Project Habbakuk: Britain’s ice “bergship” aircraft carrier project (2017)
99percentinvisible.org
99percentinvisible.org
"Strength loss for steel is generally accepted to begin at about 300°C and increases rapidly after 400°C. By 550°C steel retains approximately 60% of its room temperature yield strength, and 45% of its stiffness. At high temperatures, steel is also subjected to significant thermal elongation, which may lead to adverse impacts, especially if it is restrained."
At 800 C ("dull cherry red"), the yield strength is down ~90%: https://www.steelconstruction.info/images/9/99/Steel_strengt...
This is talking about short term properties of steel, which would be important in building fires, but creep also increases with temperature.
Did I read it wrong?
"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"
Sailing midway all the way!
For starters aircraft carriers face into the wind for takeoff and landing. So that means either engines for maneuvering (noted in the article) or support vessels. Presumably support vessels are vulnerable so not in the picture.
It would sail like a pig ‐ with 90% underwater it'll pretty much go where the current goes. And very slowly.
I imagine the engines would either be small (slow maneuvering) or large (need fuel etc).
Once you need significant fuel you need to store it. Plus of course all the men, and their stores. And a lot of this doesn't like freezing temperatures.
To be useful the thing presumably has to be far from land, presumably closer to the enemy. So the enemy deploys a bunch of anti-aircraft ships to basically follow the thing. Returning aircraft are sitting ducks.
I'm no mechanical engineer, but none of this makes any sense to me at all.
I'm even less an admiral or air marshall but I dont see any tactical or strategic advantage here either.
Not disagreeing with your main points at all, but from a strat/tac point of view, up until later in the war, there was an air gap in the Atlantic where German U-Boats didn't have to worry about a significant air threat from the Allies. A large airfield parked mid-Atlantic might have significantly improved Allied air coverage, and helped reduce the stunningly bad shipping losses they were experiencing.
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.
Most stop as it approaches -50c
This is a slightly more subtle way of calling it Project You Ain't Gonna Believe This
Bizarre project all around.
> 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)
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.
Take a chain saw to it. Take a sledgehammer to it.
Excellent!
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.
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
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.
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.
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.
> 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.
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.
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.