Project Habbakuk: Britain’s ice “bergship” aircraft carrier project (2017)

https://99percentinvisible.org/article/project-habbakuk-britains-secret-ice-bergship-aircraft-carrier-project/

by not_a_boat • 2 years ago

143 49 2 years ago

akarve• 2 years ago

This is one of those “so cool yet so silly” brainstorms that I’m grateful someone was audacious enough to entertain. I’m both relieved and saddened that it never came to fruition.

There’s a word, chindogu, to describe things that are less than useless. In some sense this project engendered more problems than it solved. Like so many other attractive brainstorms.

euroderf2• 2 years ago

It's probably worth the trouble to try making some DIY pykrete.

Take a chain saw to it. Take a sledgehammer to it.

dmurray• 2 years ago

Unsurprisingly, Mythbusters have tried it - not at the scale of an aircraft carrier, but a boat displacing a few tons:

euroderf2• 2 years ago

"Some leaks sprang here and there, but a few sprays from carbon-dioxide fire extinguishers sealed them pretty well, at least for a little while."

Excellent!

zoeysmithe• 2 years ago

Pykrete is one of those things that makes sense in theory, but in practice and from a practical perspective just isn't great.

There aren't a lot of places in nature where you have tons of trees and easy to get ice. So a society would never default to pykrete because those two things tend to be the opposite of each other. Its a somewhat unnatural thing to do.

Industrialized societies just can make steel and steel doesnt start to soften until 500-600 degrees F. There's no need for a 24/7 refrigerator power plant to keep steel from melting. Steel also is strong and rigid. Steel is of course still used today for both war and civil ships, and has been since the day it became technically and economically feasible to do. Its really hard to beat steel. This project has some nice technical merits and pykrete itself is interesting, but it just doesnt seem to ever have a practical use.

RugnirViking• 2 years ago

There aren't a lot of places in nature where you have tons of trees and easy to get ice.

I take issue with this - there are vast swathes of canada, sibera, and northern europe where this is the case. I would say however finding all three year-round near liquid water may be harder, although not exactly an insurmountable challenge compared to say, moving quarried rock 5 miles to build a house

philwelch• 2 years ago

This reminds me of my favorite part of this story. In 1943, the first Quebec Conference between the US and UK military brass was a very contentious and heated affair, with the top generals and admirals on either side almost coming to blows. At one point they all dismiss their aides and go into a closed session, and Lord Mountbatten takes this opportunity to brief everyone on Project Habbakuk, using some samples of pykrete to demonstrate its resilience compared to ordinary sea ice. At one point in the demonstration, he draws his service revolver and fires at the pykrete.

Now, both the US and UK aides and staff officers are outside the room where this is happening, and they don’t know what’s going on, but they all remember how heated the earlier discussions were, so naturally, when they start to hear gunshots from inside the room, they all panic and assume the worst and burst through the door. Fortunately, everyone was unharmed—the bullet ricocheted off the pykrete and embedded itself into the wall, only grazing the trouser leg of Ernest King.

renewiltord• 2 years ago

I believe they didn't actually use pykrete in the Canadian test model. It was just ice.

pfdietz5• 2 years ago

The outcome of this project is an illustration of a rule of thumb from materials science: many solid materials begin to lose their mechanical properties at about half their absolute melting point. This is why (for example) ordinary steel should not be used above about 550 C; there's too much creep.

kjellsbells• 2 years ago

Can you expand on this comment in the context of ice/water? It implies ice changes behavior at about 140K, but that isnt close to a phase change boundary, so what would you expect to be seeing here?

SideburnsOfDoom2• 2 years ago

At a guess, movement like that seen in glaciers and ice sheets?

denotational• 2 years ago

The glass transition temperature of amorphous ice is approximately 140 K.

0x457• 2 years ago

This is that how jet fuel melted steel beams?

afterburner• 2 years ago

Not melt, soften slightly

SideburnsOfDoom2• 2 years ago

Here's a blacksmith demonstrating this exactly: https://www.youtube.com/watch?v=FzF1KySHmUA

dboreham• 2 years ago

Well there goes that conspiracy theory..

kimixa• 2 years ago

I thought the "failed" result of the project was more due to economic factors, and the reduced need due to other actions in the war meaning a waterborne carrier was less useful. Not some issue with the mechanical properties of pykrete. If the tested properties were already past that 1/2 absolute temperature point and considered acceptable, it doesn't really matter what the behavior would have been at less than that.

Did I read it wrong?

alexwasserman• 2 years ago

Also what looks like insane scope creep.

"The full-sized ship would also need to have a range of 7,000 miles, support heavy bombers and be torpedo-proof. It was to be over a mile in length, weigh as much as 2.2 million tons and require as many as 26 electric motors to move and steer across the ocean."

That's a crazy target growing out of "cheap to produce aircraft carrier"

pfdietz5• 2 years ago

As I understand it, they found out they needed to refrigerate the ice to keep it from creeping too much, and this increased the cost too much for the idea to work.

The US did make some vessels out of concrete because of constraints on steel production. A famous example was a barge in the Pacific (I think at Ulithi?) that was devoted to making ice cream.

grecy• 2 years ago

Also same with cold . Up north it’s a fools errand to run heavy machinery past about -55c. The steel develops tiny fractures, and six months later the ten ton loader will just break in half.

Most stop as it approaches -50c

KineticLensman3• 2 years ago

Check out Hobart's Funnies [0] and the great Panjandrum [1] for some other awesome WW2 British out-of-the-box thinking.

[0] https://en.wikipedia.org/wiki/Hobart%27s_Funnies

[1] https://en.wikipedia.org/wiki/Panjandrum

Theodores• 2 years ago

This concept could be done today with newer materials such as mylar film and polystyrene to keep the sun at bay.

Although a YouTuber would be able to do it for internet likes, in reality, when the horse manure gets real, every aircraft carrier is a dead duck when the enemy has hypersonic missiles.

office_drone• 2 years ago

they called it Project Habbakuk, in reference to ... "I am working a work in your days, which ye will not believe though it be told you."

This is a slightly more subtle way of calling it Project You Ain't Gonna Believe This

quartesixte• 2 years ago

How many regular mass attending, God fearing Anglicans could even recognize on the spot the minor prophet Habbakuk?

Bizarre project all around.

davidwritesbugs• 2 years ago

Every war should have a role for the Panjandrum.

FrustratedMonky• 2 years ago

Think most peoples gut reaction would be that it would melt.

But

"it took three hot Canadian summers for the test vessel to completely melt."

Seems like in north sea, it would have worked and probably would have happened if it wasn't for un-related changes like airfields and re-fulling planes.

msarrel• 2 years ago

It was either going to be ice or concrete https://warfarehistorynetwork.com/article/the-concrete-fleet...

wizzwizz4• 2 years ago

The material they used (water mixed with wood, frozen) is called pykrete.

Blocks of ice containing as little as four percent wood pulp were weight for weight as strong as concrete; in honor of the originator of the project, we called this reinforced ice "pykrete". When we fired a rifle bullet into an upright block of pure ice two feet square and one foot thick, the block shattered; in pykrete the bullet made a little crater and was embedded without doing any damage. My stock rose, but no one would tell me what pykrete was needed for, except that it was for Project Habakkuk.

(from I Wish I'd Made You Angry Earlier by Max Perutz, via Wikipedia: https://en.wikipedia.org/wiki/Pykrete)

TylerE2• 2 years ago

Unfortunately it turned out to be basically impossible to keep a ship-sized block of it frozen, and modern attempts at replicating it have found the strength claims to be a bit "optimistic".

FrojoS• 2 years ago

This could be straight out of the Command and Conquer: Red Alert series. [1] https://en.wikipedia.org/wiki/Command_%26_Conquer:_Red_Alert

elwell• 2 years ago

Can't get sunk by an iceberg if you are an iceberg. taps side of head

meeks2• 2 years ago

What if, instead of building a full carrier out of pykrete, you instead build very simple pykrete ships that follow around the outside of a carrier group to add a layer of protection from torpedoes and sea drones?

WorkerBee28474• 2 years ago

From https://www.usni.org/magazines/naval-history-magazine/2020/a...

By definition, a convoy consisted of two or more merchant ships under the escort of one or more warships, but typical transatlantic convoys during the war consisted of large numbers of ships—the largest composed of 166, with typical convoys consisting of 45 to 60 ships—steaming in 9 to 12 columns with 1,000 yards between columns and 600 yards between ships in the individual columns. Because of their extra vulnerability, tankers and ammunition ships were placed in the innermost columns, and the convoy commodore in charge would be in the lead ship in the center column.

That is a lot of attack surface. But they kind of already do your idea, just with metal ships carrying goods.

meeks2• 2 years ago

Yeah makes sense, if you already have metal ships carrying goods there is no need to make additional ships just for protection. I suppose there could be an economic advantage if the pykrete ships can be made significantly cheaper and faster than the cargo ships.

It makes me wonder why Ukraine is so successful in the black sea with their sea drones vs. the Russian navy? Why wouldn't Russia have ships or something else blocking their battleships at port? It seems Ukraine is able to sink everything with ease at the moment.

Yeul• 2 years ago

If memory serves there was a plan to invade the Azores in WW2 which would have been immensely ironic.

After WW2 the US was gracefully handed over a few islands to serve as aircraft bases. The Chinese still lack such soft power so they have to make their own islands.

Qem• 2 years ago

That makes me wonder if that guy that was killed by his girlfriend while attempting a dumb stunt, using a encyclopedia as ballistic shield, would succeed if he had soaked the book in water and put it in the freezer overnight, beforehand: https://www.dailymail.co.uk/news/article-5878953/Prosecutors...

tomcam• 2 years ago

He just had to use the same book twice. He ran several successful tests but with different books.

Project Habbakuk: Britain’s ice “bergship” aircraft carrier project (2017)

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