Spec me a dragon proof castle, bitches!

[Joose]

A question occurred to me, due to a combination of a comment made on The Crate & Crowbar and reading a book about Game of Thrones. Castles in fantasy fiction tend to be basically the same as real medieval castles, but the threats they are defending against are not the same. Of course, most of the threats are not the same but can be defeated by similar means: A big wall and a pot of boiling oil is going to work just as well against an Orc as it is a human. Against dragons, on the other hand, traditional defenses are a bit shit.

This is highlighted by Harrenhal in Game of Thrones (dont worry, no spoilers here. This all happened before the time the books are set). For those of you that don't know, Harrenhal was the biggest, most impressive castle ever made. Hugely thick and high walls, a deep moat, huge stores of food and an internal supply of fresh water made it as close to impregnable against traditional attack/seige as it could be. The guy who brought it down had a dragon though, so he just flew over the wall and sat in the courtyard spewing fire until everything inside was cooked.

I guess the explanation for why GoT castles were built like this even at a time when dragons were around would be that the only defence against dragons is hoping your opponent doesn't have any. Thats not very satisfying though.

So, how would you build a castle to make it defend better against dragons? It doesn't have to be 100% effective (no defence is) just better than nothing.

Assumptions:

1) Apart from the dragon, all physics are as reality. No magic shields or anti-dragon amulets.
2) The technology available to you is approximately medieval. Trebuchets yes, cannon no.
3) You are a rich king or similar, so resources are not an issue. Have as much as you want.
4) The dragon is a traditional, middle of the road dragon. About the size of a bus, flies, breathes fire. Scaled, but not completely impregnable (lets say roughly equal to a hippo in terms of defence), appropriately strong for a creature that size (very, but not unlimited) and for simplicity lets say the breath is roughly the equivalent in power to a WW2 flamethrower. It has infinite fuel but has to breathe out to flame, so cant just flame non stop. Assume that it is either about human intelligence or it has a human rider, up to you which.

[Dr. kitteny berk]

one cave please!

[fabyak]

That was my thinking too, something carved into the side of a mountain so there is only a small amount that would be vulnerable to aeriel attack

[Joose]

I thought cave at first, but you are defending yourself against dragons at the expense of making your castle less good in all other respects. There is a reason why real cave castles are super rare.

Main problem being where you build your castle is almost as important as how you build your castle. You need to build it somewhere tactically/strategically important (or why bother building it at all?), but defendable, with access to fresh water and good visibility of the surrounding area. There is a reason castles tend to be built on top of hills or on lakes. Caves tend to not be on top of hills or on lakes. You would be nicely defended against aerial attacks, but wouldn't know a conventional army was coming to kick your teeth in until they were right outside.

Carving it into the side of a mountain might be a decent idea, but again it limits you to only be able to build your castle where there are mountains. What if the country you are defending has landscape like... well, most of England. Decent sized caves are not exactly abundant and most of England it no where near a mountain.

In fact, the more I think about it, the more a cave castle seems like a bad plan. You have only one side to defend (where the cave opening would have been), which is good, but you can only defend it by walling the thing up entirely and putting arrow slits in it. So I sidle up along the side of the mountain (or come down from the top) on my dragon and squirt fire through the arrow slots. Whilst you are running about trying to put out your archers, I walk my conventional battering ram up to your front door unhindered and bash it down at my leasure.

Alternatively, I sidle doods up along the side of the mountain and set a bunch of shit on fire in front of your castle. Enjoy your not breathing anymore!

Only having one side to defend is heavily balanced by having not being able to defend your other sides even if you want to.

[Dr. kitteny berk]

Ideally, I think you wanna build a massive fucking castle, all disney style and shit.

Let the plebs live there, have a nice house a mile or 2 out and watch the bbq.

[Mr. Johnson]

Build whatever castle you like and hire Beowulf as your resident dragon-slayer.

[Dog Pants]

Lots of ballistas would seem to be the best approach to bringing the fucker down, and possibly mortars firing cannister. Pretty sure they could do that in medieval times. The problem is keeping your dudes alive long enough to fire it. Flamethrowers were designed to be bunker-busters, and they were really only proven to be tactically unviable because they were short ranged, had limited ammo, and were fucking heavy. None of those apply when the apparatus is a flying Churchill Crocodile. That was so effective that, to quote that wiki page, "it was used so successfully against bunkers that many bunkers surrendered after the first ranging shots." So one on one I reckon a ballista on top of a turret is fucked. You could put it under a cover if you like, and I think that would then require the wyrm to make a direct hit on an aperture, but by the same reckoning you're reducing your field of fire. However, add more towers and you then have a chance to shoot it while it's on its attack run. Those are pretty much going to be fairly predictable lines. So, I'd put as many turrets as I could on the castle. Small ones with at least two ballistas in and metal canopies. None would be impervious by any means, but they would horse it to attack from a lower angle, which would leave it vulnerable to overlapping fire arcs from the other towers. I daresay a few dragon sieges would prompt some pretty speedy development of reloading mechanisms to limit the downtime on each gun. So there we go, medieval anti-aircraft batteries.

[HereComesPete]

If you've got dragons I've got wizards!

I think however that if the only 'magic' is the dragon, then ballista/arbalests with nets, ropes, cannister shot etc to put down the target, then shoot the living fuck out of it.

In terms of castle - you need the view that the mountain top brings, something like krak de chevaliers or the sanctuary atop monte cassino, plenty of visibility and overlapping fields of fire.

[Joose]

Yeah, I think ballistas set up as medieval AA probably is the way to go. Maybe set them up to fire a bunch of large arrows rather than one massive one for a shotgun effect. Ooh, or something like the chain shot used in cannon to take down ships sails: Without gunpowder it wouldn't be as powerful, but it would tangle up a wing enough to fuck up flying and wouldn't be as hard to fire as a net.

[FatherJack]

Sticking with what "actually" happened to Harrenhal, the Dragon's breath is stupidly overpowered - notwithstanding that the dragons were the only airborne attack horse of the age and the Harren's weren't particularly expecting them, I'd say they were rather unlucky rather than ill-prepared.

The dragon's breath completely melted Harrenhall's stone into basically lava. That's rather a bit hotter than your average flamethrower, and a bit hotter than Wildfire - the only analogous substance the puny humans have managed to come up with - like Napalm laced with phosphorus - but with the potential to just-about melt stone which is more than it's real-world analogues can do.

(GRR Martin isn't great on temperatures or melting points, thinking a cooking fire is hot enough to melt gold)

While there's no real defence against that sort of nuclear-level attack, the instigating dragon does have to be quite close to effect it. It's unclear whether wildfire would actually harm a dragon, but it is hinted at that large pointy objects fired at a dragon's tummy aren't conducive to its continued existence - so basically my defence would consist of lots of ballistae with sharpened tree-trunks pointed upwards in key areas. They could be tipped with iron, steel or obsidian depending whichever lore told of greater success.

[Joose]

Well, its not like he landed, went "huff!" and the walls instantly turned to candles. He sat in there for a while belching into all the castles nooks and crannies, gradually increasing the heat of the place over time. Even then, although a lot of the castle went a bit melty there is still enough of it left to be a fortification worth coveting.

But yeah, I think the best defence against a dragon probably is twatting the thing before it gets close enough to flame you.

[buzzmong]

Balloons!
Tie enough to the castle and float high enough, there won't be enough oxygen for a Dragon to beltch flame. Granted, your loyal subjects may have also asphyxiated, but there's always more peasants.