Saab Barracuda Soft Armour

But why isn’t this just very expensive sand?
I imagine some of the protection comes from the willingness of the balls so shuggle around, and ceramic is probably harder than silicon, but really?

I guess they’ve been to Lakeland: Ceramic baking beans

Video 1 shows a problem – that of the beans becoming more tightly ordered with vibration. A gap in the protection started appearing at the top of the panel.

The Victorians did even urban sprawl (not just infrastructure) better than us. South of the Thames the Blitz bomb damage on buildings hit by bombs falling very close to them defied the received wisdom on what structural damage should have been.
– so many houses had been built on these sorts of ball bearings, even if the rivers that produced them have long since dried up (some went underground, too)

So Barracuda is a whole brand (by Saab) now, their infrared nets (not just camouflaging the heat generated inside,but also deflecting what is coming in in hot conditions) have been around for decades

@ADGareth

I think the collapse is due to consumption of the ceramic beads. They are being broken into powder in absorbing the energy, but the remainder remain inflexibly packed in body-centred-cubic and drop down.

@ACC
Didnt know that. Cool.

The ancient Pagoda has a neat trick too. Wonder if there is a role for that in a blast-resistent structure.

http://www.economist.com/node/456070
http://www.sciencechannel.com/tv-shows/what-the-ancients-knew/videos/what-the-ancients-knew-ii-shorts-pagoda-construction/

Without changing to a different continent, the Swedish army tested igloos as artillery shelters

An igloo taking a 105mm hit would shatter’ but the air in the ice would dissipate the blast. So, if you had a truck (a tank would do, too) inside, it would be ready to roll (saves building a door).

Of course, building igloos that big required a lake next to you. A workable, but not a practical idea.

I remember building a “shovel up” as a child, as there was just a couple of inches of snow around, and ice blocks were definitely unavailable.

You get a spade and scrape and pile wet snow into a big mound.
Then you excavate a tunnel into the mound, and shovel the debris out on top, where it “sets”. Then repeat and repeat, as far as you dare, until the original solid mound is expanded into a rather shabby, lumpy dome (“igloo”).

Sitting inside (which was amazing, given it had been a pile of snow an hour before) you can see through the roof. Even more so, you can walk and jump on top of it without it breaking or you falling through.
Magic. And good protection too.

Can you build these by hot air blowing (wet) snow over a pneumatic mould?
Its the heat-and-refreeze which makes it solid, and which you would have to address in (dry) arctic snow.

Just a thought. May be strong enough and you don’t need a lake.

Would not pea gravel be cheaper?

Pete:
Why limestone?

Found mention of Terrell’s invention in this article from Wikipedia.
Fantastic story, with parallels to Harrison’s watches (see Longitude by Dava Sobel).

Can someone make a film of it please?
http://en.wikipedia.org/wiki/Plastic_armour

PS still don’t see why limestone’s included, unless its just lighter/cheaper than all granite.

I have just read the article on the plastic armour ,very good cheap solution to a deadly problem, German aircraft and e- boats machine gunning merchant ships deckhouses. The inventor,Mr Terrell , was originally a Barrister before the war and had dealings then with the Penlee Quarry company in which he later acquired shares. He insisted to the Admiralty that the Penlee granite be used . “Terrell, who owned shares in the company, would go on to insist that Penlee granite be used for plastic armour, whatever its material qualities”

I think I read that at the end of WW2, the Japanese were short of materials, so they armoured the deck of a carrier with a mixture of concrete mixed with sawdust & rubber, to give it flexibility.