller turn. So this was an air powered vehicle, and the subs engine was an eighty horsepower engine. The compressed air would also keep pressure inside the submarine greater than it was outside the submarine, which was said to be good to keep water from seeping into the vessel, which for submarines is considered to be a bad thing.

Tanks used to hold the compressed air were quite large. They needed to be to hold enough air to operate the submarine for longer than just a few moments. That meant that the size of the overall vessel had to be quite big as well. It measured one hundred forty feet long or nearly forty three meters far larger than any submarine before it. It required a crew of twelve sailors to man the ship, and the innovations were pretty important,

but the sub also had its share of drawbacks. One of those was that initially relied on a series of pipes and pistons inside the submarine that could move water around to act as ballast and to help provide stability as the ship was diving or where when it was climbing. Uh. And it was made more difficult because of the ship's size. Right, You've got a ship that's very long, and you get a sort of lever effect. Right, a small change at a pivot point would end up being a huge change

toward either end of the submarine. And unfortunately, the system wasn't able to react very quickly to changes in the ship's orientation, so a typical trip under the waves would be pretty harrowing. The ship would dive and the systems needed to correct its attitude in the water to level it out, would very slowly kick in, and then the ship would start to level out, but it would overcorrect and then it would start to climb and the whole

cycle would start up again. Now the system would be trying to correct for the change in attitude where now it's it's tilted up instead of down, and the process would keep going, so you had this see saw effect in the water as you're riding on the submarine. It could not maintain a level heading with zero buoyancy, and so ultimately the project was scrapped because it was just too risky. There needed to be more innovation in the field to stabilize the submarine so that it wouldn't be

so unmanageable underwater. Now. In our next episode, will continue down the path of history to explore how marine technology advanced over time and how modern submarines work today. But there's a lot more to cover that will probably skip around a little bit because in some cases we're talking about evolutionary changes where it's you know, important changes, important

significant innovations in submarine technology. But to cover every single one would be pretty exhausting, so I'll probably lump them together in sections. But that's for the next episode. If you guys have suggestions for future episodes of tech Stuff, send me a message. The email addresses tech Stuff at how stuff works dot com. Dropped by our website that's tech Stuff podcast dot com. You'll find links to where

we are on social media. You also find an archive of all of our past episodes up there, and there's a link to our online store, where every purchase you make goes to help the show, and we greatly appreciate it, and I will talk to you again really soon. Tech Stuff is a production of I Heart Radio's How Stuff Works. For more podcasts from I heart Radio, visit the i heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.