TL4 Without Iron

[DanHoward]

Originally Posted by Sindri

One thing I'd be interested in hearing about; Does TL4 offer any ways to extract copper and tin that TL1 couldn't get to? Not just improvements in ease or profitability but actual increases in potentially accessible metal?

There aren't any noticable improvements in mining technology from the Roman period until the Industrial Revolution. There were advancements in smelting technology - you'd probably be able to recover 10-20% more metal from ore using late TL4 smelters compared to earlier ones.

[DanHoward]

Originally Posted by Sindri

This is really just an attempt to grasp how bronze behaves in it's own right in the absence of iron.

For most intents and purposes it is the same except for a few small things. You won't have magnets. It doesn't spark so you couldn't have flintlocks. It can't be made as hard as high carbon steel but high carbon steel that wasn't brittle was very hard to make and usually reserved for high-quality swords. Pretty much everything made of iron that a regular person used could be replaced with bronze if it was cheap and plentiful enough. The problem is that it stops being cheap and plentiful enough by TL2. There isn't enough of it to replace iron.

[Sindri]

Originally Posted by DanHoward

There aren't any noticable improvements in mining technology from the Roman period until the Industrial Revolution. There were advancements in smelting technology - you'd probably be able to recover 10-20% more metal from ore using late TL4 smelters compared to earlier ones.

Good to know.

Originally Posted by DanHoward

For most intents and purposes it is the same except for a few small things. You won't have magnets. It doesn't spark so you couldn't have flintlocks. It can't be made as hard as high carbon steel but high carbon steel that wasn't brittle was very hard to make and usually reserved for high-quality swords. Pretty much everything made of iron that a regular person used could be replaced with bronze if it was cheap and plentiful enough. The problem is that it stops being cheap and plentiful enough by TL2. There isn't enough of it to replace iron.

Well how it behaves includes the cost. Does anyone know the best alternative for sparking though? That seems interesting.

[whswhs]

Originally Posted by Sindri

Sure, I'll definately take these numbers for a spin and see what they behave like. Does your bronze age world have a name that I can look for to read relevant threads? I'm currently on the catching up phase of my reading all the gurps threads status.

The campaign is called Tapestry and the world is Tela. There were some extensive threads about it on this board a few months back. You can also find discussion at whswhs.livejournal.com.

Bill Stoddard

[whswhs]

Originally Posted by Bruno

Native iron (and meteoric iron) introduces you to the idea of iron. But if you're mining copper, you've probably figured out copper ore and the idea of "fancy coloured rocks what got metal in them" is a well known thing. After THAT, with that bit of trivia floating around, inevitably someone is going to wonder about ores of iron.

The big problem is that the temperature needed to smelt iron seems to be higher than that needed to melt copper. So you need progress in the art of the furnace.

Bill Stoddard

[Culture20]

Originally Posted by Sindri

Does anyone know the best alternative for sparking though? That seems interesting.

Titanium makes great sparks. Of course so does wood, and wood is more plentiful.

[Anthony]

Originally Posted by Sindri

Well how it behaves includes the cost. Does anyone know the best alternative for sparking though? That seems interesting.

There should be other rocks that spark, but the examples I found were talking about iron pyrite.

As a side note, I suspect any world iron-poor enough for this to be a problem is also iron-poor enough for iron-deficiency anemia to kill people.

[whswhs]

Originally Posted by Anthony

There should be other rocks that spark, but the examples I found were talking about iron pyrite.

As a side note, I suspect any world iron-poor enough for this to be a problem is also iron-poor enough for iron-deficiency anemia to kill people.

Or for the sapient race to use a different respiratory pigment, such as one based on copper.

Bill Stoddard

[malloyd]

Originally Posted by DanHoward

My initial point is that there would be no TL4 society on Earth without iron. You can't simply replace iron with bronze. There isn't enough accessable tin and copper on the planet.

That's always a tough thing to demonstrate, because of the way known reserves tend to depend on how profitable it might be to look for them, and because the ambiguity of "accessible" vs "economic".

Current tin production is about 250 kilotons per year. That's plenty to make a megaton of bronze (and with 19.2 megatons of copper produced last year tin is clearly the limiting reagent). That exceeds the world's iron production until sometime around 1810, so there was enough metal on the planet, and accessible without superscience even since we aren't using any, to completely replace iron with bronze at TL4. The hard to answer question is how much more it would cost to extract that much, particularly with TL4 rather than TL8 methods. Almost certainly too much to be anywhere close to economic, but that's not quite the same thing.

[Sindri]

Originally Posted by whswhs

The campaign is called Tapestry and the world is Tela. There were some extensive threads about it on this board a few months back. You can also find discussion at whswhs.livejournal.com.

Bill Stoddard

Ahh I remember reading some interesting threads on Tapestry (it somehow slipped my mind that it was a bronze age world), but I probably missed some stuff so I'll make sure track them down ahead of schedule.

Originally Posted by Culture20

Titanium makes great sparks. Of course so does wood, and wood is more plentiful.

Indeed, although a matchlock is probably a better choice than a "woodlock".

Originally Posted by Anthony

There should be other rocks that spark, but the examples I found were talking about iron pyrite.

As a side note, I suspect any world iron-poor enough for this to be a problem is also iron-poor enough for iron-deficiency anemia to kill people.

Quite true, I'm going to cheat with magic on that score though...

Originally Posted by whswhs

Or for the sapient race to use a different respiratory pigment, such as one based on copper.

Bill Stoddard

Was a close contender and might make a partial appearance yet.

Originally Posted by malloyd

That's always a tough thing to demonstrate, because of the way known reserves tend to depend on how profitable it might be to look for them, and because the ambiguity of "accessible" vs "economic".

Current tin production is about 250 kilotons per year. That's plenty to make a megaton of bronze (and with 19.2 megatons of copper produced last year tin is clearly the limiting reagent). That exceeds the world's iron production until sometime around 1810, so there was enough metal on the planet, and accessible without superscience even since we aren't using any, to completely replace iron with bronze at TL4. The hard to answer question is how much more it would cost to extract that much, particularly with TL4 rather than TL8 methods. Almost certainly too much to be anywhere close to economic, but that's not quite the same thing.

This fits with my intuitive understanding of metal reserves better than the same volume as historical bronze age. I of course don't have any real expertise in the area though, hence the thread and it seems possible that a good chunk of modern tin production is just infeasible at TL4. I would expect some degree of increased mining as the economics shifts due to changes in demand.