Night Clerk of the Apacalypse.
Somber: Source for what armies traveling exceedingly long distances just for one city? Jerusalem ring a bell? How about the French in Portugal? Not exactly friendly shores and Portugal and Spain alike had very heavy partisan activity. The French under Napoleon were not the first to do that.
A well known issue of supplying an army in the field laying siege? The old saying is old for a reason. An army marches on it's stomach. Quite a few armies have had to withdraw from a siege due to dwindling supplies. One of the Mongol sieges had to be broken off because they were running low on supplies and they were loosing men to the plague.
Who watches the watchmen?
Diverting a river using medieval means would require years if not decades of work...and somebody with the know-how to plan the whole thing, which could be a lot harder to find than a few thousand workers.
Damming a decently-sized river using those same means is just plain out of the question. A civilization with rome-level infrastructure could maybe pull it off on their own territory, if enough of the entire civ's resources are made available for the project, but definitely not with a besieging army.
![[up]](https://static.tvtropes.org/pmwiki/pub/smiles/arrow_up.png "[up]"){kind=icon}
Diverting a river is HARDER. You build a causeway into the ocean, the ocean doesn't have to go anywhere but a little to the left or right. Sure, currents might make things difficult, but once the currents are cut off the ocean doesn't overflow the shore. When you build a dam, all that water has to go somewhere. I remember reading one story where, in order to take a castle on a small island in the middle of a lake with a narrow outlet, the besiegers used landslides to choke the river, raise the lake level thirty feet, and flood the castle's stores. When the defenders surrendered, they broke the dam, let the water drain out took the castle and the riches and paddled home. Not bad for a bunch of farmers against armored troops.
Thank you for providing specific examples. From what I read, Napoleon was able to march an army to Lisbon because the Portugese utterly capitulated. The partisan activity you speak of happened AFTER the occupation of the Iberian peninsula, when British agents started to poke holes in the myth of french invincibility. (Also a lesson: do not disband the armies of your occupied countries. Pay them better than their former masters did.) Jerusalem and the Crusades is a better example, I admit, most particularly the first Crusade; the only one that was ever successful. Still, the challenge was not so much capturing Jerusalem as it was getting there.
Add to the fact that if you divert a major river, particularly if that river is the city's main source of water, you've just effectively destroyed the city. Rivers are major components in a city's function. Without the flow of fresh water, salt water begins to permeate the ground and spoils wells. Sewage may no longer be carried away. Garbage accumulates and soon the city is uninhabitable. What's more, once you divert a river, there's no guarantee that you can divert it back!
edited 22nd Nov '13 6:11:21 AM by Somber
edited 22nd Nov '13 10:28:08 AM by MattII
Maybe I'm mistaken, but my understanding was that it's actually fairly easy to dam a river, so long as you don't mind if the dam collapses after a few days.
More like a few hours and even then it better be a small river. The biggest challenge is that the more you dam up the river the more pressure the river exerts on the damn. Unless you use magic to create the dam instantly the water runs faster and faster the more you constrict it. This leads to you're building material being washed away before you've finished. What you need to do is cut a channel to divert the weight of the river elsewhere so as you build the damn the water flows down the channels. The channel is a technical challenge because you need it to slope downwards uniformly through it's entire length or it'll clog at the drop of a hat.
Just to give you a sense of scale, the Thames river that runs through London has a flow rate of 65.8 cubic meters per second. That works out to about 14,000 gallons every second (rounding down). That works out to about 116,000 pounds of water added behind the damn every second.
Welcome to civil engineering. Here's you're calculator and you're alcohol.
Zzzzzzzzzz
If you are trying to make something that will last for an extended period of time with minimal ongoing upkeep and which will divert the water along a specific course, then yes, it's a big project and it needs to be carefully planned and executed.
If all you're concerned with is making the water go somewhere else for a while, and you don't much care where it goes, it's not really that difficult. Just dump sufficient stuff in the existing course fast enough and it'll do it.
Look at what a single big tree branch going into a stream or small river can do in a flood. The branch alone isn't enough, but as more stuff comes downstream and gets hung in the branches, you get a pretty effective dam pretty quickly, with no planning or engineering at all — just happenstance.
...if you don’t love you’re dead, and if you do, they’ll kill you for it.
I've seen branches fall into rivers and it's only the most shallow rivers and streams can be diverted as such. Furthermore, even with a mass of material in the river, a river tends to stay within it's banks. Older rivers cut their own bed which often becomes the lowest part of the land. Even if you can divert a river it likes to run right into it's old bed. A river may meander but that often takes years and several hundrend tons of soil.
Citizen
You got an army, armies dig trenches, rebuttments, latrine pit. Start with regular trenches, then dig closer and closer to the river. Some of the river is diverted. City has a smaller water supply.
You have an army, a couple of turds in the river won't poison the water supply, lots of turds and diseased corpses in a reduced water supply...
OP introduces, more explanations: In the first version, Gangs beat soldiers with such a Curb Stomp that the City Council decides that this shall be the standard military tactic. Invaders pwned the Refugees, so they ran away to the City and now Invaders follow them. Gangs have double incentive to fight Invaders.
But with new info, Qarth is a super-dooper naval Power. Invading army getting there was a fluke, which fits the fluke of gangs defeating Soldiers.
Refugees are Free-born Citizens??? That breaks the City of Adventure theme you set up in OP.
Standard military tactics with a City Wall = set up a clear killing field and destroy any trees and houses that will give cover to Invaders.
But now the Refugees are Free-born Citizens, they live in Qarth proper and do Militia duty. The adobe sub-urbs are left there because it is useful for the Gangs' fighting style.
OP's first plan was better: Refugees are promoted from nothings to 2nd class Citizens. They still gotta live in the Shambles suburb, but Shambles is a living, breathing City with each Gang Captain as feudal overlord of his turf.
""Just to give you a sense of scale, the Thames river that runs through London has a flow rate of 65.8 cubic meters per second. That works out to about 14, 000 gallons every second (rounding down). That works out to about 116, 000 pounds of water added behind the damn every second.""
Cubic meter of water = 2,200 British pounds, 66 cubic meters ~ 140,000 British pounds. USA pint is different from Brit pint, but I thought USA pound was the same size as Brit pound.
edited 22nd Nov '13 1:43:27 PM by Jaqen
What if there were no hypothetical questions? There are 10 kinds of people: those who understand Binary and those who don't.
I'm not planning on having those sorts of class distinctions. The society will certainly have old money families and people disenfranchised by the system, but no official aristocrats or underclasses.
Night Clerk of the Apacalypse.
For building large dams as defenses. I think it was the Siege of Badajoz that the French damned up a small river and created an artificial lake blocking off an approach to city.
If not Badajoz it was one of other particularly nasty cities to take.
Something else to remember about the French in Portugal. While they did have baggage and supply trains the military relied heavily on foraging of off the land.
Part of Wellingtons strategy involved snatching up as much food and supplies as they could carry with the army and the retreating civilians to the lines of Torres Vedra and destroying the rest.
The French sieged the lines but the lack of food and hard winter killed off quite a few of them. As soon as spring hit they were forced to pull back.
For a long time getting any supplies in the winter was fairly difficult. Snow made travel more difficult and slow going as well as provided hazards for those traveling. Mountain passes were frequently blocked by winter snows.
Now in warmer climates that might not be as big an issue because you don't have to worry about the snows but other things like tropical storms and other weather features may provide hardships and challenges. Like for example torrential rains often wash out roads, turn once stable ground marshy thick mud, etc.
Who watches the watchmen?
Citizen
I'm not planning on having those sorts of class distinctions. The society will certainly have old money families and people disenfranchised by the system, but no official aristocrats or underclasses.
1st plan was better. If the Refugee hobbits earn Free-born Citizenship and live in Quarth City proper. then they only go back to the Suburb slum Shambles, to set up a FAKE City of Adventure Mas Kerade. If the City Council pays the Hobbits where is the saving money?
If Refugees are second class Citizens then Shambles sub-urbs is a living city.
What if there were no hypothetical questions? There are 10 kinds of people: those who understand Binary and those who don't.
They live in the slum suburbs because living in the city is expensive, and most of them are very poor.
Two points to add to this discussion:
The first is a bit of a rebuttal to an argument that I've seen a couple of times in this thread, that unless they are given full citizenship, the slum-dwellers won't fight (or at least not to the death). My rebuttal to this is that such an idea is more of a modern concept: peasants where rounded up to fight all the time (in England, for example, weekly archery practice was mandatory for all male peasants from late childhood until old age. They even banned golf in Scotland at one point because its popularity had eclipsed that of archery), and none of them had much in the way of citizenship rights.
The second, and more constructive point is that this city-state would probably be a bit different from "middle ages classic", due to a few reasons: -It's a city-state, and thus small, rather than a (presumably larger) feudal country; thus it does not neccesarily need a legally defined class system. It might have one, but historically, a city-state's class system would be more aligned with wealthy and/or guild position than noble lineage. -It's diet is probably based on the sea, either through trade or fishing, rather than agrarian farming; thus, there is no need to keep a large group of peasants or serfs "chained" to a piece of land to work it. Instead they could derive income from the shipping trade, either as sailors, or in any of the myriad of support industries that ships need (calking, sailmaking, ropemaking, woodworking, etc.) -It's strength is invested in naval power (ships), rather than terrestrial power(mounted knights).
This also leads to a question to the OP: what kind of ships are this city-state using? Oar-powered galleys? They're rather man-power intensive, so the occupants of the slums may not be so abjectly poor, both in terms of money an political power. Historically, Athenian rowers actually won rights for the poor, non-Hoplites through their military service.
Are the ships sail powered? While less manpower is required, its still somewhat manpower intensive, and the distinction between commoner sailor and noble sailor is diminished, making it a source of social mobility.
All in all, a very interesting city-state, but one that doesn't actually have to be so "classically middle ages" in its social construction.
EDIT: Going back to the 'actual' topic, the slums, I think they also have an advantage of reputation, if nothing else. Medieval sieges were hard enough as it was, with a less than 50% success rate. The fact that the city has port access and is nigh un-blockadeable due to it's naval power means that it would be even less like to fall (since most successful sieges merely waited out their opponents supplies, and starved them into submission). So even if the slums don't actually work, the fact that the city-state probably never fell to siege, and attributes this to the slums means that adversaries probably think that the slums are a force to be reckoned with.
Nihil assumpseris, sed omnia resolvere!
However, a sufficiently large, determined and methodical enemy could potentially divert a reasonable-sized river (something along the lines of the River Tay at Perth), given say, six months. This would have the advantage of robbing the city of much of its drinking water. If that's too much, you could maybe do as Jaqen suggested, and partly divert the river, and then attempt to ruin the remaining water flowing into the city.
edited 24th Nov '13 12:10:53 AM by MattII
Again, you have no idea what you are talking about. Without knowing the specific geography and morphology of the river, this is moot speculation at best. If this river is of any real size, daming or rerouting it is not going to be accomplished by an invading army. Building a dam takes energy, time, an insane amount of man power, and terrain conducive to such. If you provide a shorter route to the sea, and it is in any way shorter and steeper than the original channel, it will be even harder to return the river to its original course. All that water is going to go to sea, and in the process it will flood whatever it can however it can.
I suddenly had an inspiration for an abandoned city in the middle of a swamp.
I dunno. You're already set to sit around for six months or more. Why not mess with their water supply? toss some rotting corpses in. Add poison. Send an oil soaked raft down river and set it on fire with arrows.
Actually, the river might be the best bet to get into the city. Sail down the river into the town then fight your way to the gates and open them. If the river has a grate then toss lumber and other junk in it. This will form a clock in the grate and will divert the river around the walls rather than into the city. Those in the slums may still get water but the city it'self will not.
I don't think they would use the river as a water supply, they would probably not even use it for baths. People would drink beer, failing that they would drink ground water from wells. A medieval slum would quite literally produce tons of shit and almost all of it would end up in the river.
^ And prone to disease outbreaks like cholera. It's well documented throughout history that cities with inadequate drainage would eventually succumb to frequent disease outbreaks. Water wells or not.
It's postulated that the rise of beverages such as beer, wine and tea came about because of an early understanding that water may not be safe to drink on its own.
Citizen
Mongols raided Shire.
Surviving Hobbits ran away.
Hobbits built Shambles slum Suburb outside Qarth.
Mongols raid Qarth.
Hobbits pwn Mongols = Dothraki.
City Council declares Hobbits to be Free-born Citizens.
City Council lies, Senate wants Hobbits to stay in the Sub-urbs and organize defence,
What if there were no hypothetical questions? There are 10 kinds of people: those who understand Binary and those who don't.
@Matt
Alexander's land bridge isn't an apt comparison. For one, it was a bridge, not a damn. It didn't have to contend with water pressure trying to push right through it. The land bridge also didn't need to be water tight. From what I understand, Alexander just threw more and more stones into the strait to form the basis of the bridge. As such, the bridge was porous and even the local currents wouldn't have built up against it. A river has a current to deal with. That current builds up against the damn and if you don't do something with it the river overpowers the damn, either overflowing it or destroying it. The majority of damns aren't designed to stop the water entirely. That would be like pushing back the wind or plugging up a volcano.
As for the siege of Alesia? That was the Romans. Their prowess for engineering wasn't match for hundreds of years. Furthermore, those trenches are tiny compared to a diversion channel you'd need to redirect a major river. Those trenches also didn't need to be cut under the water line so the ups and downs of the terrain aren't a factor.
@m8e
Not that close to the sea you're not. Salt water would get into the ground water which would make it useless for hydration. Beer alone will actually dehydrate you. You need to cut it with water and let the alcohol do it's thing. This was known as small beer. There's also the logistics of importing a city's ENTIRE WATER SUPPLY by ship.
