From the Vault: Pykrete

Mind production of My Heart Radio. Hey you welcome to Stuff to Blow your Mind. My name is Robert Lamb and I'm Joe McCormick, and we're gonna be talking about materials today. But this is a really fun materials episode that will shatter like glass in our hands, or will it. I guess it's a big question mark. Yeah, we're gonna be talking a lot about ice, but a lot of

exciting stuff about ice. You're gonna learn some new things about ice, I think, and you're also going to think, uh a bit more deeply about what can be done and also what perhaps cannot or should not be done with ice. So if you've read any of George rr. Martin's a Song of Ice and Fire. If you've read that saga, or if you've viewed the TV adaptation Game

of Thrones, you're well acquainted with the Wall. But to Reaquain everybody, this is a fantasy world that's based on sort of a medieval European model, and in the Far North you have this massive three hundred mile long, seven hundred foot tall wall of ice that we're told has stood there for eight thousand years as a barrier against the people's and the supernatural horrors of the Far North. Yeah,

it's basically Hadrian's Wall, except much bigger and made of magic. Yes. Yeah, we're told it was built by Brandon the Builder, with the aid of giants and the magical children of the forest. So we're definitely to understand that there is actual magic in its construction. But also there's this idea that Brandon was a master engineer, that he's in the vein of these various engineering cultural heroes that you see in various cultures.

But of course, the real standout feature that makes this wall unique is that it is built out of ice, not out of stone, but out of frozen water. Yes, it is a wall of ice. So um, you know, ignoring the magic for a second here, it sounds like a great plan, right. I mean humans have been known to make shelters out of ice, glaciers and snow have

served as natural barriers to travel. So why wouldn't it be ideal to construct this far northern barrier which is going to be dealing with, you know, with far northern climate, why not build it out of ice? Good question? Is a block of ice not just as good as a stone brick? Yeah? So I was looking around about this, and fortunately there is already a great book out there

that dives into this very question. It's titled Fire, Ice and Physics, The Science of Game of Thrones by Rebecca C. Thompson, PhD, a physicist and author of the popular Spectra series of comic books about physics. And I should also note that Sean Carroll wrote the intro. Cool so she Uh. First of all, this is just a really fun book if you if if you're interested in Game of Thrones and science, I encourage you to pick it up. But I love books like this. Uh, you know, I have one about done,

I've been eyeing one about Star wars um. But she goes through various aspects of the books and the world of West Roast and breaks them about scientifically, and does so in a very engaging, humorous but also um, you know, wester Roast loving style. So so there's there's one section in there where she tackles the wall and she points out that ultimately this question would an ice wall work. It's a lot more complex than you might think. So for starters, there's not just one type of ice crystal.

There are seventeen types of crystalline ice that we oh off. Plus there are three different types of a Morpheus ice and three theoretically says there might be as many as three hundred different phases of ice. Uh, you know, depending on some of the research out there. Right. The different phases of ice having different physical properties is something that's been explored in science fiction for a while. Actually, it's in the novel Cat's Cradle by Kurt Vonnegut, which invents

a fictional phase of ice. There is no actual phase of ice that does this, but there's a fictional phase of ice called ice nine, which acts as a seed crystal, and it is a it's a doomsday weapon because if you drop a piece of this ice into regular water. It will rearrange the structure of the regular water so that it freezes at room temperature, basically killing earth. Oh, you know, I've I've never read Cat's Cradle, but I

I remember now that you mentioned. I remember like reading that on a summary or the back of the paperback or something. Yeah. But but to clarify again, that's a fictional phase of ice. There is no actual phase of ice that does that that we know about. Yeah. The phase of ice we're most familiar with is ice one H, also known as ice phase one, and this is the hexagonal crystal form of ordinary ice. And this is pretty much all the ice you ever come into contact with.

And therefore we can assume that this is the same ice that we encounter in the world of West Ros. I think that's a safe assumption. Yeah, of course, you might say, well, what if it's not. What if somehow this is an alternate universe or a different planet where another form of ice is the predominant phase. I'm not

sure if that's even a reasonable question to raise though. Anyway, Thompson does a great overview of ice and the physical properties of ice, and I do want to throw in that she has an excellent bit where she weighs in on whiskey stones. Okay, so Robert explained the concept of a whiskey stone. Well, I do not I do not own these, but I assume you do not either. But I've heard of them. I guess I don't. I don't know if I know anyone. I think I might know

one person who has them. But the idea is that you you're such an afficionado of bourbon or whiskey, and you that you don't want anything to dilute it. You want it cold, but you don't want to put some ice in there which will kill the drink but also melt.

So apparently these have been marketed before. The whiskey stones are like our rocks that somebody sells you, rocks that you keep in your freezer, and then when you want to have a cold glass of brown alcohol, you put the cold rock in there, and the rock, of course will not melt and dilute your beverage. Now, if you actually enjoy whiskey stones, no judgment at all, more power

to you. But I would like to point out just real quickly that this is you can get into how it might be a little bit misguided from a physics standpoint, but it's also a little bit misguided, I think from a culinary standpoint, because I mean, I think most people believe that like whiskeys tend to kind of improve with the addition of a small amount of water. So like melting ice cools but also adds water to the drink, And this is an important part of many spirit and

cocktail preparations. And this might be why if you've ever tried to mix a cocktail that is supposed to be shaken with ice, but then you make it without shaking it with ice, it kind of tastes wrong. And that's because one of the ingredients in this cocktail is actually water, and you have left that important ingredient out by not shaking it with ice that dilutes into the drink. Yeah.

I've definitely experienced this making cocktails before, where I'll end up for whatever reason, you know, due to whatever kind of ice I have on hand, I'll end up with a drink that doesn't taste perfect. But once the ice has melted a little bit, it's a different experience totally.

And even with like a straight whiskey on on the rocks, I mean that that's always been my experience of of that, It's like the drink will change as the waking drinking experience will change as the ice melt, which I think is part of the experience. But then again, i'm i'm, i'm, I'm ultimately a novice when it comes to the appreciation of fine whiskeys. But Thompson also makes a physics point

about the whiskey stones. Right right, she writes the following quote, The heat from the soda is used to melt the ice, so the surrounding soda cools off. This is also why whiskey stones are a total sham. Seriously, I can't stress this enough. Don't buy whiskey stones. If you want to keep your drink cold without watering it down, get yourself some water filled plastic ice cubes. They're less stylish but a more useful. Now she continues from here and get

some more detail. What basically her point is that the whiskey stone will only take away enough energy to raise its temperature to the whiskey temperature. An ice cube will take the same energy plus the energy needed to break the molecular bonds which melts the ice. Right That phase transition takes energy the same way that boiling water takes energy, Like, why does your pot of water boiling on the stove not just keep increasing in temperature and until it's the

same temperature as like the heating element below it. Uh, it's because it takes enormous energy to turn that water into steam, and that energy gets boiled off. Yeah. So anyway, that that does directly relate to the building of a giant wall made out of ice, But it was just too interesting in her writing on it was just too humorous to pass over. Well, let's get back to why exactly it is that ice is not a good building material. All right, Well, she points out that quote ice on

a large scale is basically ketch up. So yeah, so, yeah, I sent a large scale is a non Newtonian fluid. In an ice wall or a glacier, the pressure of the structure's own weight causes it to creep, and this would occur even in low temperatures prevented the ice from ever really melting. Dislocation small cracks that cause ice crystals to move over each other would cause the creep even in a you know, a pretty stable, chilly environment. So this would be in play concerning the wall, along with

temperature changes. Yeah, that's right, and creep actually is the technical term there. It comes up in a paper by a chemist that we're gonna look at later in the episode. Yeah, she says that ultimately the wall all she said, the wall would have probably been okay for like a year, but over the course of thousands of years, it would end up being just more of an ice dome or a plateau, depending on the temperature, So it would be far less of an obstacle to certainly intelligent beings looking

to invade the South. Good thing. It's magic then, But but there's more. There's another huge issue and one that's key to the rest of the episode here. Ice tends to have a lot of defects in it due to the way the ice crystals are organized, and this leads to cracks, And of course cracks mean that the ice can ultimately fail, right, It can ultimately lose its structural integrity. And it's not just that the ice fails. All materials can fail, and we have to understand how they fail

and what conditions cause them to fail. But with ice, quote, there's no specific set of conditions that cause ice to fail. Rather, it fails under a wide range of conditions. Yes. Another way of putting this is that ice is structurally unpre addictable. Uh. You take two blocks of ice that are the same size, made of the same water, and one might fail trying to hold up five pounds, while another one can hold

up twenty pounds. And that that kind of difference, that variability is not a good characteristic of a building material. You could almost argue, I think that predictability is more important than strength when you're selecting a building material. Yes. Now, Thompson does point out that there are ways to strengthen the ice, There are ways to make it more dependable, more durable. And the interesting thing is the weird things that you do to ice. Uh. To do this we

find fantastic examples of of this. Not in a fantasy world like a Game of Thrones. Uh. Instead we find these examples in the equally or perhaps even more bizarre world of our own real history. Right. This brings us to the subject of the rest of today's episode, which is going to be this fantastic frozen material real known as pike crete or ice that's about as strong as concrete. Yes, and and again, let me just say that if you're familiar with with this material and it's it's usage and

uh in the project we're going to talk about. Then you know you're in for an exciting time. But if you haven't, just let me assure you that everything is about to get far stranger than a giant wall of ice made to keep undead invaders out. Right, We're more in the realm of a giant tub of ice used to bomb Nazis. But first we're gonna have to take a quick break, but we'll be right back with more ice.

Thank Alright, we're back. So we're gonna be dealing with the Second World War here, a truly global war that worked kind of like a black hole just pulling in I mean, first and foremost human lives, but also human ingenuity and of course funds and resources as well. So there was more than enough room in all of this for the occasional hairbrained scheme to pick up a lot

of steam. And this is one of them. I want to say, I'm not sure exactly how hairbrained it is, Like in some ways it's hair brained, and in other ways it's quite ingenious. It's the strange mixture of of genuine insight and good ideas with proposals so outlandish that they're laughable in their face. Yes, yeah, I I should rephrase. I guess that there are better examples of purely hairbrained schemes that were brought up during War two. This one. I guess it's just more of an idea that this is.

This is a real outside the box idea and one that at least for a while, seemed like it might be the best solution to the problem given the resources at hand and the weight of the circumstances. Right, So, what was the problem that we're going to start with here, Well, the basic problem was the Allied forces needed better aerial coverage of the North Atlantic. Yeah. So to expand on this, I want to refer to a paper that we're going to be consulting extensively for the rest of this episode.

It's called a Description of the Iceberg Aircraft Carrier and the Bearing of the mechanical properties of frozen wood Pulp upon some problems of glacier flow. And this is a report that was presented to a scientific organization called the International Glaciological Society in nineteen forty six, and it was written by a guy named Max Peruts. Now Max Peruts lived from nineteen fourteen until two thousand two. He was an Austrian born chemist and molecular biologist, and generally just

an extremely accomplished scientist. He won the nineteen sixty two Nobel Prize for Chemistry, and this was for his work on the structure of hemoglobin. But Peruts was really just

one of the great pioneers of molecular biology. I was listening to an interview between Brian Cox and the molecular biologist Vincy Rama Krishnan who was talking about Perutss work explaining the structure of proteins, and Rama Krishnan says that in many ways modern biology would be unthinkable without Peruts's contributions. He he did some of the most important pioneering work for the kinds of molecular biology that are you know,

ubiquitous throughout the biology research and biotech world today. But before all this, Peruts was involved in the British war effort during World War Two, and specifically he was working with the ice based technology that we are discussing today, and in this paper he gives a firsthand account of the project and some scientific discoveries that came out of it.

So to to establish the problem. Peruts writes that in the autumn of nineteen forty two, Allied leadership recognized that their war effort was really suffering from a lack of air power range, especially in response to German U boat attacks in the Atlantic, and this was affecting the transport of cargo across the Ocean between Great Britain and their allies in North America. So there's a U boat threat

throughout the ocean. You never know if your your cargo resupply ships are going to be attacked, and you could defend them if you had better air coverage, But how are you going to get planes all the way out there in the middle of the Atlantic where the U boats can attack. That's right, you come down to the limits of aviation technology at that time. Yeah, and Peruts writes, quote it had been a common experience that the carrier based aircraft of the Allies were inferior in armament and

speed to the land based planes of the enemy. And so what he's talking about was that there were aircraft carriers that the Allies had during World War Two, but these aircraft carriers at the time were relatively small, with short runways and limited parking, and storage space. So the kinds of planes that could take off from them tended to have light armor and wings that would like collapse and fold up to make them easier to store. The kinds of planes that were better armored, more powerful, and

could do more damage. For example, I was reading an article by PAULK. Hollands from two thousand two in the magazine Cabinet about this project, and Collins mentioned spitfires and bomber planes as examples of these more powerful planes. Uh, they couldn't fit on or take off from aircraft carriers. They had to be launched from the ground. And this didn't only affect cargo transport and other operations in the Atlantic, it also had implications for future ground invasions of access

occupied areas in say, continental Europe and in Asia. So you know, given the existing limitations on aircraft carriers, if you were to try to land on a distant shore, your airpower inland would be limited until you could capture or establish air fields there from which you could launch these more powerful land based planes like spitfires and bombers

and so peruts, writes quote. It was only natural, therefore, that the proposal for the apparently cheap construction of gigantic aircraft carriers capable of opera rating land based aircraft thousands of miles from their base was seriously considered. So so that's the dilemma there, and they're trying to get more powerful, bigger planes farther out into the ocean, farther from home, right,

and that that's a pretty tall order right there. But then on top of that, now not only does it have to be enormous and also inexpensive, it also would really help if it were essentially torpedo proof, if all these prowling U boats would be incapable of sinking it, right, Yeah, you don't want to load a ship up with all of your most important, most expensive aircraft and then launch it out into the ocean to be sunk by a

U boat. Yeah. So you know, in defensive of everything that comes after this, that is a that's a tall order that really invites outside the box thinking, right, And fortunately we had an outside the box thinker come onto the scene. Yes, enter English journalist turned inventor Jeffrey Pike, who of through nineteen Yeah, and so Paul Collins, writing for that Cabinet magazine article I mentioned from two thousand two.

He quotes The Times of London calling Pike quote one of the most original, if unrecognized figures of the present century. And I just want to read collins brief summary of Pike's early life quote. His career began in nineteen fourteen, when, as a teenager at Cambridge University, he landed a foreign correspondent job by using a false passport to sneak into wartime Germany. After getting tossed into a concentration camp, he

fled the country in a daring daytime escape. In the nineteen twenties, he virtually created progressive elementary education in Great Britain, all for the sake of his own son's education. Pike financed his own school by brilliantly writing futures markets and controlling a quarter of the world's supply of ten employ which brought him to financial ruin in nineteen twenty nine.

He lived on as an eccentric hermit, publishing prescient warnings of Nazism and proposing one of the first media watchdogs. After the war, his freelance genius helped propel the creation of the National Health Service. That's quite a resume. So yeah,

foreign journalists escaped enemy capture. Uh we weird investment portfolio huge Indo ten loses it all eccentric hermit, but then pioneers uh progressive political causes, and Pike was known for having some extremely weird, you could say, outside the box ideas. One that I was just briefly reading about was that in ninety three, as a proposal for for the war effort, Jeffrey Pike got pipe fever and he started thinking, we

need more pipes. We can transport things and people through pipes, and that's way more efficient than trying to transport them just straightforwardly over land and vehicles and all that. So he proposed the idea of transporting goods and soldiers like from ship at shore too deep inside enemy territory through pipes. And obviously this would have some drawbacks, especially when you're

trying to ship people through pipes. But in order to combat claustrophobia and suffocation, the troops that were sent through the pipe could be supplied with barbiturates and oxygen tanks. Wow. Um yeah, that's quite a quite an alternate reality to try and envision, one in which you would have basically

like hot and cold running um armed reinforcements. Right. Yeah, So during World War Two, the British military established an office known as Combined Operations, and this was to coordinate actions that required the cooperation of multiple branches of the armed forces, so if you needed to combine naval and air forces or army, etcetera. And in ninety two the chief of Combined Operations was this guy named Lord Lewis mount Batton. Lord mountain Batton was a big figure in

in twentieth century British history. He's sort of all over the place. But Collins writes that Pike resented himself to mount Batton's Office of Combined Operations and he basically told him, hey, you need to hire me quote, because I'm a man who thinks. And so Pike was thinking, and he came up with an idea a response to this problem of

limited air power range in the Atlantic and elsewhere. That's right in October of Pike said, Hey, why don't we get an iceberg, hollow it out and use that as a floating base, because this would it would float, it would it would be torpedo proof, and it would it would certainly last long enough for us to then establish better land bases, Right, So the idea was that a platform capable of launching bigger, heavier planes like bombers and spitfires could be made out of ice, and and there

were two approaches to this actually, So one is the naturalistic approach, where you just take an existing iceberg and you kind of plane it down and flatten the surface and create a runway. The other would be to create

from scratch a giant barge made of ice. But in general, Pike saw a lot of potential for ice based technology since he claimed that manufacturing ice, even if you're gonna make it yourself, needed only one percent of the energy required to create the same amount of steel, right, which

which I mean that's playing into the energy demands. But also just in general, you have a global war going on, your resources like like steel and even would like those are pretty much all already being contested, you know, like those are needed by to to build airplanes, to to build traditional ships, uh, munitions, et cetera. So if you have a solution that requires less energy and none of the steel that it needs to be used by all these other parts of the war, uh, then you have

a potential, um potentially amazing solution on your hands. Yeah, it would be hugely advantageous if you could make something like this work. And as you already mentioned, ice naturally floats, just automatically floats in water, and this is because it's less than liquid water I think about nine percent less dents. Also, ice is fairly resistant to explosives. They had observed this just through the fact that icebergs that already existed were

surprisingly resilient against shelling by ships. Yeah. I saw that tid that brought up as well, and I didn't I didn't have time to explore further. But of course that just illustrates that warships are firing, or at least we're firing at icebergs just for fun or for before the target target practice if I do well. Yeah, I wonder what the reason was. Why were they just trying it out? Maybe the iceberg was in the form of a lewd

gesture they got kind of offended. Maybe so. And by the way, about the the idea of being resistant to explosives, I believe we're going to come back around to some more specific stats on this later. Ice was believed to be relatively resistant to explosives at the time, but it turns out I think that it's it's more variable than that.

Uh well, one quick thing about ice floating. I have Thompson briefly mentions this like this being a a key attribute of ice because imagine what the shape of life on Earth if ice was heavier than liquid water, If if ice formed at the bottom of the sea, that would make that would just be a disastrous blow to um to life as we know it. Like imagine how organisms would would function or would fail to function in such an environment. Well, yeah, I've read about this before.

Also that the fact that ice floats on water and means that ice forms over the top of say bodies of fresh water that freeze in the in the winter, or even you know, I guess over at the polar ice caps. That protects the water below from continuous freezing and exposure to the elements above. So the fact that that it floats allows life to continue in water in very cold places. And also it means you might be able to make a giant aircraft carrier out of it, exactly. So,

so this is something from Collins here. Uh, Pike's dream became this hypothetical ice based ship that would be known as the HMS Havoc Cook. So I just want to read from Collins a little bit on the size. Here. It would be constructed from quote forty foot blocks of ice. His havocook would be two thousand feet long, three hundred feet wide, with walls forty ft thick. Its interior would

easily accommodate two hundred spitfires. The largest ship then afloat was the HMS Queen Mary, which weighed in at eighty six thousand tons. The havocook would weigh two million tons. That's a big boat. And uh and strangely enough, it looks like leadership kind of went for it. Now, there would be some obvious problems with a boat that size. Uh. I mean, we can get into more of them as

we go on. One of them that was mentioned in Collins article was that, of course you'd have a problem with a boat like this, uh, you know, getting advantage sneaking up on anything. It would probably be kind of slow moving, hard to steep year all of that stuff. But in response to that idea, apparently Pike said, quote, surprise can be obtained from permanence as well as suddenness. I like that. I'm not sure I fully get that, but okay, I'm like halfway there. So anyway, this idea

definitely made it up the chain. Winston Churchill I thought it sounded promising, and according to Peruts in that forty six paper that we referenced earlier, Churchill thought that while it should be a high priority, he also thought that they should quote let nature do the work. Uh So in other words, uh, let's maybe not build something out of ice. Let's see what we can do. Uh we

can do making taking advantage of what's already there. And in this this sounds like a like classic boss thinking, this is a great idea, but let's let's go towards the cheap version of the idea. I like that you brought me the expensive version too, but I really like that cheap version. Yeah, exactly, Let nature do the work. And I've got a great story about Churchill coming up

in a minute. But just to expand on on Pike's thinking, this is a This is a great section from Collins quote in battle, the ice ships could put their onboard refrigeration systems to good use by spraying super cooled water enemy ships icing their hatches shut, clogging their guns, and freezing halfless sailors to death. Oh Man, in this Pike essentially sounds like Mr. Freeze from the sixties Batman TV show. Is it more from the sixties Batman or from Batman

the animated series. I would say it sounds it's either the Arnold Schwartzenegger Mr. Freeze or the the TV show Mr Freeze. I feel like animated. Um. Mr Freeze was like, uh was the ideal balance like that that's my Mr Freeze, that's Freez. Yeah, that that was solid. Whereas if you're doing if you're talking about something ridiculous, you gotta go

sixties or you gotta go Arnold. So Pike presents his idea for a two million ton aircraft carrier made out of ice, and in Churchill is like ice try, you know, the one of the just crazy things about this. First of all, this is not something that just came out, like clearly this is this idea has been public knowledge since uh uh you know at least since since the you know, the nineteen forties, right since forty six when

that paper came out. And yet I feel like any like weird alternate history book or you know that say if it's like, um, you know, the Golden Compass or uh something by Alan Moore. For instance, if someone had said, Oh, I really like this alternate version of reality you've got go in here, but why don't you throw in a giant aircraft carrier made out of ice that also shoots freezing water at other ships. Put that in there, they would say, Now, that's just too far, that's just too silly.

I'm not I'm not trying to create a farce here. That's gonna be in some Kevin Costner movie of the future. It's like in the water World and the Postman tradition. Yeah, or I guess I feel like there there has First of all, there has to be some sci fire fantasy out there that has really latched onto this idea. But

I almost feel like it's such a weird idea. It's got to be the idea you lead with, you know, like everything has to be built around the ice ships of you know, TheBus or whatever the uh your world happens to be. Yeah, And so unfortunately, uh, this idea, as as amazing as it is, ran into some problems in the real world. Yeah. Yeah. Ultimately, the bird Ship never came to be because for for a few different reasons.

One of the big ones though, was that icebergs didn't rise high enough above the waterline and ice flows were too thin. Because that was another idea, Right, you go get some ice flows, cut yourself out, as you know, the the amount that you needed, and use that as the basis for your ship tow them down from the Arctic. Yeah.

And then also further research into you know, the matters concerning the feasibility of constructing an ice based carrier turned up some of the challenges the material, your challenges we've discussed already, Yeah, to go into a little more detail and that. So you mentioned the fact that natural ice just tends to not come out of the water high

enough when it's floating in the water. Peruts talks about how the Fleet Air arm had figured out that in order to have a working aircraft carrier that planes could actually land on and take off from, you gotta you gotta have a freeboard, what's called a freeboard of at least fifteen meters or about fifty feet above the water. And the free board is just the height of a ship stick above the water line. Yeah, if you've ever seen a real aircraft carrier, you'll notice it it rides

pretty high. And this is what you're talking about with ice flows being too thin, like the natural ice flows are just not tall enough, they're not going to do the job. So engineers were given the job of well, okay, we got to construct a man made aircraft carrier platform of ice. But there was a sort of dearth of knowledge about exactly what you could do with ice as a building material. Pre Existing research on the structural properties of ice was sort of all over the place with

its findings. So experiments were carried out in Britain and in Canada to try to sort these claims out. They did a bunch of mechanical strength test results and actually we learned a lot about ice. But part of what they learned is that the way ice responds is in fact highly variable and unpredictable, like the way it responds

to explosives is kind of unpredictable. Sometimes it's kind of resilient, sometimes it gets obliterated, right, and you just you can't just latch onto the results that you like now when you're especially now when you're gonna try and carry out a project like this, right, And so there was another thing they were testing for, which was the modulus of rupture for ice. Uh. This is also known as flexual

strength or bend strength. Imagine a very simple test. Do you have like two supports, and you put a slab of a material on those two supports, and then you put a weight pressing down in the middle between the two supports, and for any given material, you see how much weight a slab of it can sustain of pressure

and Peruts writes that quote. The rich modulus of rupture of ice beams in bending, for instance, was found to be about twenty two point five kilograms per square centimeter, but individual beams sometimes failed at stresses as low as four point nine kilograms per square centimeter, and this is not good. Peruts points out that just regular old pine lumber has a modulus of rupture somewhere around eight hundred kilograms, so way better in general. And again the ice is

somewhat variable. You might get a weak beam of ice here there, and you wouldn't even know it until you press on it. Right, If you if you're gonna do if you're gonna build something out of this, if you're gonna design something built out of this this material, you need to know how far you can push it, and it needs to be at least you know a dependable range and not just a roll of the dice exactly. So ice is just really not sound as a large

load bearing building material. And so this leaves us around February of ninette with ice looking like a bad candidate to build an aircraft carry y're out of That's right. Things look pretty bleak, at least until they read the work of Herman Mark and Walter P. Hollenstein. Yeah. These

guys were working out of Brooklyn Polytechnic. Yeah, and they've been experimenting with frozen water with wood pulp inside it, and they found that this the resulting material like this, essentially a mixture of frozen water and wood pulp, was stronger than ice, significantly stronger. Apparently Herman Mark had formerly been Peruts's teacher at some point, and I found an account of the discovery written by Peruts and quoted in a piece for Chemistry World by Kit Chapman. Uh so

these are Peruits's words. Quote. Pike handed me a report that he said he had found hard to understand. It was by Herman Mark, my former professor of physical chemistry. As an expert on plastics, he knew that many of them were brittle when pure, but could be toughened by embedding fibers such as cellulose in them, just as concrete

can be reinforced with steel wires. Mark and his assistant stirred a little cotton wool or would pulp the raw material of newsprint into water before they froze it, and found that these editions strengthened the ice dramatically. And I love this comparison to actual building practices such as embedding rebars steal wires within concrete. When you're making a building, the fibers or wires running longitudinally through the material help

prevent rupture. But so this stuff, this mixture of frozen water and would pulp, would come to be known as pike wrete in honor of Jeffrey Pike, a k a.

Pike's Concrete. And there's an anecdote about the discovery of this material and trying to sell it up the chain that Collins reports, and he gets it from the book Pike the Unknown Genius, published by Evans Brothers in London in nineteen fifty nine, biography of Jeffrey Pike written by David Lampey, and the story goes like this, So one day Prime Minister Winston Churchill gets a visit from Lord mount Batton while while Churchill is at the Prime Minister's

country house known as Checkers, and reportedly when mount Batton arrived at the house, the staff informed him that the Prime Minister was in the bath. You know, he can't talk right now. He's he's having a good scrub. And Mount Batton was like, good, perfect, take me to him. So Mount Baton charged into the bathroom. And then from here, I'm going to read from Collins version of the account quote, I have Mount Batton explained a block of new material

that I would like to put in your bath. Mount Batton opened his parcel and dropped its contents between the Prime Minister's bare legs in the water. It was a chunk of ice. Rather than bellow at his Chief of Combined Operations, Churchill stared at the ice intently, and so standing by the bathtub did Mount Batton himself. Minutes passed and they still looked into the steaming depths of bathwater before them. The ice was not melting. This is such

a great moment in in in global history right here. Um, I mean it all and almost and certainly it has to be up there for like great, great nude moments in world history. You know, I'm just dealing with, say like that the non saucy moments in world history that mattered that also combined involved nudity, Like this has to be a naked Churchill in his bath beholding this, uh this, this floating block of wonder ice. Well, I'm not sure

he was naked. Maybe Churchill bathed in a tuxedo with tales on the top hat you Well, maybe, but then we're just in a weirder territory. But so yeah, here here we have pike crete. And I should say that I'm a little confused about the timeline here because some sources I was looking at report that the pike crete thing came in like early nineteen forty three, but Collins

puts this story in late nineteen forty two. So there might be some questions about the timeline here, and and and so I do wonder about the veracity of the story, but I have no reason to believe that it's fabricated, and I want to believe it's true. Well, and I don't want to dispel this mental image. So we're gonna take a quick break. Keep this in your head, and then after a word from our sponsors, we will return

and bust open the pike cretan. Alright, we're back. So here we are at the birth of pike create the potential solution to the iceberg aircraft carrier problem. That's right. They realized that this was an avenue forward. This was a way we might be able to strengthen the ice so that we could do all the amazing things that we want to do with it. So they experimented. Different

pulp ice combinations were tried. You know, they are different pulps, would pulp, rocks, other materials put in there, but they ultimately found that all you needed was as little as four percent pulp and you would experience a huge upgrade endurability compared to regular ice. Basically, these embedded materials prevented cracks in the ice from advancing. So I mean basically

you could think of it as um um. You know, a crack starts and instead of being able to eventually vein its way through an entire block and bring it to pieces, it could only go so far um before it encountered something to stop it. So if you were going to make a wall out of ice, pike crete would be a better candidate than regular ice. Yes, yes, s Thompson points out, it's not that it would make it. It makes it more durable, and it doesn't mean that

it would be invincible. It would still fail, but it would fail in a much more predictable fashion. And and that's also why Thompson ultimately points out that if your brand, the builder brand, in the Builder the legendary brand, if you're looking to build a giant wall of ice, even with the help of some magical beings, uh, doing something like pike crete would be your best option for building

that wall. Yeah. So I was reading Perutz's reports about these experiments with pike crete about like the optimal type of wood pulp to use, the optimal amount of wood pulp suspension of water to use. So it looks like they usually ended up using spruce or pine wood pulp that's ground up by machines. And this is the pulp that ultimately would become the pages of a newspaper in

another context. Uh. And then when in liquid form, this this mixture has interesting properties, like a five percent suspension is sort of porridge like, it's kind of like oatmeal. But I tend to fifteen percent suspension is more like a sponge, and when you freeze it, you yeah, you get this resulting matrix of water, ice and saturated wood fiber that becomes extremely tough. You can bash it, shoot it.

It tends to hold together very well. There's a famous story of Lord mount Batton taking out his pistol at a meeting of Allied commanders to shoot a block of ice. Of course, when he shoots the block of ice, it shatters all over the place, and then shoot a block of pi crete to demonstrate the difference. And apparently when he shot the pike crete, the bullet ricochet and graze the pant leg of an American admiral in the room. Oh my goodness. There are also reports that the people

outside heard the shooting. They had not been warned, and they were like, who's shooting in there? Is there an assassination going on? But no, it's just just dashing Lord Mountbatton with his pistol shooting it materials to to make a point. Wow, this just said, this is so weird, and it's again, I don't think it has ever been

in a in a film. I had a I had a Russian history professor wants who who was fond of pointing out that you know, you'll see some movies about um, for instance, the Eastern Front during World War Two, but you're always going to see the same stories, the same particular stories told time and time again. When when there's so many additional uh, you know, it's equally interesting and in many times strange stories that are spread out across

that entire theater of the war. UM And and likewise, when you look at like all the things that are going on during this period, you have you have stuff like this that just for some reason has a way of falling through the cracks. Yeah, totally, and and it still keeps getting weirder. Is another thing about this project is that it had to be very secretive. I mean, this is this is top secret military research at the time. So you had people making just big troughs and buckets

of wood pulp mixed with water. And this is like the same level of secrecy where the as where people are trying to create a death ray or something. Uh. They apparently they took out refrigerated rooms under a London

meat market, I think it was Smithfield's market. They converted this into this top secret experimentation in manufacturing space for PI crete, and Perut says that a lot of people working on PI crete research had no idea what this was going to be used for, Like they were kept in the dark in order to maintain you know, ops seck. But a few of the things they determined in their research. One was that an ideal amount of wood pulp to make PI crete it's about fourteen percent, so you know,

like eighty six percent water fourteen percent wood pulp. Uh. They also found that temperature can matter a lot this material. A lot of the good things about it become less reliable as it warms up, and so in order for it to have its optimal features, it really needs to be kept at about negative fifteen degrees celsius. But if you keep it cold, it is much stronger than regular ice.

It behaves much more predictably than regular water ice. Karu says that it gave results which were reproducible to within about plus or minus, and the wood pulp actually decreased the brittle nous of ice so much that Peruit says that PI crete was ductal and could even be machined on a lathe. So ductle means that it can be stretched out into a wire, so that that's definitely showing you a material that is tough and not brittle. So he said, we come back around to just how torpedo

proof pie crete would be. Uh. In researching this, they found that a torpedo would upon impact dig in about sixty centimeters and then he would, um, he would radar out a four point five meter area in the pike creet. So they figured, okay, we would need to have a nine meter thick hole that would do the work. Um and then of course also to accommodate the aircraft, as I think we already mentioned, it would need to be like six long and sixty wide, so huge again, yeah, enormous.

So basically this is this is the sort of durability that would prevent a U boat from being able to like sneak in, pop off a torpedo and just bring the whole thing down, right, it was it was supposed to be sort of like a floating fortress or a floating island. It would just be for practical purposes invulnerable, yes, but that doesn't mean it was without problems. So like, one of the things that they observed while they were testing the material properties of PI crete was that PI

crete is like other ice, subject to something we mentioned earlier. Creep. Yes, creep is again the slow deformation of materials under pressure over time, the slow flow. So if you put a heavy load on a slab of pike crete, it's not nearly as susceptible to cracking and rupture as regular ices. But if you just leave that load there, the slab will probably sag over time, which is not something you want to happen if you're going to be parking aircraft

on it and stuff like that. So research revealed times and periods of creep were different for different substances, depending on you know, the kind of wood pulp, different percent suspensions and all that. But the temperature constraint was again very important they need. They determined that negative fifteen degrees celsius was like the highest permissible working temperature. If it gets warmer than that, this boat is going to be

in trouble. Okay. So eventually in ninety three the naval engineers decided, yes, pike rete is strong enough, we can make this. We can do it, so get to work

constructing our berg ship. Uh Peruts reports that they wanted to have a working prototype that would be ready within the next winter season, and then soon after that a fleet of them which would be ready for a possible invasion of Japan and uh Peruts notes that too many engineers this seemed impossible, but then he puts it within the context of the whole sort of like war orientation, and Peruts writes, quote in retrospect, this may seem the

obvious verdicts, but it must be remembered that the Berkship plan was only one of several apparently impossible engineering feats conceived during during the war e g. The atomic bomb, and that the question was not so much one of absolute feasibility, but rather of whether the ultimate strategic advantages to be gained by the burg ships were in proportion to the expenditure of manpower and materials involved in their construction.

In fact, I think that had not the course of the war and the state of our armaments changed, the birdship could have been constructed. So that's Peruts's opinion. He thinks, you know, if if things hadn't changed made it not so rewarding, we could have done it. Just a couple more physical details about the proposal that I thought were very interesting. One is that this hypothetical giant bird ship would have had a waterproof skin on the outside to

help insulate the pike crete. But then also the material would have to be cooled with artificial refrigeration, right, because they've got to keep it at negative fifteen degrees celsius or colder. So they would have an air conditioning system on the aircraft carrier made of pike create to refrigerate the pike create, and it would be blowing compressed air

on it to keep it cold. But the downside is if you think about that, oh man, if the air conditioning system breaks, then your ship could start melting and lose structural integrity. Though another good thing about pike Create, as we mentioned earlier, is that it melts more slowly than regular ice, so you'd still have a bigger window

of time than you would on a regular iceberg. I can't help but be reminded of the old There was an old Disney cartoon with like Donald Duck and the nephews battling each other, you know, like an epic snowball fight.

Do you remember this one? Yeah, yeah, yeah, And Donald Duck I believe builds like a warship out of ice, and it is He's you know, devastating his nephews until they they like they have like a flaming bow and arrow, which seems a little violent in retrospect, but they fired that into his ice ship and then melt it and

it like melts into the shape of like a duck skull. Brutal. Yeah, it's it's weird stuff, okay, But a couple more questions about this aircraft carrier, Like if you're going to take this idea seriously and try to actually build it, first of all, where do you freeze it? Uh? You know, remember that Winston Churchill wanted to let nature do the job. That was his quote, That was the cheap boss idea. But it quickly became apparent that this was just not

really feasible. There was just nowhere they could find on Earth where you could you could feasibly let natural cold freeze this thing in place. It just wasn't gonna work. So instead they turned to some artificial construction ideas that would be based in Canada perots rights quote. The locality eventually selected for building the prototype was corner Brook in Newfoundland where I said it right this time? Did yeah? And uh? And I but I was more reacting to

the fact that I've been to Corner Brook. I barely remember it that I was a child at the time, but yeah, I've been to Corner Brook. Oh what's it like? Okay, I think I think I got to get a toy at a gas station or something there like. That's of course the only thing I remember because I was a child. But I remember the name. Well. It sounds lovely and it sounds cold, because Perutz said the the average daily

temperature was negative five degrees celsius. I guess this would be in the winter time, but it could be expected for a hundred days straight and there you would have protected waters of sufficient depth in order to try to build one of these things now. Paruts also says, you know, even though it wasn't made of steel and didn't require steel like like a regular warship would, it is still a huge material and investment. One ship alone would require

one point seven million tons of pi crete material. Where can you make that much? Peruts argues that this alone would have worked whired a refrigerated plant of something like a hundred acres or forty hectares, and this would take away from other industrial needs of the Allied war effort. Yeah, you can't build that out of ice. You're right to build that out of out of metal and wood, right, Yes.

And so these difficulties we've been talking about, along with other changing circumstances, ultimately caused the Allies to abandon the plan for berd ships in nineteen forty four. Uh. And the other circumstances were a range of things. One was that there was that airplanes themselves started to get increasing flight range. Yeah. I just our aviation technology increased enough to where suddenly those um, uh, those distances weren't insurmountle anymore. Yeah.

And Paruts actually says that, Uh, it's I guess a lot of these changes started around nineteen forty two, at the same time this project started. But eventually you could get land based airplanes out far enough over the ocean to provide sufficient air cover even even if they had to launch from from bases on land. And other things

were the acquiring of additional bases on land. So like a couple of sources mentioned the fact that Portugal granted the Allies use of the Azores in the Atlantic, and this helped helped them reach farther out into the ocean. So there's that on the one hand, and then on the other hand, some changes in airplanes also meant that you needed even more runway space than you had before.

So it would mean that you could build this six hundred meter long floating runway, make this huge investment to build this thing, and then a lot of the new planes that you want to launch can't even get off of it because now that's not long enough for them. They've just got to be launched from the ground still, So as you're accommodating what kind of platform you can get out into the middle of the ocean, the planes

are requiring more and more platform all the time. Finally, Peruts also notes that quote the island hopping campaign of the American forces in the Pacific had been six tessful beyond expectation and had made an eventual invasion of Japan appear feasible without large floating air bases. So just in general, in this short amount of time, the world had moved

on and was leaving the idea of the birdship behind it. Right, So we never got to find out if this idea could really be achieved because it just it just sort of became obsolete as the war progressed. But there's an interesting note that that Peruts makes about this project as

a contribution to ice science in general. He writes, quote, Nevertheless, the volume of first rate data produced within a period of six months in this country and in Canada under the pressure of war far exceeded the total volume of reliable work that had been done before on the mechanical properties of ice itself. So war, what is it good for? Um? Well, I still think the song is correct. Absolutely nothing. But I guess you could make an argument for the advancement

of of our understanding of ice. Well, it may makes you wonder, like, what if we just put the amount of priorities on regular scientific research that we put that we put on that research when it's necessary to win a war. Yeah? Absolutely, Um. I remember Neil de grasse

Tyson making this point about about space exploration. He was fore which book this was, But he's basically saying, hey, you know, if we really want to get serious about about space exploration, we need to fake the existence of an extraterrestrial enemy, because that if we can get the war machine behind it. If that well, if we can get that kind of political and public capital, uh supporting it, you know, then we could do all sorts of things. Um. Unfortunately,

in a way, I kind of agree. I guess this is the assymandias theory from Watchman, right, But um, but I think part of the problem is a lot of what you would end up researching was the creation of newer, more powerful weapons, which are maybe not exactly what we need. Right. I think we've discussed this before in terms of of

of rocket science under the Third Reich. You know, there's there's often this uh, sort of fantastic misconception that there is you know, there's these great advancements in space technology, and there's oh there was a secret moon base that the Nazis had, that sort of thing that the Nazi space program. But and really you do, and of course you did have a lot of of of brilliant minds working at the time. But like so many other brilliant minds during this global war, they were sucked into that

black hole of global conflict. So their value to these nations that they were, um, they were serving. We're we're just boiled down to warfare interests like oh, you're good at rocketry, Well, can you make a rocket bring death to this country? Oh? You you you know about how ice works? Well, that's great because we're trying to build a massive weapon out of it that sort of thing. Yeah, totally. I mean, you know, we don't want to downplay that.

Like in in Germany there were actually advances made in rocketry that were later put to peaceful uses, but the uses they were put to, primarily during the war, were to rain held down on England and other allies. But so anyway, that's the end of the historical pike crete story. You know that that the project came to an end, and there has not been a lot of serious investigation

of pi crete at certainly not at that scale. Since then, people have done little projects where people have built structures out of pike crete and stuff, and and that's interesting. And in fact there have even been like like MythBusters and some other TV shows kind of like this. I think there's one in in Britain called Bang Goes the Theory that have tested out small boats made of pike crete.

I know in the MythBusters episode they tested the mechanical properties of pi crete, like trying to drop it from certain heights and smash it, and they confirmed the kind of stuff that pruits had already been saying that like a frozen block of water saturated wood pulp did indeed melt a lot more slowly than an equivalent sized block of water ice. It was also a lot more structurally sound when when dropped from a height of about six ft, a frozen block of water would, you know, shatter into

a million pieces, just like you would expect. But a block of frozen pie crete would break, maybe in half, maybe lose a piece here and there, but it was not nearly as brittle as the water ice alone. And then in the MythBusters investigation, they actually make something they end up calling super pi crete, which is, instead of using wood pulp in its you know, very small shaved up form, they use whole sheets of newspaper frozen within the ice. And the sheet newspaper pike create was super strong.

It was extremely resistant to shattering. Oh man, I have you used a newspaper that has really strong journalistic integrity. It's going to hold up even more. One other just sort of popular media thing I came across was that there is a YouTube channel called the Hydraulic Press Channel. Have you ever watched this? No? But I'm assuming it's it's like the old David Letterman bit, right, where the where he would take different things and put it in

a hydraulic press. Okay, it's exactly that. It's just something, Okay, excellent. I did not know that was a David Letterman thing. Yes, oh yeah, it's like the old David Letterman show. They would do that. Yeah, that's great television. And I gotta admit, you know, I start one of these videos up, I'm probably gonna watch it to the end. I just I want to see what it looks like. So yeah, then you know why again it's James Cameron's fall because of

Terminator one. Yes, as children, we watched that scene where the eight hundred is crushed in the hydraulic press, and it made an impact on it. It burned into our psyche, and there's just something about a hydraulic press we can't look away. Yeah, So the hydraulic press channel they tested out some PI crete, regular sawdust PI crete, and they found, of course, it does not shatter the way you would

expect ice to shatter. Instead, I would say that it seems to under extreme pressure, it seems to first kind of melt around the edges and then crumble ultimately, I mean, under much more pressure than it takes to crush a similar amount of ice. It ultimately kind of crumbles in a sticky looking way, kind of like a crumbly block

of feta cheese. Can you picture this? Yes, they can picture something that looks like a cross between crumbly feta cheese and maybe like orange juice concentrate, And so it's just kind of peeling off in pieces like that. They also they also try some newspaper mush pike crete. This this does also kind of a melt and a sticky crumble. The pieces are softer, less frozen, and then they end up using what looks to me like toilet paper. I'm not sure they call it sheet paper, but this one's

got a really interesting texture. It's worth looking up. It kind of flakes when crushed, and the flakes are still they demonstrate very large and strong, so it it looks like something that would be soft and melt in your hand, like a piece of butter or cheese. But then when you pick it up it's like solid. You can bang it against stuff anyway. Very interesting material and something that I think you can quite easily make or make a

version of at home. That's right, I mean, ultimately people can make their own pie create at home after listening to this show and then tell us about how it went.

And there was a thing in that Cabinet magazine article by Paul Collins where he quotes a professor, a professor named Erlin Schulson, director of the Ice Research Laboratory at Dartmouth College, and Schulson uh is trying to answer the question of why modern people don't make better use of pie crete in the light of its benefits, and he just says, I don't really know why it has languished in obscurity. It seems like something that could actually be useful for a lot of things, but for some reason,

nobody's not nobody. I mean, people have done things here and there, but it does not seem like it has been taken up in a in a large way. So that's the past and the present. We might well wonder about the future of ice based building. And Uh I was looking around a little on this and I ran across um the Uses of Martian ice papered by Charles su Cockle, published in the Interdisciplinary Science Reviews. This was

back in two thousand four. Uh Cockle rights quote Martian polar ices could be used as a shield by human explorers. By covering a research station with ice, high energy solar particles could be absorbed, protecting explorers from potentially damaging radiation exposure. Finally, martian ices provide a substratum over which scientific and exploratory expeditions could traverse on their way to deep field sites

and the geographic poles themselves. Martian polar ices have the potential to open a new and unique chapter in the long relationship between humans and ice. So that's a neat idea, like the idea of building structures out of ice, and it sounds like like highways of ice on the Red planet. Sure, and I think this has been proposed by other people

in the past. Uh I can't remember where, but I know I've encountered the idea of using ice or even a mixed up matrix of of ice and and other fibers kind of like PI crete to build structures potentially on on like asteroid surfaces. Yeah, so there may be some potential for for PI create there. Um. I was looking around for some more takes on this, and uh I came across an interesting concept, the Mars ice House project, which is a concept at one at the two fifteen,

New York makers fair. They have a really sleek website at Mars ice house dot com. But this is a concept from from Search that's uh, the Space Exploration, Space Exploration Architecture and clouds AO that's Clouds Architecture Office, and it basically the ideas too is to have robotic machines three D printing buildings and structures out of ice on

the Martian surface. And they claim that quote in consultation with our team's expert scientific advisors, astrophysicist, geologists, structural engineers, and renowned three D printing experts, we have achieved positive experimentation with one to one and ice printing and successfully analyzed structural models. Now, obviously there are a lot of caveats here related both to the properties of ice and the particular challenges of the Martian environment. But I think

it's really really a thought provoking concept. You know, imagine ghost cities made out of ice built on Mars by autonomous laborers yea, or robots build structures that nobody's in yet. I like it, yeah, yeah, just like weird like geometric egglue cities on Mars. And I had and I don't know that they really get into the pie creek concept as much, but it makes sense that that could be a part of it as well. I think part of the secret to this is don't let Kohagen buy up

that city. He can't get in early because he's not going to give the people to air. That's true, He's he is stingy with the air. But the ice up for grabs, I guess all right. So there you have it, pie crete, ice, walls of ice. I hope you enjoyed this journey. It was a fun one to go on with you, and as always, we'd love to hear from you. Do you have thoughts on on ice itself? On pie crete?

Have you ever made pie crete? Uh? Do you just have any feedback on the various um contemplations regarding like eighties and nineties cinema that we have touched on. Uh? You know how to get in touch with this? Joe will provide the details here in a second um. As always, if you want to listen to other episodes of Stuff to blow your mind, you know where to find us. Wherever you get your podcast. There a million places to

get us out there. All we ask in return is that if you have the ability to rate, review, and subscribe. Do that because that helps us out huge Thanks as always to our excellent audio producer, Seth Nicholas Johnson. If you would like to get in touch with us with feedback on this episode or any other, to suggest a topic for the future, or just to say hi, you can email us at contact at stuff to Blow your Mind dot com. Stuff to Blow Your Mind is production

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