Live data from Hacker News

Why wood pulp is world's new wonder material

newscientist.com

1–10 of 55 posts

Re: Why wood pulp is world's new wonder material

#2
This brief article about current uses of wood pulp reminded me of something I read in a book back in the 1970s about a proposal to build an aircraft carrier during World War II (when there was a shortage of steel) out of a mixture of wood pulp and water ice. That material was called "pykrete," after the name of its inventor, Geoffrey Pyke. The shortage of steel was alleviated, and plenty of aircraft carriers constructed of conventional steel, before this idea was implemented. In actual use, such a ship would have had to have been continuously refrigerated, perhaps a greater drain on scarce materials than building a ship out of steel.

Sure enough, there is a Wikipedia article about the material,

http://en.wikipedia.org/wiki/Pykrete

which reports that the Discovery Channel popular science program Mythbusters made ship models to test out the idea.

Wikipedia

http://en.wikipedia.org/wiki/Project_Habakkuk

and the Royal Naval Museum

http://www.royalnavalmuseum.org/info_sheets_Habbakkuk.htm

have websites about the frozen aircraft carrier project that relate more details, citing sources other than the book I read decades ago.

AFTER EDIT: I think the book I read about this plan was Of Spies and Strategems by Stanley Lovell,

http://www.amazon.com/Spies-Stratagems-Stanley-Lovell/dp/B00...

although a Google Books search doesn't show the keyword I'm looking for in that book.

Re: Why wood pulp is world's new wonder material

#3

This brief article about current uses of wood pulp reminded me of something I read in a book back in the 1970s about a proposal to build an aircraft carrier during World War II (when there was a shortage of steel) out of a mixture of wood pulp and water ice. That material was called "pykrete," after the name of its inventor, Geoffrey Pyke. The shortage of steel was alleviated, and plenty of aircraft carriers construc…

That's really fascinating. The boat sounds almost like a mobile version of the huge wall of ice in Game of Thrones. I could see this used to construct space stations and vehicles, to be used where the vacuum of space prevented thawing.

Re: Why wood pulp is world's new wonder material

#4

This brief article about current uses of wood pulp reminded me of something I read in a book back in the 1970s about a proposal to build an aircraft carrier during World War II (when there was a shortage of steel) out of a mixture of wood pulp and water ice. That material was called "pykrete," after the name of its inventor, Geoffrey Pyke. The shortage of steel was alleviated, and plenty of aircraft carriers construc…

That's really fascinating. The boat sounds almost like a mobile version of the huge wall of ice in Game of Thrones. I could see this used to construct space stations and vehicles, to be used where the vacuum of space prevented thawing.

Vacuum doesn't prevent thawing. Vacuum is an insulator against mechanical heat transfer, but it doesn't do anything against radiative heat transfer. Better not bring that pykrete hull anywhere closer to the Sun than, say, Mars.

Also, cellulose is harder to find in space than carbon, iron or aluminum, currently.

Re: Why wood pulp is world's new wonder material

#5

This brief article about current uses of wood pulp reminded me of something I read in a book back in the 1970s about a proposal to build an aircraft carrier during World War II (when there was a shortage of steel) out of a mixture of wood pulp and water ice. That material was called "pykrete," after the name of its inventor, Geoffrey Pyke. The shortage of steel was alleviated, and plenty of aircraft carriers construc…

That's really fascinating. The boat sounds almost like a mobile version of the huge wall of ice in Game of Thrones. I could see this used to construct space stations and vehicles, to be used where the vacuum of space prevented thawing.

If I recall my science correctly water ice would sublimate in the vacuum of space: http://askville.amazon.com/water-evaporate-vacuum/AnswerView...

Re: Why wood pulp is world's new wonder material

#6

This brief article about current uses of wood pulp reminded me of something I read in a book back in the 1970s about a proposal to build an aircraft carrier during World War II (when there was a shortage of steel) out of a mixture of wood pulp and water ice. That material was called "pykrete," after the name of its inventor, Geoffrey Pyke. The shortage of steel was alleviated, and plenty of aircraft carriers construc…

I remember reading this many years ago. I don't think it is mentioned in the wikipedia article but a further benefit of pykrete was that it would make an aircraft carrier almost immune to torpedo attacks. I didn't see any backup to this but I seem to remember that the aircraft carrier would have a hull of pykrete 14 foot thick, which judging by the bullet tests mention in the article, might have made it exceptionally strong.

I am going on memory on this so happy for someone to correct me.

Re: Why wood pulp is world's new wonder material

#7

This brief article about current uses of wood pulp reminded me of something I read in a book back in the 1970s about a proposal to build an aircraft carrier during World War II (when there was a shortage of steel) out of a mixture of wood pulp and water ice. That material was called "pykrete," after the name of its inventor, Geoffrey Pyke. The shortage of steel was alleviated, and plenty of aircraft carriers construc…

http://en.wikipedia.org/wiki/MythBusters_%282009_season%29#P...

Re: Why wood pulp is world's new wonder material

#8

This brief article about current uses of wood pulp reminded me of something I read in a book back in the 1970s about a proposal to build an aircraft carrier during World War II (when there was a shortage of steel) out of a mixture of wood pulp and water ice. That material was called "pykrete," after the name of its inventor, Geoffrey Pyke. The shortage of steel was alleviated, and plenty of aircraft carriers construc…

I can't find footage, but Mythbusters had a pretty impressive episode where they tested various formulations of pykrete. Jamie's newspaper-based one seemed to be the strongest. A smallish piece of it held a pile of lead, plus Adam's entire weight, while he smacked it with a hammer repeatedly. They built a little boat out of it which disintegrated pretty quickly. The idea that you could build an aircraft carrier was deemed "plausible but ludicrous". http://mythbustersresults.com/alaska-special-2

Re: Why wood pulp is world's new wonder material

#9
post #6

This brief article about current uses of wood pulp reminded me of something I read in a book back in the 1970s about a proposal to build an aircraft carrier during World War II (when there was a shortage of steel) out of a mixture of wood pulp and water ice. That material was called "pykrete," after the name of its inventor, Geoffrey Pyke. The shortage of steel was alleviated, and plenty of aircraft carriers construc…

I remember reading this many years ago. I don't think it is mentioned in the wikipedia article but a further benefit of pykrete was that it would make an aircraft carrier almost immune to torpedo attacks. I didn't see any backup to this but I seem to remember that the aircraft carrier would have a hull of pykrete 14 foot thick, which judging by the bullet tests mention in the article, might have made it exceptionally…

This sounds unlikely. From what I understand, torpedoes do most of their damage by causing hull flexion of the target ship by exploding underneath rather than punching a hole in the hull itself. An incredibly heavy, inflexible hull seems like it would be easier to crack as opposed to some material that has the ability to bend and absorb shock.

I'm not an expert either so hopefully one of our naval folks will come in and clear it up.

Re: Why wood pulp is world's new wonder material

#10
>it is made from a tightly packed array of needle-like crystals which have a strength-to-weight ratio that is eight times better than stainless steel.

That's a pretty useless thing to say. What kind of strength? Tensile? Shear? Yield?

Maybe this figure is buried somewhere in the paper they linked to, but not in any easy to find place.

Post reply on HN