Let's Talk about Metallurgy / Alloys

[{sBc} Bane5]

So on the roadmap, we have vague mentions of an upcoming metal overhaul. Against the storm also seems to be a world that is still in the copper/bronze age (iron smelting is a completely different beast in terms of production chain complexity and difficulty). Sticking to copper as the primary metal is good--its a lot simpler.

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So a bit of history: there were seven metals known to antiquity:

- Copper
- Tin - (rare and often not found in the same geographical location as copper)
- Iron - (seen as a useless nuisance that ruined copper smelting in the bronze age)
- Gold
- Silver
- Lead - (overabundant waste product of silver smelting)
- Mercury

There were also a few metals/semi-metals commonly used, but they were unknown--only manipulated as ore or in mineral form:

- Arsenic
- Antimony
- Zinc
- (honorable mentions bismuth in south america, nickel in china for copper alloys)

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So for thousands of years after discovering copper, humans made copper-alloy bronze using arsenic and to a much lesser extent antimony. Arsenic bronze has a vickers hardness not too far off from tin-bronze. The main problem with arsenic is that its extremely toxic. With an extremely low melting point compared to copper, your smelter would be spitting out toxic gas fumes that would accumulate in the human body with dire health effects (think of Hephaestus, the lame Greek god of smithing). But this is a fantasy world and perhaps some critters aren't as vulnerable to arsenic....

The reason I bring this up though is because some of the ores/minerals are very flexible when it comes to the production process (production flexibility is a staple of Against the Storm's design). Of particular interest are three sulfosalt minerals:
Tennantite - Cu6[Cu4(Fe,Zn)2]As4S13
Tetrahedrite - (Cu,Fe)12Sb4S13
Freibergite - (Ag,Cu,Fe)12(Sb,As)4S13

Often found together you have everything in there: iron, zinc, antimony, copper, arsenic, silver, and gold. Copper was the main metal of interest and sometimes ancient metalworkers would find that their smelted copper turned out much better than usual because it just so happened to have the right amount of zinc, arsenic, or antimony mixed in (or you got unlucky and produced terrible brittle iron-copper matte if the temperature wasn't just right). You could also cement or heap leach this ore to try and get good quantities of silver or gold instead. Arsenic-iron speiss could also be purposefully produced and then mixed with copper to make bronze (the eventual technique perfected to consistently make arsenical bronze).

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What does gameplay look like?

A simple system in-game might be having a few specific ores:

1). Copper Ore (only oxides, ancient copper sulphide smelting was way more complex if we wanted a blast furnace and silicate flux also)
2). Sulfosalt Ore (arsenic and antimony impure copper blended together)
3). Tin Ore - (copper and tin are never on the same embark, trade for it just like antiquity)
4). Calamine - (this was the only known ancient mineral of zinc)
5). Precious Metals - (makes trade goods)

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[Copper Ore] makes copper
[Tin Ore] makes tin
[Sulfosalt Ore] makes copper
[Sulfosalt Ore] makes bronze inefficiently by itself
[Sulfosalt Ore] makes precious metals
[Sulfosalt Ore + Copper Ore] makes bronze efficiently
[Calamine] makes cosmetics for your harpies
[Calamine + Copper Ore] makes brass
[Tin Ore + Copper Ore] makes bronze
[Tin Ore + Sulfosalt Ore] makes fine pewter
[Tin Ore + Calamine] makes solder
[Precious Metals] makes trade goods
[Tin Bars and Copper bars] can be combined to make bronze

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We should also have a new building called a "Cementation Furnace" it produces a 3-star brass recipe. It also extracts precious metals from sulfosalt ore.
2 parts copper, 4 parts calamine, 1 clay pot, and some fuel would be a recipe for calamine brass. A kiln also works for a 1-star or 2-star alternative.

The Tinkerer building should also be repurposed. "Tinkerer" derives from "tin-maker" as a guy who went around repairing or peddling tin or pewter objects. Let your imagination run wild with that.

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A lot of these alloys would be interchangeable in most recipes, but might be picky in a few cases. You might need bronze specifically for infused advanced tools. Solder or brass might be necessary for anti-corrosive pipes. Tin and Pewter might make metal pots and vases. And so forth.

There's a lot of ways to do a plausible metallurgy system that isn't too large; just thought I'd start a conversation on it.

[Alexander]

A very interesting idea. However, I don't understand references to antiquity. The Smoldering City is a highly technologically advanced civilization.

[{sBc} Bane5]

Originally posted by Alexander:

A very interesting idea. However, I don't understand references to antiquity. The Smoldering City is a highly technologically advanced civilization.

My impression was that it was kind of a post-apocalyptic techno-magic society. Things have greatly regressed since the storms came. There may be some advanced tech, but its all locked away/kept secret by the upper echelons of government for means of control. The average person lives a very humble lifestyle economically and technology.

If there's an in-depth lore section that was posted somewhere, would love to read it.

[Alexander]

It is all true, but the general vibe suggests that they probably didn't regress so far as to lose ability to work iron. There may be other limiting factors, but they probably have nothing in common with the factors that defined the metallurgy in our world's past.

[{sBc} Bane5]

Originally posted by Alexander:

It is all true, but the general vibe suggests that they probably didn't regress so far as to lose ability to work iron. There may be other limiting factors, but they probably have nothing in common with the factors that defined the metallurgy in our world's past.

Iron smelting though is extremely sensitive to even the smallest % of impurities. Since it rains all the time, most of what they have to work with on a seasonal basis is probably low-quality bog iron.

You also need the right kind of charcoal to smelt iron--the right mix of hardwood and softwood. And the trunks of trees aren't that suitable. You wanted the thin branches. And you needed equal weight in charcoal and iron typically. Let me point out that iron is many many times more dense than charcoal so you're shipping huge carts of it for just a little bit of iron. Oh and this high-grade charcoal for smelting only has 10%-15% efficiency when you produce it by burning wood, so you'd be chopping down an entire forest to support one small smelter. (yeah it was that hardcore in deforesting everything)

We need this charcoal for infusing carbon itself, not just a heat source. Still it is many more times more energy intensive as the melting point of iron is way higher than other metals typically smelted. The more modern puddling process for coke came much, much later. Fungiwood is probably completely unsuitable in terms of chemical composition.

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Then there's also the question of how they make their steel? Do they start with a low-carbon piece of iron and try to bring it up to 1.5-2% carbon (think bloomery/cementation process)? Do they start with a pig iron (4+%) and try to bring it down to 2% (think blast furnace/decarbonization kiln in ancient China)? Do they take a low piece of low-carbon iron and a piece of high carbon iron and fuse them together (think damascus steel in india)? Lot of different intermediate products, suitability for applications (casting vs forging), and additional ingredients needed (calcium carbonate, nitric acid, etc) depending on method/ore quality used.

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Cutting corners on a lot of these steps results in a poor-quality spongy material. It was basically an art form and every master smelter developed his own home-brew recipe based on the peculiarities of his smelter, the iron ore used, the impurities in the soil and charcoal, the mineral flux available, etc. What worked in one place would actually completely fail in another. A lot of the iron produced might actually be inferior to bronze because of difficulty in keeping the right impurities out in this rainpunk world--as was the case initially during the switch from bronze to iron making.

[{sBc} Bane5]

But let's say we include some kind of basic representation of iron smelting. The main issue is: there's a lot of ways to do it, but they do not crisscross easily if you want flexible production. The ingredients are different, and the buildings/furnaces required are extremely specialized compared to everything else. Bear in mind that the melting of point of iron is ~2,800°F, whereas for copper its ~1,984°F. We don't need to reach the melting point of iron to smelt it, but we need much higher temperatures than your typical run of the mill charcoal pit smelter used for the other metals.

The good news for iron is that its basically everywhere. Iron is the fourth most common element in the Earth's crust. The entire rainpunk world is basically one shallow swamp, and thus you'll be able to find all the bog iron in peat soil and sift through black sand with a magnet as much you want. Its not the best quality nor the cheapest way, but its there if you're determined to go through with it and don't have rich deposits locally available (and some cultures/regions stubbornly did just that).

When it comes to richer iron ore, what we're looking for are types of iron that decompose easily into "Wüstite" (FeO) while being heated. In a high-temperature bloomery, this would be the final stage of decomposition before you get elemental iron. Most mineral iron-oxides do this in one step, but a few might need an extra stage. In-game we might simply distinguish generically between "rich iron ore" and "poor iron ore" as generic categories for deep mines vs just taking iron from bogs and black sand.

Now there also exist iron-sulfides. Sulphur and phosphorous are the mortal enemies of iron ore smelting. Even just a tiny fraction of a percent can can make your iron ore product completely unworkable. But you can technically take an iron-sulfide and roast it in an environment easily exposed to oxygen to make Wüstite. Its a painstaking process as you have to be thorough, and its an energy intensive step, but its doable. People didn't do it simply because there's just so much better iron-oxide ore out there in abundant quantities.

But I bring this up because in particular, because for example you can take arsenopyrite (FeAsS) and have a choice between making iron ore out of it by roasting in an oxygenated environment vs roasting it a neutral atmosphere (i.e. while buried in sand) to make iron-arsenic spiess for bronze. (this is if we wanted any type of cross-compatibility between metal types). Its probably more valuable to try and heap leach it for small amounts of gold impurities though.

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You might be able to get around some of the design issues by saying that iron is the default omnipresent available metal and give players the highly specific blueprint buildings automatically at the start of the game.

[ulzgoroth]

Yeah, I'm not sure how you're making out that iron is that big a problem. Yes, it takes a lot of charcoal (which we already can make in the game, in a historically atypical way) and...uh...not really much else special. Forced aeration of the bloomery possibly, but that's well handled in AtS tech.

(Of course, as is common in low-tech builder games, AtS has a lot of things that are clearly made of metal but don't require you to have metal production chains because they want metal to be advanced.)

[{sBc} Bane5]

Originally posted by ulzgoroth:

Yeah, I'm not sure how you're making out that iron is that big a problem.

If we just stick with small-scale bloomery wrought iron for simple basic toolmaking, its not complex.

But if you want to make large metal objects (like giant pipes for blightrot), you're going to want cast iron which is completely different in composition. But cast iron shatters extremely easily, so good luck trying to make tools out of it. We need two specialized furnaces: a blast furnace for pig iron, and a cupola furnace to make white iron out of pig iron. Various fluxes are also needed. You can also have a finery hearth forge (this is really special because it actually does a full 100% melt of iron) to convert pig/white iron into wrought iron in mass bulk production. For some advanced applications that require both casting and cold-working, you will need to convert white cast iron into malleable blackheart iron as well (likely some sort of basic kiln). Blackheart iron is suitable for hand tools like wrought iron, but when it comes to making steel, the process isn't the same (high-carbon vs low-carbon). If we want anti-corrosive steel, spring steel, weapon-grade high-carbon steel, etc for machinery and especially high-pressure boilers, then the production chain web gets increasingly complex.

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The main issue here is that with the blueprint randomized system, it might feel bad if you had a Cupola Furnace or Finery Hearth but couldn't use them because you never managed to roll a blast Furnace. Likewise it'd feel terrible to have a blast furnace to produce useless pig iron, but you never managed to get a cupola furnace or finery hearth to make an actually usable product.

For flux, the main issue is that we don't differentiate between various types of stone that we mine. We just have "stone" but we need special kinds. We could just say that the calcium-compound sea-fossils we mine can be used as flux (its a big stretch, but its ok for gameplay purposes).

Originally posted by ulzgoroth:

(Of course, as is common in low-tech builder games, AtS has a lot of things that are clearly made of metal but don't require you to have metal production chains because they want metal to be advanced.)

Well something to ponder is, should this trope be subverted? Have ironmaking right off the bat, but need advanced metal supply chains only for specialized or large-scale applications (like pipes, gears, high-pressure boilers, machinery)?

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Looking at pictures of a lot of AtS building, we do have iron rivets and nails visible on things that do not require metalworking. Should we have people make simple wrought iron nails in a bloomery alongside the typical cloth, bricks, and lumber?

[Scout]

You have to keep in mind this is not factorio. A highly complex and realistic production chain (or requiring buildings to have realistic construction costs -- like a woodcutter camp clearly has wood in it, but all it uses are a few gears to construct) in a game that you play for half an hour isn't fun.

The most complex chain we have is basically gather 1 or 2 raw materials, then make 1 or 2 refined products (jars, flour), and then a finished product, and half the time you already can't complete a chain based on what blueprints you receive and what products are available on the map. I think that's about the right amount of depth for a production chain considering the RNG elements in this.

[{sBc} Bane5]

Originally posted by Scout:

.... and half the time you already can't complete a chain based on what blueprints you receive and what products are available on the map. I think that's about the right amount of depth for a production chain considering the RNG elements in this.

At some point if the devs want to keep adding buildings and new goods, they will have to redo the blueprint system. As the number of buildings goes up in total, the RNG becomes increasingly unbearable.

A good compromise might be to let players roll for buildings in a certain category. Like "I want choose a random farm/food building" or "I want to roll for city building/temple/marketplace" or "Let me roll for a metallurgy building." It'd scale better imo.

[{sBc} Bane5]

EDIT #2: Actually after giving it just a little more thought, this might be much better:

https://steamcommunity.com/sharedfiles/filedetails/?id=2933751802

Multiple pathways now to get to the final product. Most efficient path would be to have a blast furnace for pig iron, finery hearth to turn pig iron into wrought iron, and a wind furnace to fuse both of them into steel during monsoon season.

No need for cast iron as a seperate ingot; you just say that the cupola furnace produces pots/pipes, etc from a mould directly (which is true).

[Lukker]

Wow, this is certainly something. First of all kudos for your efforts here to make a more complex system. Though I think the one in the diagram above is still going a little overboard, then again maybe it just looks more confusing this way than it would be in game.

Some more specific things regarding the diagram:

Some of these steps necessitating Sea Marrow ('Sea Fossils' in the diagram) sounds problematic to me given that not every enviroment contains nodes of it, that also sounds a bit too expensive if it needs fuel in addition. You also mentioned that tin and copper would not appear on the same map, requiring trading instead.
I don't think trading should be an obligatory part of any production chain (especially since the 'Deserted Caravans' cornerstone exists), either Sea Marrow and tin would have to be optional or the end product would need to be completely substitutable similar to how it is with copper and crystallized dew at the moment.

However, I do like the idea of more buildings (other than farms) working depending on the season, the 'can only work during certain season' is perhaps a little too strict and static, though (maybe the efficiency could change depending on season but I'd like something more elaborate).

I'm also a little confused by the inclusion of sparkdew here, given that it was removed from the game in the recent update. As it appears here, this would just make it a resource with only one - very specific - use; which was the reason why it was removed in the first place.

[{sBc} Bane5]

Originally posted by Lukker:

then again maybe it just looks more confusing this way than it would be in game.

In a nutshell, copper-alloys would be the easy production chain. Iron as your primary metal would be the complicated, but ubiquitously available one.

Originally posted by Lukker:

Some of these steps necessitating Sea Marrow ('Sea Fossils' in the diagram) sounds problematic to me given that not every enviroment contains nodes of it, that also sounds a bit too expensive if it needs fuel in addition. You also mentioned that tin and copper would not appear on the same map, requiring trading instead.
I don't think trading should be an obligatory part of any production chain (especially since the 'Deserted Caravans' cornerstone exists), either Sea Marrow and tin would have to be optional or the end product would need to be completely substitutable similar to how it is with copper and crystallized dew at the moment.

A lot of materials are suitable for flux. Its just that sea marrow is the only thing vaguely representing it that we have in-game right now.

Arsenical-bronze (similar strength), brass (anti-corrosion), and white cast iron (having a casting metal) alloys would be the alternate pathways for a lack of tin/pewter for different applications. Crystallized dew could just plug any gap that forms in whatever final production web gets implemented.

Originally posted by Lukker:

However, I do like the idea of more buildings (other than farms) working depending on the season, the 'can only work during certain season' is perhaps a little too strict and static, though (maybe the efficiency could change depending on season but I'd like something more elaborate.

Well for a wind furnace, you could say that it produces pig iron during the calmest season, wrought iron during the drizzle season, and steel during the storm season depending on how fierce the wind would be. Might be a bit overpowered compared to all the others.

Originally posted by Lukker:

I'm also a little confused by the inclusion of sparkdew here, given that it was removed from the game in the recent update. As it appears here, this would just make it a resource with only one - very specific - use; which was the reason why it was removed in the first place.

I last played just before the rainpunk update, I guess I am bit behind. But just vaguely be aware that there are chemical methods of purifying impure iron ore through various means.

[Olleus]

Originally posted by {sBc} Bane5:

A simple system in-game might be having a few specific ores:

This might be simple compared to the real world, but it's probably still waaaaaay too much detail for a game like this. I mean, there's only 1 type of wood, despite all the various trees in the game, and the fact that real world woods have drastically different mechanical and flammable properties. And wood is THE primary resource in the game. Or to take another example, the game just has clothing, not trousers, hats, shirts, shoes, socks, and coats. Settlements last years, but there's no modelling of villagers dating or having to look after kids (the closest to that is harpies and lizards hatching as adults from the eggs you eat - horrific now I think about it lol).

The game has two things that are used as metals: copper bars and crystallised dew, and neither are close to essential. Both of these are made by processing an ore (copper ore in one case, one of the three waters in the other) with another resource. Both are essentially interchangeable in most cases, but not every where. That seems about the right level breadth with about the right level of abstraction. Maybe, at a stretch, there's room for a third? But it's hard to see what it could do that wouldn't be redundant. Do we really want yet more clutter in the game with dozens more resources and recipes? Would it actually do anything for the game other than adding more stuff for the sake of it?

Don't get me wrong, I don't think it's a bad idea. I just don't think that *this* game would benefit from going so in-depth in metallurgy. If you do want to represent different ores and smelting processes, then that could be done more subtly. Give different nodes of copper ore different bonus resources (that's how different trees are represented). Or have copper related perks & cornerstones named after some particular type of ore or processing technique that is an improvement over the default (a cornerstone is the only representation in the entire game of something as universal as furniture).

[Raptor Jesus]

Last thing this game needs is 5000 different resources.

[{sBc} Bane5]

Originally posted by Olleus:

Do we really want yet more clutter in the game with dozens more resources and recipes? Would it actually do anything for the game other than adding more stuff for the sake of it?

Well the thing is, at some point you master the web of production in your head, and then the game becomes simple. Been twiddling my thumbs after beating P20.

Maybe we need some sort of difficulty level settings to ease people into more materials and production processes as they get better and more familiar with the game.

Originally posted by Olleus:

Settlements last years, but there's no modelling of villagers dating or having to look after kids (the closest to that is harpies and lizards hatching as adults from the eggs you eat - horrific now I think about it lol).

Yeah the inequality is outrageous. We should be able to make soylent green out of humans and beavers as well...