Indestructible silk: good armor?

Question

I've been playing with different conceptualizations and types of armor for historical settings, especially armor with magic enchantments or made from weird materials. I was stuck thinking about lightweight protection and remembered that mithril shirt from the Lord of the Rings: The Fellowship of the Rings.

To those who haven't seen or read it, the mithril shirt is described as being stronger than steel but as supple as linen. This latter property confused me when the wearer got stabbed with the force of a battering ram, since the shirt would be fine, but the person wearing it should be suffering massive blunt force trauma and internal bleeding. Heck, with that degree of flexibility, you could even justify the shirt being forced inside the person wearing it.

With that in mind, would a silk shirt or coat that is (for all intents and purposes) indestructible, be useful as martial protection, or would it just be over-designed pajamas? For the purposes of this thought experiment, imagine the wearer of this shirt being struck by an arrow, a knife, a spear, and an ax.

Answer 1

Silk armor was used for this purpose by several real historical armies. It's not going to STOP the blow the way I think you're imagining, but it does a few very useful things. It cushions the blow quite a bit, and against piercing weapons the silk will bind up around the point. So, to your point, it DOES get forced into the person wearing it, but that's actually one of the key benefits.

In the case of arrows it makes them much easier to remove without causing further damage, AND by keeping a layer of material that has its own antibacterial properties between your innards and whatever you got stabbed with, it dramatically reduces the chances of infection.

So, if you want armor that will completely protect the wearer from getting slashed or stabbed, silk isn't going to do that. You need something very rigid and strong like plate armor for that.

BUT, if you want very lightweight, comfortable armor that doesn't slow you down, and makes it much more likely that you're going to SURVIVE being slashed or stabbed, silk will do that all day long and twice on Thors-day.

EDIT: I feel like I need to address a misconception I'm seeing in a number of responses, and emphasize the counterargument others have raised. If your indestructible silk has the same flexibility as real silk does, and you're wearing it loose, it will not prevent sharp force trauma. I have personal experience with this. It was denim in my case, not silk, but a sharp steel edge opened up a gash four inches across in my leg all the way down to the bone without actually cutting through the denim. You'd need to have padding underneath to prevent the silk from just forming an edge around the blade. Otherwise you still get wounded, it's just a very clean wound.

EDIT the Second: I didn't REALLY address indestructible silk versus the normal kind very well, so I'll elaborate a bit. Assuming that indestructible silk (like mithril) is rare and expensive, and if you have some you want to use it as effectively as possible, there are a couple ways you'd do it.

If you're a wealthy urban noble and you're worried about assassins and duels, then you can use it all by itself under more normal clothing, with all the pros and cons I noted above. You would ESPECIALLY want to make sure you've got matching GLOVES, because being able to protect your hands and arms from getting sliced during a rapier duel or knife fight is a HUGE advantage. The general wisdom in knife fighting is just accept that your arms and hands are going to get cut all to hell, and to keep your opponent from hitting anything vital until you can beat him, and hope you don't die of blood loss first. Rapiers are sharp, but don't have a lot of mass behind them so against a weapon like that, the silk will often cause what would be a deep stab into a glancing poke.

Now, if we're thinking about battlefield armor where you're expecting to get hit, and hit HARD, all day long, then you'd want the silk to be part of a gambeson or suchlike, with the silk layered over nice thick padding everywhere except the joints. If it were me, I might want a tough layer of leather over the top of that in certain places for things like fire, because silk doesn't really prevent heat transfer all that well.

All that would only slow you down about as much as a really heavy wool coat would (I used to have a Surplus Swedish Army Greatcoat I was very fond of), but would allow you to at least survive just about any human-scale armed strike I can think of, and would shrug off entirely anything that wasn't a direct hit.

Answer 2

Its going to be extremely practical, with advantages and downsides compared to solid armors. Although it depends on how flexible exactly it is how good/bad it might be, less flexibility can help divide the forces across a larger bodily surface area. There are solutions for this.

Against arrows its going to be useful, it wont be pleasant getting hit but it'll not be lethal until you get hit by dozens to hundreds as you are slowly pummeled to death. Gives you time to get out of the way or have a few words with whoever is doing it, preferably with a sharp object.

Against knives it's useful. The opponent wont be able to cut you directly and it'll basically be a punch. However, if the material is too flexible the edge of the knife will still concentrate this punch force and make for a more dangerous punch. Ultra flexible and the material might just envelop the knife's edge and be almost as sharp as the knife, cutting you anyway indirectly!. Dont make it too flexible!

A spear is similar to a knife but on a stick and easier to put more force behind the jab.

An axe is similar to knife as well, but with more weight and a different trajectory behind it.

If you have access to this the weight and freedom of movement are its key advantages, and being able to wear this on a long march and still have energy to fight is going to be useful. Any flexibility issues can be solved by using leather armors beneath to spread (and cushion) the forces of a blow to your armor. Potentially even something like a thick layer of something light and cushioning, like wool, could work as well.

Edit because of popular comment: this fabrics most important purpose would be as a top layer over padded material. Getting stabbed or similar while only wearing a thin silken indestructible vest is still going to be worse than a normal punch. Similar to plate armors this wont do much against maces, flails and other blunt force objects where only more and more padding will provide protection.

Answer 3

When we talk about bulletproof vests, we have to keep in mind that, compared to being pierced by a projectile, anything which gives less damage is to be preferred.

Bulletproof vests work by:

• spreading the impact on a larger surface, thus giving, for the same force, a lower pressure
• spreading the momentum over a longer time, which following the relationship $m \times \delta v = F \times \delta t$, results again in a lower force

But still the inflicted damage is non zero. Blunt traumas can be a consequence, broken ribs too.

So, to answer your question, yes, it would be useful to lower the damage consequent to an attack, but it won't completely avoid any damage.

Answer 4

This actually might work in a very limited way, but it needs rigidity added.

You could have this silk armor as a base layer, then add a chest plate, shoulder pads, helmet, and braces and have competent armor as all your vitals are now protected. All your laceration prone spots are protected by the silk. Add leggings if horse combat is required.

The rest of your body is largely bone and muscle, and can take a blunt force hit fairly easily comparatively speaking. The trade off for speed and flexibility might be worth the extra vulnerability.

Answer 5

It could work but not by itself.

It needs to be over some kind of ridged structure to keep it stretched tight.

The reason it won't work by itself is that it will deform and allow kinetic energy to be transferred to the body behind it.

Yes, you won't get cut but that doesn't help you if the blow from the axe shoves the silk shirt through your sternum and heart. The only good thing is that you can pull it out of the body, wash it off and then give it to someone else.

Also, silk is flammable. Does being indestructible stop that or does it leave the wearer in a burning shirt that they can't get off?

Answer 6

If your 'indestructible' silk armour is as thin and flexible as pyjamas then its biggest flaw is as you've already noted: it does little to protect against blunt force trauma. It's still really useful and practical for keeping out the point ends of axes and arrows but it does nothing to stop the wearer from being clubbed to death.

This silk armour would be much more effective when worn over a gambeson or thick furs. They'd provide exactly what your super silk lacks, padding to cushion against blunt force. When paired I think the combination would prove superior to plate mail, as it'd provide as much protection(actually more since plate does little against a mace or warhammer) while being much lighter, inhibiting mobility a lot less and also insulating against cold.

TL;DR: Frodo should've worn a gambeson as well

Answer 7

The reduction to blunt force damage will be related to the softness and thickness of the material. In the case of thin silk armor, probably not very much. This could be increased by wearing the armor loosely, making for a sort of air-barrier.

However, if the armor was tightly fitted to the person's skin, then the force required to pierce someone by forcing the silk into them will be the same as the force required to compress their entire body; it would be a significant help against arrows and knives.

Answer 8

Silk was generally worn the the undergarment for reasons noted above. It's worth noting though that Kevlar an carbon filament armour is usually part of a composite involving resin to provide stiffness.

Answer 9

If it is truly indestructible, then YES!

If your silk is really indestructible, then a little bit of molten-metal forging will not bother it at all.

So make fiberglass armor out of it. Except, don't use glass fibers, use the silk. And don't use silly resin, use the hardest steel you can lay your hands on. !!not the toughest, you want hard!!
If you have the means to forge diamond, that would be ideal.
The addition of utterly unbreakable strands in the hard material will render it as resistant to damage as mere physical material can get. To penetrate this composite armor, you would need to break each and every bond between the steel and the fibers, just to enable a local breakthrough. But your steel is saturated with millions of unbreakable strands.

In effect, to penetrate a hard steel bound to unbreakable silk substrate, you would need to powder the steel finer than the gaps between the silk strands!!

Impact aside, I can see a 1mm layer of this armor stopping a railgun projectile. The anti-Yamato-Battleship type railgun.

Funny things happen to material sciences and physics when one starts throwing around terms such as "infinite" and "completely indestructible"

footnotes: For the silk to be truly indestructible, it must not stretch. At all.
It must not break, ever.
This means its Young's Modulus needs to be.. infinite.
This also mean that the speed of sound in the strands is.. infinite.
This means that any mechanical stress applied to an object comprised of these strands, is simultaneously and equally applied to every strand, ever position in the object, equally.
It does not matter if the impacting object is a pin of a bowling ball, the impact is distributed to the whole object, equally.

I have absolutely no clue how one would go about even bending a strand of the stuff, much less penetrating armor made out of it. You could cut a black hole in half with this stuff!

I think we should quantify "indestructible" with some numeric, non-infinite number. For the safety of all existence.

Answer 10

It would be perfect for armor, look at the medieval gambeson.

Granted the Gambeson was a reasonably bulky piece of clothing and wearing it was the equivalent of walking around in a heavy winter coat all day, so it might not be entirely what you are looking for in terms of armor, but it is the lightest effective armor known during medieval style period. It was the primary armor used across most cultures of the time as it was cheap and easy to create and repair.

https://en.wikipedia.org/wiki/Gambeson

It is made of many layers of quilted wool or linen cloth, approximately 18 to 30 layers and was great protection from most common threats a soldier would face on the battlefield.

The thickness of the fabric allowed it to act as padding against many blunt force trauma weapons, while not foolproof it did lessen the impact by a good deal, which is why it was often worn under maille, plate, and brigandine armors to pad against blunt force.

Against slashing blows the gambeson would have the upper layers cut, but unless a mighty blow was struck by a very impractically sharp sword it would not cut all the way through.

Against piercing weaponry such as arrows it isn't perfect defense as they would still penetrate through by pulling the weave apart, but if thick enough, could stop the occaisional arrow or dagger thrust.

Now if your Gambeson was made of indestructible silk the whole ballgame is changed, because now it would be impervious to slashing cuts, there is no way a blade would be able to slice through no matter how sharp.

However that being said, against blunt trauma due to it's layered cushioned structure, it was a good cushion allowing for the wearer to shrug off most things short of a pretty hefty mace. If the fabric had enough layers, I'd wager it could turn a most likely fatal hit from a rifle into a big bruise.

Against piercing weaponry it would improve quite substantially, because anything short of a thin point designed to pierce this armor would be shrugged off like a slashing weapon, However this would lead to the development of needle-like arrows and blades that can poke between the fibers of the fabric, so it wouldn't be foolproof but way better than anything else available short of full plate armor.

So, in short, your silk armor could work very well, but only if properly layered.