Got a Real-World Weapon, Armour or Tactics Question? Mk. XXIX

[Pauly]

A question about building fortifications:

Assume you want to raise a US Civil War-style earthwork (with stone topping) wall around a relatively small area. But you need to do it before winter sets in--you have roughly 3 months. How much manpower would you need? Are there better (ie cheaper and/or faster) ways of doing this?
(palisade style).

If it’s civil war era which implies gunpowder cannons, you do not want stone, least of all small stones that haven’t been expertly masoned into position.

Stone shatters and creates shrapnel. Packed earth is all around better. Packed earth gambions were heavily used in the ACW as were sandbags. Stone, if used, would be better on the interior facing of the walls and allowing the packed earth to absorb the shock of cannon balls. You may have some interior stone buildings, but that would be to protect against stray ricochets and musket balls not aimed direct cannon fire.

Depending on the expertise of the engineers your basic design will be along the lines of a Vauban star fart with bastions and ramped walks deflecting cannon shots upwards. Ditches in the front to slow down assaults.

If you’ve got druids available you could grow grass on the sod to help keep it in place and bomba bushes as natural barbed wire where required, possibly in the ditches.

As previously sad 3 months is more than enough time to build an elaborated earthworks.

[fusilier]

What I was thinking was that the wall would look like (seen from the outside):

1) ditch
2) small horizontal space to keep the dirt from tumbling in
3) packed earth (probably sodded with the heavy sod from the ditch to prevent rain from washing it away) slope, roughly triangular but with a flattened top several feet wide, about 8-10' high at the peak.
4) held in place with a field-stone + mortar retaining wall that also serves as the patrolling walkway.
5) (eventually) with a shorter regular stone wall, 5-6' tall, on top of the earth slope as as breastwork.

The point being to not need quite so much stone/stonework because all you're using it for is to support one side of the wall, not facing it.

I did some calculations and it seems doable just in earth-moving time assuming you have the equivalent of a mini-excavator + roller (in the ritual crew) and then most of the labor being building the retaining wall. Estimate was you have about 50 cubic feet of earth in a 1-foot-wide segment, or (roughly, with rounding) 6 m^3 per m of wall. From that and excavator speeds, I figured you could probably handle somewhere between 40 and 50 m of wall per day (just in earth-moving time), so I said roughly 1 month (32 days, in setting, as a round number) for a 200'x200' area (basically 1 acre) assuming you had one specialist crew and "plenty" of less-skilled labor. Shorter if you can hire another specialist crew (the real limiting factor here).

Seeing as the ditch is made out of the same dirt as the wall, the angle should be the same, and you won't need a small berm between the ditch and wall. While sometimes used on larger fortifications, it could be undesirable as it might make it easier for enemies to climb.

So what kind of cross section are you imagining? A typical civil war earthen fort, with walls as high as you describe, would have a very wide "firing step." The parapet would be roughly breast high when standing on this "step." The interior of the parapet would be "revetted", some material would be used to make it vertical, and prevent earth from spilling *into* the work. This allows the soldiers to stand next to the wall to fire their muskets over the top. Typically all interior edges would be revetted, but it wasn't always done.

However, it appears that you intend just an earth wall, 8-10 feet high, that soldiers can stand on top of? That fits with some older (pre-musket) styles. Given that you're using prairie sod, I don't think you even need to pave the walkways with stone. The sod should be tough enough to take being trodden upon. Maybe use some stone to provide steps to the top? Or terrace the interior so that it's easier to get to the top? Gaps in the earth wall, for things like gates, entryways, posterns, etc., can be faced with stone.

[PhoenixPhyre]

Seeing as the ditch is made out of the same dirt as the wall, the angle should be the same, and you won't need a small berm between the ditch and wall. While sometimes used on larger fortifications, it could be undesirable as it might make it easier for enemies to climb.

So what kind of cross section are you imagining? A typical civil war earthen fort, with walls as high as you describe, would have a very wide "firing step." The parapet would be roughly breast high when standing on this "step." The interior of the parapet would be "revetted", some material would be used to make it vertical, and prevent earth from spilling *into* the work. This allows the soldiers to stand next to the wall to fire their muskets over the top. Typically all interior edges would be revetted, but it wasn't always done.

However, it appears that you intend just an earth wall, 8-10 feet high, that soldiers can stand on top of? That fits with some older (pre-musket) styles. Given that you're using prairie sod, I don't think you even need to pave the walkways with stone. The sod should be tough enough to take being trodden upon. Maybe use some stone to provide steps to the top? Or terrace the interior so that it's easier to get to the top? Gaps in the earth wall, for things like gates, entryways, posterns, etc., can be faced with stone.

So what you're proposing has the wall be simply the extension of the ditch's inner surface? That could work. As for cross-section, I had been working under the (mistaken, it seems) assumption that dirt-moving was the bottleneck here and thinking of it as a right triangle, roughly as wide as it is tall, so probably 11 ft across at the base, ramping up at a (roughly) 45 degree angle for 8 feet, then a 3 foot "walk" on the top, with the vertical side being held up by a field-stone retaining wall. That was to save on dirt needing to be moved. But if, as it appears, dirt-moving isn't the binding constraint, I could instead just do a roughly 20' wide (at the base) flat-topped triangle--8' of slope, then 3-5' of flat, then 8' sloping down on the inside. Then put a field-stone wall, roughly 4-5' high (with battlements) on top for cover for soldiers on the top.

Note--this is more in the vein of a "keep out incidental raids and mark the border" wall, not a "stop a horde of orcs" wall. And as a setting fact, there are no guns. Period. The creator god (aka ME) strongly dislikes them on aesthetic grounds and has designed the entire physics and chemistry to make it impossible. Magic-shooting artillery? Maybe (although that's not easy or common). Gunpowder (or any explosive-powder equivalent) cannons and muskets? Nope. Not gonna happen.

One other side note--the culture in question shouldn't have much problem with the skills for building walls--their (common-language) culture name is the Wallbuilders. They build walls of some sort (ranging from a token string-and-stake border marker to one city having multiple stacked, serious stone walls cutting off access to the city, which nestles in a pocket canyon with inaccessible cliffs on all but a small approach. They're somewhat of defensive specialists. However, no one in the region has fought a serious war[1] in, well, centuries. First because there was no one neighboring to war against (expanding into wilderness), then because there's an international organization who owns all the adventurers/superheroes who tends to stomp on serious wars hard.

[1] there have been skirmishes and a protracted "civil war" that was basically just a bunch of feuding groups raiding each other, but those raids had force sizes in the low hundreds at most. Most of the nations of the region have only token militaries. Lots of monsters on the borders, but this area is way far away from any of the wilderness.

[fusilier]

So what you're proposing has the wall be simply the extension of the ditch's inner surface? That could work. As for cross-section, I had been working under the (mistaken, it seems) assumption that dirt-moving was the bottleneck here and thinking of it as a right triangle, roughly as wide as it is tall, so probably 11 ft across at the base, ramping up at a (roughly) 45 degree angle for 8 feet, then a 3 foot "walk" on the top, with the vertical side being held up by a field-stone retaining wall. That was to save on dirt needing to be moved. But if, as it appears, dirt-moving isn't the binding constraint, I could instead just do a roughly 20' wide (at the base) flat-topped triangle--8' of slope, then 3-5' of flat, then 8' sloping down on the inside. Then put a field-stone wall, roughly 4-5' high (with battlements) on top for cover for soldiers on the top.

Note--this is more in the vein of a "keep out incidental raids and mark the border" wall, not a "stop a horde of orcs" wall. And as a setting fact, there are no guns. Period. The creator god (aka ME) strongly dislikes them on aesthetic grounds and has designed the entire physics and chemistry to make it impossible. Magic-shooting artillery? Maybe (although that's not easy or common). Gunpowder (or any explosive-powder equivalent) cannons and muskets? Nope. Not gonna happen.

One other side note--the culture in question shouldn't have much problem with the skills for building walls--their (common-language) culture name is the Wallbuilders. They build walls of some sort (ranging from a token string-and-stake border marker to one city having multiple stacked, serious stone walls cutting off access to the city, which nestles in a pocket canyon with inaccessible cliffs on all but a small approach. They're somewhat of defensive specialists. However, no one in the region has fought a serious war[1] in, well, centuries. First because there was no one neighboring to war against (expanding into wilderness), then because there's an international organization who owns all the adventurers/superheroes who tends to stomp on serious wars hard.

[1] there have been skirmishes and a protracted "civil war" that was basically just a bunch of feuding groups raiding each other, but those raids had force sizes in the low hundreds at most. Most of the nations of the region have only token militaries. Lots of monsters on the borders, but this area is way far away from any of the wilderness.

This sounds reasonable to me. I did remember I have a "Hand-Book of Active Service" which does have some information about field fortifications. I don't see anything about digging rates, but it does recommend a 45 degree slope for the earth, as your calculations used.

I would still consider using "fraise" (large pointed sticks sticking out from the base of the earthwork), if the wood can be found. At the very least it looks cool. ;-) It's also got a long history in the use of field fortifications.

[PhoenixPhyre]

This sounds reasonable to me. I did remember I have a "Hand-Book of Active Service" which does have some information about field fortifications. I don't see anything about digging rates, but it does recommend a 45 degree slope for the earth, as your calculations used.

I would still consider using "fraise" (large pointed sticks sticking out from the base of the earthwork), if the wood can be found. At the very least it looks cool. ;-) It's also got a long history in the use of field fortifications.

Good to know that my "make the math easier" simplification, which I arrived at by looking at a table of angles of repose, was about right.

I think that instead of fraise (because wood long enough to be meaningful is really scarce here[1]), I'll instead use thorn bushes, which are...not scarce. And grow big and gnarly and tangled. Plant those in the ditch and you'll strongly discourage people passing through.

[1] In fact, wood isn't used for fuel at all except as a show of ostentatious wealth. Instead, there's a (fantasy) form of bush, something like a compact tumbleweed that burns for a long time. That, plus animal dung, provides much of the heat and cooking fuel. Culturally, they're all about planting trees (often as wind-breaks or orchards)--cutting down live trees is discouraged. Much of the native wood that ends up used for things came from dead or dying trees. The rest was floated down the major rivers from the heavily-wooded hills and mountains ~100 miles away.

[Pauly]

Note--this is more in the vein of a "keep out incidental raids and mark the border" wall, not a "stop a horde of orcs" wall. And as a setting fact, there are no guns. Period. The creator god (aka ME) strongly dislikes them on aesthetic grounds and has designed the entire physics and chemistry to make it impossible. Magic-shooting artillery? Maybe (although that's not easy or common). Gunpowder (or any explosive-powder equivalent) cannons and muskets? Nope. Not gonna happen.
.

For fortifications.
- Tall vertical obstacles keep out people (and orcs et al). Thickness is only a consideration in answering the question “how hard is it to make the wall less tall?“
- Sloped thick obstacles keep out firepower. A trench is essentially a fortification with infinite thickness walls. Height only matters in making fields of fire for your defensive batteries.

The purpose of sloped fortifications in ancient forts was to make it harder to get over the vertical part of the wall. As soon as fortification technology was sufficiently advanced defenders built vertical walls of sufficient height and abandoned sloping earthworks as part of the built defenses. Even then forts were built on the top of hills where possible.

In the absence of cannons, or the magical equivalent, there is no need to make thick sloping earthworks a part of your fortification, unless it exists to put a tall wall on the top of it.

[PhoenixPhyre]

For fortifications.
- Tall vertical obstacles keep out people (and orcs et al). Thickness is only a consideration in answering the question “how hard is it to make the wall less tall?“
- Sloped thick obstacles keep out firepower. A trench is essentially a fortification with infinite thickness walls. Height only matters in making fields of fire for your defensive batteries.

The purpose of sloped fortifications in ancient forts was to make it harder to get over the vertical part of the wall. As soon as fortification technology was sufficiently advanced defenders built vertical walls of sufficient height and abandoned sloping earthworks as part of the built defenses. Even then forts were built on the top of hills where possible.

In the absence of cannons, or the magical equivalent, there is no need to make thick sloping earthworks a part of your fortification, unless it exists to put a tall wall on the top of it.

But what if making a tall wall costs too much/would take too long? This is, in essence, a temporary wall. Eventually, they'll probably put up a taller, vertical wall. But they'd never be able to source enough stone for a 10' wall, let alone anything taller, before winter, let alone build the darn thing. At least without way more resources than they have.

As I see it, the hybrid approach gets you some of the benefits of the vertical, while being much cheaper/faster. If they were in the mountains or forests, the calculus would change to favor stone and wood. And field stone (which isn't all that common there either, but more than blocks of cut stone) is extremely labor intensive at scale.

Plus, there are aesthetic considerations. This particular culture has a history of using earth as a building material. Cob-style rammed earth buildings are the norm, with only rich buildings being timbered.

[Martin Greywolf]

I think that instead of fraise (because wood long enough to be meaningful is really scarce here[1]), I'll instead use thorn bushes, which are...not scarce. And grow big and gnarly and tangled. Plant those in the ditch and you'll strongly discourage people passing through.

Not really. I remember one occassion where I, a re-enactor with 1300 padded leg armor and leather boots, was a part of a LARP, with most of the LARPers using the usual not-that-durable costumes. A fight broke out, as it does, and I gleefully stomped right through thorn bushes, knowing full well my armor and actual, proper boots can take it, to flank the enemy shield wall. Unless your thorn bushes are some exotic variety with long and durable spikes, anyone with padded armor will be able to get through with a few small nicks in the armor, and anyone in metal will only be slowed down slightly by them.

But what if making a tall wall costs too much/would take too long? This is, in essence, a temporary wall. Eventually, they'll probably put up a taller, vertical wall. But they'd never be able to source enough stone for a 10' wall, let alone anything taller, before winter, let alone build the darn thing. At least without way more resources than they have.

As I see it, the hybrid approach gets you some of the benefits of the vertical, while being much cheaper/faster. If they were in the mountains or forests, the calculus would change to favor stone and wood. And field stone (which isn't all that common there either, but more than blocks of cut stone) is extremely labor intensive at scale.

The main reason this wasn't done is cost and labor. Pallisades and walls go quite a lot deeper down than you probably think, and erecting any earthworks on top of actual surface will make replacing the previous defensive structure a pain - not only do you need to excavate some ground twice, but you need to stabilize the new hole to make sure it doesn't just... fill itself in during the next rain.

This isn't to say walls weren't upgraded, clearly they were, and often, but if you are planning a defensive measures and already know you will be building a stone wall in near future, the logical thing to do is to make a mound-and-pallisade ring that will be fairly far away from where you want your stone wall to be, getting two layers of defense and avoiding having to dig up the same ground twice.

Spoiler: Side slices of several fortification types

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Pallisade and mound

Schematic stone wall

Actual stone wall, note both the scale (that wide base is ~5 meters deep) and the retaining wall to the far right

This was a fairly common practice, although you rarely see it nowadays, most stone castles don't have their pallisades reconstructed, and even then, finding any evidence for or against a pallisade can be a challenge archaeologically.

Spoiler: Beckov castle with reconstructions of two of its pallisade towers visible in bottom right

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The white bits at the bottom is sun-bleached wood that for some reason lost to posterity (of the last two decades) wasn't slathered with whatever product they used to stop weather and bugs from eating it

Plus, there are aesthetic considerations. This particular culture has a history of using earth as a building material. Cob-style rammed earth buildings are the norm, with only rich buildings being timbered.

This was always a weak excuse. Sure, some aesthetic considerations will affect the final look, but when it comes to gross construction, functionality rules over all. There's a reason why fortifications against similar weapons looked almost the same.

Spoiler: Great Wall, Babylon and Spis castle, note the walls

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[Telok]

But what if making a tall wall costs too much/would take too long? This is, in essence, a temporary wall. Eventually, they'll probably put up a taller, vertical wall. But they'd never be able to source enough stone for a 10' wall, let alone anything taller, before winter, let alone build the darn thing. At least without way more resources than they have.

Adobe. Sun, mud, straw. You said they have some experience with bricks? It's a cheap brick wall that should help until a more permanent wall is built.

[Tobtor]

Adobe. Sun, mud, straw. You said they have some experience with bricks? It's a cheap brick wall that should help until a more permanent wall is built.

Depend on climate. Mud bricks will fail unless you a firing them. That requires firewood (it needs quite alot!). Making bricks isn't a short cut to making a wall. It requies about the same time and resources (though it is different resources).

Sure, some aesthetic considerations will affect the final look, but when it comes to gross construction, functionality rules over all. There's a reason why fortifications against similar weapons looked almost the same.

Well... wooden walls and first doesn't last as long, so you cant see them today. That is what we see today is NOT what did did, but only the part that lastet.

Not really. I remember one occassion where I, a re-enactor with 1300 padded leg armor and leather boots, was a part of a LARP, with most of the LARPers using the usual not-that-durable costumes. A fight broke out, as it does, and I gleefully stomped right through thorn bushes, knowing full well my armor and actual, proper boots can take it, to flank the enemy shield wall. Unless your thorn bushes are some exotic variety with long and durable spikes, anyone with padded armor will be able to get through with a few small nicks in the armor, and anyone in metal will only be slowed down slightly by them.

I disagree. Bushes big and gnarly and tangled DOES stop you - al least for a time. Maybe you have seen different bushes than me. But even in full wintergear where "damage from thorns" is not an issue they do stop you cold. During an archaeologcal excavation we had to uses the big digging machine to clear it. Even that had some issues when it had to cross a 1m heigh dike with bramble (it was a komatsu PC240 digger).

The slowdown is not from "hurt" or injuries, but that is so tangled than you cannot push past it. You ceend to clear it with a weapon, wich slows you down. I think I saw a reference to Roman defenses used bushes/branches in ditches?

[VoxRationis]

I'm trying to generate a map over which the players will travel between a coastal village and the fortress it pays tribute to, some 20 km away, and while it stands to reason that much of the area between the two should be devoted to crop fields, I also want to know how much of their journey will be through settlements, woods, and pastures.

What does a Bronze Age (more like Mycenaean Greece, not Egypt or Mesopotamia) rural landscape look like? How far apart are villages usually spaced? How big are the villages? I have been trying to find good claims on this. I've seen Medieval Demographics Made Easy; obviously, its purview is somewhat later than the era I wish to emulate. It also seems to advocate for a lower population density than the figures given in A Collection of Unmitigated Pedantry's semi-recent series on farming would imply, what with the proliferation of quite small farms cited in ancient China, ancient Rome, and 15-century southern France. (And incidentally, both are much lower than some other estimates of farm size I've seen on this forum, in the "is an acre too much" thread, where people insisted that a farm must be in the range of 80-120 acres to be viable.)

Some setting notes for clarification: this takes place in a Bronze Age society that practices partitioning of holdings between sons, usually leading to the penury of the average farmer and consolidation under large landowners (who often kill second sons at birth in an effort to prevent such partition). Socioeconomic status is flexible but viciously unequal; accidents of birth, death, and available neighboring land can cause a family to rise or fall in station dramatically. Elite males ride horses into battle and fight as archers, so it stands to reason that there should be a fair amount of pasture land somewhere. The landscape has mixtures of rugged hills and lowland areas and is post-glacial. Due to Magic^TM, there is no seasonal variation and crops can be grown year-round in the mild subtropical climate.

[PhoenixPhyre]

1) Depend on climate. Mud bricks will fail unless you a firing them. That requires firewood (it needs quite alot!). Making bricks isn't a short cut to making a wall. It requies about the same time and resources (though it is different resources).

2) I disagree. Bushes big and gnarly and tangled DOES stop you - al least for a time. Maybe you have seen different bushes than me. But even in full wintergear where "damage from thorns" is not an issue they do stop you cold. During an archaeologcal excavation we had to uses the big digging machine to clear it. Even that had some issues when it had to cross a 1m heigh dike with bramble (it was a komatsu PC240 digger).

The slowdown is not from "hurt" or injuries, but that is so tangled than you cannot push past it. You ceend to clear it with a weapon, wich slows you down. I think I saw a reference to Roman defenses used bushes/branches in ditches?

1) Yeah, that was my concern. They can fire bricks, but it's fairly expensive in fuel costs. That's why they prefer packed earth building. It's not a particularly dry climate, especially during the winter. Think Great Plains--hot and somewhat humid (there's a very large inland, freshwater sea not all that far away) during the summer, cold and wet during the winter.

2) And I was thinking of those big, totally tangled bushes that are hard to push past. Not rosebushes, but 3-4 foot high, densely-tangled thorny bushes. The kind that will act as a decent cattle fence, unless they're stampeding.

[rrgg]

Just for the record and to avoid any confusion, "rammed earth" often refers to a specific construction style that isn't the same as sloped, earthwork fortifications like what you'd usually see in early modern bastion forts. It was a somewhat labor-intensive process which involved slowly compacting bricks of earth down to about 50% of their original volume creating an almost stone-like material which was extremely sturdy and definitely could be used for vertical construction, including vertical fortifications.

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


Regarding the simpler sloped earthworks and ditches, they have been used frequently for fortification quite a bit even before gunpowder weapons and seem to have been generally considered fairly cheap and quick to construct if you've got the manpower at least. Earthworks were a frequent feature of iron age forts and settlements, no matter what the period it's pretty difficult to fight across a deep ditch or up a steep slope.

According to vegetius regarding entrenched encampments: "There are two methods of entrenching a camp. When the danger is not imminent, they carry a slight ditch round the whole circuit, only nine feet broad and seven deep. With the turf taken from this they make a kind of wall or breastwork three feet high on the inner side of the ditch. But where there is reason to be apprehensive of attempts of the enemy, the camp must be surrounded with a regular ditch twelve feet broad and nine feet deep perpendicular from the surface of the ground. A parapet is then raised on the side next the camp, of the height of four feet, with hurdles and fascines properly covered and secured by the earth taken out of the ditch. From these dimensions the interior height of the intrenchment will be found to be thirteen feet, and the breadth of the ditch twelve. On the top of the whole are planted strong palisades which the soldiers carry constantly with them for this purpose. A sufficient number of spades, pickaxes, wicker baskets and tools of all kinds are to be provided for these works."

[AdAstra]

1) Yeah, that was my concern. They can fire bricks, but it's fairly expensive in fuel costs. That's why they prefer packed earth building. It's not a particularly dry climate, especially during the winter. Think Great Plains--hot and somewhat humid (there's a very large inland, freshwater sea not all that far away) during the summer, cold and wet during the winter.

2) And I was thinking of those big, totally tangled bushes that are hard to push past. Not rosebushes, but 3-4 foot high, densely-tangled thorny bushes. The kind that will act as a decent cattle fence, unless they're stampeding.

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

Depending, this may offer a little bit.

The use of plants as defensive measures is, while not always preferred, certainly something that happened. Aside from forests grown for defensive purposes in China, hedgerows can be nigh-impassable, with the hedge both contributing to the height of the obstacle and growing into the earthen embankment (often with stone too) beneath, making the whole structure very stable. Even in WW2 the hedgerows were a significant barrier that typically required demolition or tanks, usually modified with blades, to get through with any speed.

Having some particularly tough brush with deep roots growing out the side of the earthen wall should be quite effective at both shoring up the works and slowing any attempt to scale them. Or just use stone facing. Or perhaps even try to get the plants to grow through the stone facing, which should be incredibly frustrating to deal with and equally frustrating to get rid of.

[Martin Greywolf]

The use of plants as defensive measures is, while not always preferred, certainly something that happened. Aside from forests grown for defensive purposes in China, hedgerows can be nigh-impassable, with the hedge both contributing to the height of the obstacle and growing into the earthen embankment (often with stone too) beneath, making the whole structure very stable. Even in WW2 the hedgerows were a significant barrier that typically required demolition or tanks, usually modified with blades, to get through with any speed.

Okay, if you make the brambles thick enough to a point where they stop you be their sheer mass, it will work if it is high enough. Bu thorns will be of limited effect there, you will get simlar effect with hedges. How you want to get them grown in a few months, though... well, I guess you could always claim magic.

Having some particularly tough brush with deep roots growing out the side of the earthen wall should be quite effective at both shoring up the works and slowing any attempt to scale them. Or just use stone facing. Or perhaps even try to get the plants to grow through the stone facing, which should be incredibly frustrating to deal with and equally frustrating to get rid of.

This is a terrible idea and will get your wall to crumble in a few years, damage by roots is quite a problem, even grass can damage a castle wall given enough time. Earthern wall will fare even worse.

I'm trying to generate a map over which the players will travel between a coastal village and the fortress it pays tribute to, some 20 km away, and while it stands to reason that much of the area between the two should be devoted to crop fields, I also want to know how much of their journey will be through settlements, woods, and pastures.

What does a Bronze Age (more like Mycenaean Greece, not Egypt or Mesopotamia) rural landscape look like? How far apart are villages usually spaced? How big are the villages? I have been trying to find good claims on this. I've seen Medieval Demographics Made Easy; obviously, its purview is somewhat later than the era I wish to emulate. It also seems to advocate for a lower population density than the figures given in A Collection of Unmitigated Pedantry's semi-recent series on farming would imply, what with the proliferation of quite small farms cited in ancient China, ancient Rome, and 15-century southern France. (And incidentally, both are much lower than some other estimates of farm size I've seen on this forum, in the "is an acre too much" thread, where people insisted that a farm must be in the range of 80-120 acres to be viable.)

Some setting notes for clarification: this takes place in a Bronze Age society that practices partitioning of holdings between sons, usually leading to the penury of the average farmer and consolidation under large landowners (who often kill second sons at birth in an effort to prevent such partition). Socioeconomic status is flexible but viciously unequal; accidents of birth, death, and available neighboring land can cause a family to rise or fall in station dramatically. Elite males ride horses into battle and fight as archers, so it stands to reason that there should be a fair amount of pasture land somewhere. The landscape has mixtures of rugged hills and lowland areas and is post-glacial. Due to Magic^TM, there is no seasonal variation and crops can be grown year-round in the mild subtropical climate.

It also seems to advocate for a lower population density than the figures given in A Collection of Unmitigated Pedantry's semi-recent series on farming would imply, what with the proliferation of quite small farms cited in ancient China, ancient Rome, and 15-century southern France.

The problem here is the local maximums and minimums - the population desity will not be uniform for a country. Arable lowlands will have more people, tall mountains will have barely any and cities will have high concentrations. Things like gold deposits and major rivers will impact this, as well as stable vs unstable borders and so on and so forth. The more profitable and peaceful the region is, the more population it will usually have.

Spoiler: Major settlements in high medieval Hungary

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You can see the settlements, and therefore population, mostly concentrated in a west to north crescent

And incidentally, both are much lower than some other estimates of farm size I've seen on this forum, in the "is an acre too much" thread, where people insisted that a farm must be in the range of 80-120 acres to be viable.

Viable how? Self sustaining community has 50 people per 2 ha, with very, very primitive farming (fallow cropping with no fertilizer), as per this article. In that sense, yeah, you need 200 ares for a sustainable farming village, but that village has several farms, probably five or so (10 people per household is sort of a standard rule of thumb), and a portion of them does not look like farms (pasture, maybe, depends on how you fallow crop).

Problem is, you can't easily scale it down, just because the math works out to 4 ares per man doesn't necessarily mean one man can sustain himself off of that amount of land. And 50 people is a very small village, any lower and it will probably disappear by people moving out. Villages are usually in the 100-200 people range.

I'm trying to generate a map over which the players will travel between a coastal village and the fortress it pays tribute to, some 20 km away, and while it stands to reason that much of the area between the two should be devoted to crop fields, I also want to know how much of their journey will be through settlements, woods, and pastures.
[...]
The landscape has mixtures of rugged hills and lowland areas and is post-glacial. Due to Magic^TM, there is no seasonal variation and crops can be grown year-round in the mild subtropical climate.

Assuming this is in a relatively stable region, likely all of it. Farmable areas will be concentrated in the lowlands, with hills reserved for pasture. Habsburg first military survey map from 1700s shows us a village every 5-10 km on a road, with road and therefore village network denser in arable areas and sparse in the hills.

[VoxRationis]

The problem here is the local maximums and minimums - the population desity will not be uniform for a country. Arable lowlands will have more people, tall mountains will have barely any and cities will have high concentrations. Things like gold deposits and major rivers will impact this, as well as stable vs unstable borders and so on and so forth. The more profitable and peaceful the region is, the more population it will usually have.

Spoiler: Major settlements in high medieval Hungary

Show

You can see the settlements, and therefore population, mostly concentrated in a west to north crescent

No, I get that factors like the availability of water and arable land tends to affect density; I was asking more about layout within a particular density; a region composed of an approximate grid of ~100-person villages every kilometer will be somewhat different than one with ~400-person villages every two kilometers, despite having the same population density overall.

Viable how? Self sustaining community has 50 people per 2 ha, with very, very primitive farming (fallow cropping with no fertilizer), as per this article. In that sense, yeah, you need 200 ares for a sustainable farming village, but that village has several farms, probably five or so (10 people per household is sort of a standard rule of thumb), and a portion of them does not look like farms (pasture, maybe, depends on how you fallow crop).

Problem is, you can't easily scale it down, just because the math works out to 4 ares per man doesn't necessarily mean one man can sustain himself off of that amount of land. And 50 people is a very small village, any lower and it will probably disappear by people moving out. Villages are usually in the 100-200 people range.

They didn't really say what "viable" meant; I rather suspect a bias towards more modern farm systems in that thread.

Assuming this is in a relatively stable region, likely all of it. Farmable areas will be concentrated in the lowlands, with hills reserved for pasture. Habsburg first military survey map from 1700s shows us a village every 5-10 km on a road, with road and therefore village network denser in arable areas and sparse in the hills.

Sorry, what I meant by that was, "of their journey, how much would be through settlements, how much through woods, how much through fields," etc. I realize that the way I phrased that was not very precise.

Anyway, thank you for the information.

[snowblizz]

Sorry, what I meant by that was, "of their journey, how much would be through settlements, how much through woods, how much through fields," etc. I realize that the way I phrased that was not very precise.

Anyway, thank you for the information.

Roads will avoid woods wherever possible, they are terrible places to put a medieval style road unless the other options are worse. It will also try to avoid water. Around these parts a lot of old roads were following the sand-ridges left by the iceage icesheet as it waxed and waned over the years.

Since the road will likely have been built to service the communities along the way you'd be seeing a lot of them. More than their area of coverage would indicate. So mostly you'd be passing fields and pasture. Fields around the villages which turn into pasture further out and if there's a lot of distance between two villages or the terrain is unfavourable they will have left it as woodland.

In a heavily settled area you don't have forest as such, you have highly managed woodlands. The problem is most of how it would go depends on the geography of your area.

[Martin Greywolf]

Sorry, what I meant by that was, "of their journey, how much would be through settlements, how much through woods, how much through fields," etc. I realize that the way I phrased that was not very precise.

Assuming it's fully settled area and there are no wars to empty it:

• 100% will be on a road, probably dirt, unless you have Roman-style highway
• a village every 5-10 km, the shapes of which will vary, some will be more or less a circle, others will stretch alongside a stream, a village portion can be anything from 100 meters to a kilometer
• for outside, vast majority (80-90%) will be some sort of agricultural land (wheat, vegetables, pasture, orchards, vinyards), small plots (~1 acre) divided by hedges or butts
• the rest will be timber forests, planted and maintained specifically to provide timber, so les undergrowth and a lot of straight growing trees

This isn't a proportion of land, mind you, there is a lot more forest around, it's just that roads tend to avoid them for the most part, and since this is a coastal region, most of the villages will e on the coastline to have access to fishing and ship transport, and will therefore concentrate farmland to the shore and push the forests out. This is mostly due to you having to go to farm a lot more often than go to timber, and the kind of operation that needs a lot of timber (smelting, for one) being concentrated next to forest and deliberately away from housing.

Roads will follow villages, so you're likely to visit every single one between your starting and ending points, unless you deliberately try to avoid them by going via the side roads, which will slow you down, potentially quite a bit. If you try to cut straight through without following roads, you will be slowed down quite a bit and attract angry farmers.

If the area isn't fully settled yet or had a crisis or several recently, you will get some percentage of abandoned land, but what that percentage is depends on political situation - coastlines and river banks are usually first places to be settled at any rate.

Example road:

1. small village A, 130 meters (elongated)
2. farmland, 6 km
3. medium village B, 130 meters (circular)
4. farmland 2km
5. forest 3 km
6. farmland 3km
7. large village C, 1km (runs along a stream)

As a rule of thumb, a 2-3km radius around a village will almost always be farmland, with the upper limit being at about 10km in special circumstances (e.g. farming a fjord), although this should really be determined by travel time, not distance. About double that (4-6km, maximum stay at 10km) goes for grazing areas, and meadows for making hay and straw for animals in winter go all the way to that maximum of 10km. Beyond 10 km, the travel time is so long that anything but dedicated pastures with temporary summer camps is not viable.

Important note - this radius of 3-6-10 km is per village, if you have a village A and village B, they could be as far apart as 20 km without overlap. What you are more likely to see is villages concentrated along a road and having a kind of ellipse-shape to their zones, so you won't ever hit zones 2 and 3 while going on the main road. Terrain will dictate most of this, though.

Of the first two zones (3km farms and 6km pastures), 80 percent will be some kind of farmable thing, the final meadow zone has about 50 percent being in use. The rest goes to the forests, streams and otherwise unusable land. However, even the first famring zone will only have about 10 percent of its area used to actively grow crops, the rest of it being orchards or pastures.

You may have noticed that that gives a given village an area of ~2500 ha in the first zone, 250 ha of which is actively worked for crops. That's a lot more than 2-10 ha needed to sustain a village of 50-200 people, but keep in mind that's the bare minimum for subsistence, our actual villages want to 1) make a profit and 2) have some variety in their diet.

That area of 250 ha needs 1 000 man-hours to plow, which translates to 100 man-days assuming you take a ten hours of plowing a day. While this is hard physical labour, you only need one person strong enough to operate the plow, while driving the animlas can be done by a child. Assuming a household of 10 and traditional gender roles, we can estimate 3 males that can plow (2 being too young or too old) per 10 people. In a village of 50, that's 15, so even in that lowball case, a plowing can be done in a week (although I doubt this would actually be attempted, I have plowed with a small hand-tractor and it's hard, hard work, six days will make everything hurt). A more reasonable village of 200 people can do it in two days.

[Lvl 2 Expert]

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

Depending, this may offer a little bit.

The use of plants as defensive measures is, while not always preferred, certainly something that happened. Aside from forests grown for defensive purposes in China, hedgerows can be nigh-impassable, with the hedge both contributing to the height of the obstacle and growing into the earthen embankment (often with stone too) beneath, making the whole structure very stable. Even in WW2 the hedgerows were a significant barrier that typically required demolition or tanks, usually modified with blades, to get through with any speed.

Having some particularly tough brush with deep roots growing out the side of the earthen wall should be quite effective at both shoring up the works and slowing any attempt to scale them. Or just use stone facing. Or perhaps even try to get the plants to grow through the stone facing, which should be incredibly frustrating to deal with and equally frustrating to get rid of.

As a side note on plants: larger forts and fortified towns apparently historically often had quite a few trees growing in/on them, possibly looking closer to modern "abandoned and overgrown" remnants than to clean cut restorations. Especially ones we start getting to the early modern period, where larger forts and longer sieges become the norm. Not only do plants work as cover for the defenders and obstacles for the attackers, but when you're actually under siege they form a source of firewood and material for repairs. Why only have stockpiles of dead wood that slowly rot away in peacetime when you can have a stockpile of living wood that keeps growing bigger?

[AdAstra]

Okay, if you make the brambles thick enough to a point where they stop you be their sheer mass, it will work if it is high enough. Bu thorns will be of limited effect there, you will get simlar effect with hedges. How you want to get them grown in a few months, though... well, I guess you could always claim magic.



This is a terrible idea and will get your wall to crumble in a few years, damage by roots is quite a problem, even grass can damage a castle wall given enough time. Earthern wall will fare even worse.






The problem here is the local maximums and minimums - the population desity will not be uniform for a country. Arable lowlands will have more people, tall mountains will have barely any and cities will have high concentrations. Things like gold deposits and major rivers will impact this, as well as stable vs unstable borders and so on and so forth. The more profitable and peaceful the region is, the more population it will usually have.

Spoiler: Major settlements in high medieval Hungary

Show

You can see the settlements, and therefore population, mostly concentrated in a west to north crescent

Viable how? Self sustaining community has 50 people per 2 ha, with very, very primitive farming (fallow cropping with no fertilizer), as per this article. In that sense, yeah, you need 200 ares for a sustainable farming village, but that village has several farms, probably five or so (10 people per household is sort of a standard rule of thumb), and a portion of them does not look like farms (pasture, maybe, depends on how you fallow crop).

Problem is, you can't easily scale it down, just because the math works out to 4 ares per man doesn't necessarily mean one man can sustain himself off of that amount of land. And 50 people is a very small village, any lower and it will probably disappear by people moving out. Villages are usually in the 100-200 people range.



Assuming this is in a relatively stable region, likely all of it. Farmable areas will be concentrated in the lowlands, with hills reserved for pasture. Habsburg first military survey map from 1700s shows us a village every 5-10 km on a road, with road and therefore village network denser in arable areas and sparse in the hills.

In areas with significant rainfall, not having plant growth in your earthen walls will cause them to erode without question, unless it's rammed earth or adobe/cob (which will hold up fairly well, but will still be affected over very long periods of time). Curtain walls are a whole different thing, but for the sort of earthworks proposed plants should only be beneficial. Deep roots stabilize soil and are generally speaking, a good idea (though earthen dams can be compromised by woody growth, grass is beneficial). Elevated hedgerows, even those faced with stone that will be more vulnerable to damage from growth, have maintenance cycles on the order of over 100 years, as in Cornish and Devon hedges (though these are farm walls meant for soil protection and sectioning off land, they are very much walls).

[adso]

I'm interested in learning more about the relationship between distance and accuracy with ranged weapons. I'm particularly interested in bows, but anything relating to crossbows, spears, slings, etc would be similarly helpful. I've found a lot on the effective range of various historical weapons, but it tends to be presented as a fairly broad range. I'm wondering, within that range, what is the relationship between accuracy (ability to hit a human-sized target) and distance? Even some anecdotal evidence from someone familiar with a weapon regarding whether it is a linear vs. exponential decrease in accuracy would be great!

[Pauly]

Accuracy is essentially a function of velocity. The more arc you need to get the distance to the target the less accurate you become. There are some confounding variables such as stabilization (spin and/or fins), aiming devices and so on, but velocity is the main variable affecting the device/projectile. Skill of the user is probably higher importance, but I am assuming equally skilled users for this.

Edit to add:
Projectile mass is another factor at longer ranges. Lighter projectiles get affected by air resistance more than heavier projectiles. However I don’t know if man powered projectiles have enough flight time for this to be an important consideration.

[Squire Doodad]

In areas with significant rainfall, not having plant growth in your earthen walls will cause them to erode without question, unless it's rammed earth or adobe/cob (which will hold up fairly well, but will still be affected over very long periods of time). Curtain walls are a whole different thing, but for the sort of earthworks proposed plants should only be beneficial. Deep roots stabilize soil and are generally speaking, a good idea (though earthen dams can be compromised by woody growth, grass is beneficial). Elevated hedgerows, even those faced with stone that will be more vulnerable to damage from growth, have maintenance cycles on the order of over 100 years, as in Cornish and Devon hedges (though these are farm walls meant for soil protection and sectioning off land, they are very much walls).

So a crude mud wall having patches of grass or being studded with ferns would actually make it stronger?

[Gnoman]

There's two kinds of accuracy - mechanical accuracy and practical accuracy. Mechanical accuracy is the ability of a weapon system to hit a target absent any other factor. For this purpose, velocity isn't that important at all. What matters is the weight of the slug (which helps it avoid aerodynamic effects), the mechanical properties of the weapon (how well made it is, and how much error it introduces to the projectiles it launches), and the aerodynamic qualities of the missile - for firearms this is called the ballistic coefficient, and measures how "slick" it is toward the air it is passing through.


Practical accuracy is another matter. Most ranged weapons are much more accurate than the people firing them, and this is where velocity becomes the defining factor - the less ballistic drop you have, the better your hit rate will be. The nature of the weapon itself also makes a big difference. Something like a sling or javelin is going to be much harder with distance, because you basically have to aim it with your entire body. Meanwhile a crossbow, like a modern firearm, will be much more capable of finely refined aim. It will also be much less dependant on the physical state of the shooter - raising and firing a crossbow (though not necessarily loading it) is much less physically taxing than a bow or throwing weapon, and thus will be less likely to experience the effects of physical strain when firing.

As far as distance goes, the biggest thing is that every single negative factor is multiplied the farther out you're aiming. To give a concrete example (albeit one much more modern than you're looking for), a very good rifle will be accurate to "one minute of angle". This means that you can expect the mechanical accuracy of the rifle to place every round within a 1/60th degree cone extending from the muzzle. A rule of thumb to estimate the effect of this is that the base of this cone will be 1" across per 100 yards of range. So, at 100 yards, it will place every shot within a 1" circle - a very nice and precise grouping. Go out to 500 yards, and that circle becomes 5" - not nearly so nice. At 1000 yards, the circle is 10" - approaching the proverbial broadside of a barn. That's just the mechanical effects of the construction. Every factor - slightly off aim, trembles from fear or fatigue, a fly making you blink, whatever - will be multiplied in the same way.

This applies to all ranged weapons. Same reason why a throw from outfield to home base is harder than the same throw from shortstop even if you have the arm for it, or why basketball players usually find free throws much easier than 3-points from the other end of the court.

[halfeye]

Accuracy is essentially a function of velocity.

This is not always true. In the case of the WW2 british 17pounder anti-tank gun, the sabot round was faster, lighter, more likely to penetrate enemy armour if it hit, but less accurate.

The Firefly 17-pounder was theoretically able to penetrate some 163 mm of armour at 500 m (550 yd) and 150 mm at 1,000 m (1,100 yd) using standard armour piercing, capped, ballistic capped (APCBC) ammunition. Armour piercing, discarding sabot (APDS) ammunition could penetrate some 256 mm of armour at 500 m and 233 mm at 1,000 m, which on paper could defeat the armour of almost every German armoured fighting vehicle at any likely range.[11] However, war production APDS rounds lacked accuracy, and the 50 mm penetrator was less destructive after it had penetrated enemy tank armour than the 76.2 mm APCBC shell

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

[Brother Oni]

This is not always true. In the case of the WW2 british 17pounder anti-tank gun, the sabot round was faster, lighter, more likely to penetrate enemy armour if it hit, but less accurate.

Given the mechanics of a saboted shell (the outer casing falling off while in flight resulting in an unstabilised long rod flying through the air), it's not surprising that accuracy and precision are affected; as Gnoman said, the mechanical accuracy of the weapon system is low due to the poor aerodynamic qualities of the projectile.

It's why they progressed to adding fins to the core, resulting in APFSDS which is basically a giant dart.

[halfeye]

Given the mechanics of a saboted shell (the outer casing falling off while in flight resulting in an unstabilised long rod flying through the air), it's not surprising that accuracy and precision are affected; as Gnoman said, the mechanical accuracy of the weapon system is low due to the poor aerodynamic qualities of the projectile.

It's why they progressed to adding fins to the core, resulting in APFSDS which is basically a giant dart.

Yeah, I don't dispute that, I was just pointing out it's one example of the alleged rule not being true.

[snowblizz]

It's why they progressed to adding fins to the core, resulting in APFSDS which is basically a giant dart.

If you ask me it was just an excuse for the British to turn tank-shooting into a pubgame.

[Pauly]

This is not always true. In the case of the WW2 british 17pounder anti-tank gun, the sabot round was faster, lighter, more likely to penetrate enemy armour if it hit, but less accurate.



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

Another problem was that the sights weren’t calibrated for the APDS shot initially, although that may have affected the 6pdr more as APDS was introduced on the 6pdr first. But as I said in my initial post on the subject “ There are some confounding variables such as stabilization (spin and/or fins), aiming devices and so on,”

If you take a level playing field of comparing 2 different APDS rounds fired from the same gun then, all other things bring equal, the one with higher velocity will be inherently more accurate.

[Martin Greywolf]

I'm interested in learning more about the relationship between distance and accuracy with ranged weapons. I'm particularly interested in bows, but anything relating to crossbows, spears, slings, etc would be similarly helpful. I've found a lot on the effective range of various historical weapons, but it tends to be presented as a fairly broad range. I'm wondering, within that range, what is the relationship between accuracy (ability to hit a human-sized target) and distance?

Well, it depends on weapon, ammunition and training a person has. You listed a vastly different amount of weapons there, so I'll address them in turn. I've at least used all of them for a bit.

Note that I'll be glossing over a lot of stuff. Entire libraries have been written on some of these weapons, after all.

Ye olde arc minutes

First, we must discuss arcminutes. It's how you measure accuracy after all.

Imagine a circle with a centre, and two points on it. If you draw a triangle consisting of those two points and the centre, the angle of the tip at the centre of circle will be some number. That number is represented by degrees, and it goes from 0 to 360 for the whoile circle, with 90 being quarter of a circle and 180 a half. Every one of those degrees can be subdivided into minutes and seconds.

So, that's what a minute is.

Now, as you are shooting, imagine yourself as the centre of said circle, the circle being horizontal. The two points are the left and right edges of the target. The angle at your position will be some number, usually pretty small, and therefore represented in arcminutes. If you can consistently land shots inside that target, then that number is your accuracy.

Another way of looking at it is to take your target, inscribe a circle that will have all your hits in it and make a cone with that circle as its base and yourself as the tip. The angle at the tip is your accuracy in arcminutes.

Bows

Are we talking modern or traditional, heavy or light arrows, and waht draw weight? A difference in single factor can throw you quite a lot, and if you combine them? There's a lot of room for error.

Modern hunters using modern bows, with high velocity but light arrows and low draw weights (but high mechanical efficiency) usually list 50 meters as ethical maximum range - that is, beyond that range, they don't want to shoot at an animal because they aren't sure they will kill it quickly and painlessly.

Maximum range of traditional bows is a hair over 500 meters, which was done with Ottoman recurve and flight arrows, and you do have people who can hit a man-sized target at 200 meters fairly consistently. Do keep in mind that at that distance, your first shot is unlikely to hit unless there is no wind, or if you are insanely skilled and can accurately estimate it. Standard archery practice with English warbows was to shoot from one butt to another, where butt is not a bodypart, but rather a small mound of dirt that ran alongside a field - this distance was 220 meters, and the traditional target was a pole of willow wood, ~2 meters high and ~60 cm wide. Assuming a 60cm group, that gets us a 9 arcminute accuracy, which is... pretty good actually, since this was a standard target, and more serious archers can exceed that.

Note that previous paragraph is talking about bows that are very heavy, in the 130+ lbs range, a hunting bow at 50 lbs will behave differently - but ranges may or may not be the same, since it will probably use lighter arrows.

Why not use lighter arrows? Because when it comes to target penetration (especially important with armor), the more of an object's momentum is made up of its mass, the better it penetrates. Meaning a heavier and slower arrow is better than lighter and faster, so long as their momentums are the same.

Even with heavy arrows, the effective range against heavy armor is at about ~100 meters, not because you can't penetrate it at that range, you usually can't penetrate it even point blank, but because it's extremely hard to aim for armor's weak spots on moving targets at that range, not the least because those weak spots keep moving, and flight time starts to be significant enough that you can't easily lead your shots.

Crossbows

I have no idea about modern ones, but traditional crossbows top out at approximately 200-300 meters at best, almost irregardless of whether they are direct draw lightweight 150 lbs, or heavy 1200 lbs cranequin. They fire heavier arrows than bows (usually), and seem to do either a little better or at least comparably to heaviest warbows when it comes to penetrating armor.

There is almost no limits to how accurate you can make one, but the costs of manufacture for the bolts will reflect that. It shoots a lot like a rifle, really, so practical accuracy is "yes" on a man-sized target. Being able to identify the target at that range, especially in heavy terrain, is another matter entirely.

It has the same effective range against heavy armor as the bow, for the same reasons.

Spears, javelins, franciscas and so on

The range on these is about 20 meters from the actual wartime accounts, albeit theoretical top is at about 50 meters. Current Olympic record is almost 100, but you are unlikely to find an Olympic level athlete, with that amount of specialized training and completely unencumbered on a battlefield. Not the least because that distance is well within bowshot, and the archers will be entirely too happy to give you surplus miniature spears they call "arrows".

At that range, provided you have a modicum of skill, you can hit a man easily, and a weak armor spot fairly easily. The reason they weren't popular weapon is 1) bulky ammunition and 2) that distance is not much when the enemy decides to charge you. Still, there were armies that could make use of these, most notably the Romans.

For a more spherically-adjecant objects, like rocks or throwing axes, well, a professional baseball pitcher can reach about a hundred meters consistently. From that we can conclude that effective range will be similar to spears (Olympic record also at about 100 meters), maybe slightly longer, so let's call it 25 meters.

Atl atl

I have absolutely no insights to offer, aside from the obvious "increases javelin range", since I never used it.

Sling

This is a surprising one. Period accounts tell us that it can reach out to 200 meters (according to Vegetius, it's 180 really, but 200 is easier to remember) with stones and 400 meters with lead shot. The 200 meters range is explicitly stated as for training against man-sized straw dummies, the 400 was against a unit of archers. Maximum range is at about 550 meters.

Unlike bows, it uses battlefield ammo for its maximum range shots, but it does have one fatal weakness. Armor.

Or rather, certain types of armor. Research on slings is so sparse it is almost non-existent, but we can say this with some certainty: chain mail of the Roman and early medieval time, worn over thicker tunic, doesn't protect you against slings sufficiently, if at all. Chain mail of high medieval era, with gambeson underneath, offers better protection, but to what degree is uncertain, probably significantly higher, but not perfect. A solid armor, lamellar or plate, on the other hand, damn near nullifies sling's effect entirely.

You can defeat armor with heavier sling ammo - the nubmers above are for 30-50 gram shot, and we know heavier shot of 100-150 grams was used even in antiquity, but your range will go down. Medieval period sees some stones that would clock in at 1-1.5 kg (that is, 1000-1500 grams), but an experiment has shown that your range will be at 40-60 meters at best with those.

There is, of course, the elephant on the room here. Slings are incredibly hard to aim. Seriously. I cannot overstate how much of a pain in the neck they are. I ran some numbers on it, and after 6 moths of rigorous slinging, one hour every bleeding day (680 hours of training), I'm at about 100 arcminutes (so, 1 degree and 40 minutes, really) of accuracy if I don't mess up the release, and I mess up the release about every third shot (which results in the shot going still in general direction of the enemy, but at 20 meters hitting the fourth guy to the left of what I was aiming at). The acceptable accuracy for handgun slef defence is usually given at about 17 arcminutes, with that getting you the effective range of 50 meters.

You can get good with a sling, really good. Balearic slinging competition has its highest range bullseye being a 60 cm circle at 60 meters, giving us a 34 arcminute accuracy, and Vegetius' range of 180 meters against a target about a meter wide at best gets us 18 arcminute accuracy that is historically attested. There's a reason why he says that the people should train doing that daily, though, and we know it wasn't done in practice, at least not on a legion-wide scale Vegetius wanted it to be.

Summary

In summary, all the weapons above can be trained in sufficiently enough that the real limitation becomes your eyesight and targets moving during flight time (for hitting armor gaps at 100+ meter ranges), or atmospheric conditions interfering (at long range shots). Or, in case of thrown weapons, are short range enough that none of it matters.

For practical accuracy, crossbow is like a rifle, you point (at or above the target) and shoot. Looking at accuracy of rifles with ironsights and accounting for slower projectile flight time will get you a good idea.

Bow is a tad harder. You can sight down an arrow just like with crossbow, but you can't do it in a relaxed state, or for too long. You can achieve comparable accuracy, but training for it takes longer, and fatigue will affect you more.

Thrown weapons have nothing to sight down, and are therefore significantly harder to aim, but compensate for it by means of short range.

A sling is literally the worst. Not only does it have nothing to sight down, like throwing weapons but without the mercy of short range, it also lacks the immediate tactile feedback of a thing you hold in hand. You can learn to compensate for it, but not easily, and definitely not quickly.

The feeling when you nail your steel helmet at 20 paces with a slung baseball and make it clang loudly is pretty great, though.

Even some anecdotal evidence from someone familiar with a weapon regarding whether it is a linear vs. exponential decrease in accuracy would be great!

As a ballpark, and very rough one at that, it's linear for every factor of: distance, target movement, wind (at greater ranges only). Your accuracy technically stays at N arcminutes, but all of these three affect where your point of aim must be.