7 ms·

"To put that in some perspective, a Roman legion (roughly 5,000 men) in the Late Republic might have carried into battle around 44,000kg (c. 48.5 tons) of iron

by Luc 4y ago

"To put that in some perspective, a Roman legion (roughly 5,000 men) in the Late Republic might have carried into battle around 44,000kg (c. 48.5 tons) of iron – not counting pots, fittings, picks, shovels and other tools we know they used. That iron equipment in turn might represent the mining of around 541,200kg (c. 600 tons) of ore, smelted with 642,400kg (c. 710 tons) of charcoal, made from 4,620,000kg (c. 5,100 tons) of wood. Cutting the wood and making the charcoal alone, from our figures above, might represent something like (I am assuming our charcoal-burners are working in teams) 80,000 man-days of labor. For one legion." Of course it's from https://acoup.blog/2020/09/25/collections-iron-how-did-they-make-it-part-ii-trees-for-blooms/ https://acoup.blog/2020/09/25/collections-iron-how-did-they-...

mabbo 4y ago
That's where I read that! I had forgotten, but of course it was the delightful Bret Devereux. Still, that was just for iron. Steel requires even more energy- higher heat I believe?
- hef19898 4y ago
  And better ore. And more of it. It was until the early 20th century, way into the industrial revolution, that iron production outpaced steel production by 9 to 1. Today it is the opposite, with simple iron basically impossible to get.
  - cwillu 4y ago
    As I understand it, what we call “mild steel” is simple iron; there is practically no carbon in it. The difference with what we have today is mostly the lack of other impurities: no slag distributed throughout the metal, and no sulfur dissolved in it.
  - Maursault 4y ago
    Iron cookware, as opposed to cast iron cookware, is not "basically impossible to get," is composed of iron and contains no alloys.
    - hef19898 4y ago
      What we call cast iron today is also basically just low grade steel. Pure iron, as used 100+ years ago is simply not made anymore. Also, most of the steel used nowadays is recycled, one way or the other.
      - Maursault 4y ago
        > Iron cookware, as opposed to cast iron cookware Did you not see that? Cast iron cookware is not iron cookware. Iron cookware is still available, generally labeled "pure iron" and marketed to impart more iron into the food being cooked than cast iron cookware. Maybe your waving hand should take a rest.
- Tuna-Fish 4y ago
  It's not just about heat. Steel is an alloy of iron and carbon. The traditional way to infuse carbon into the metal was to place wrought iron ingots (that is, ones with almost no carbon, too soft for use) into a charcoal fire that was being starved of oxygen, for days. You had to regularly add more charcoal, which both provided the necessary heat and slowly seeped into the metal. As mobility of carbon is very low at low heat, most of the charcoal is wasted as fuel. Around the same time, the Chinese had already figured out the much more efficient process of starting with cast iron (iron saturated with carbon, easy to make but too brittle to use), and heating and working it in a very oxygenated environment, burning out the excess carbon.
lqet 4y ago
I strongly suspect this is why half-timbered houses, although being much more earthquake resilient than stone houses, haven't been common in Italy for thousands of years now. There simply wasn't enough wood left.
- febusravenga 4y ago
  And almost no old castles, palaces or significant ruins in flat and rock-less areas like west pomeranian in Poland. Bricks and stones were so valuable, that any abandoned stone/brick building was dismantled immediately for material for new buildings.
canadianfella 4y ago
[dead]
the_mitsuhiko 4y ago
I think the Linz-Donawitz steelmaking process does not get enough credit sometimes for how much it changed steelmaking > It reduced capital cost of the plants and smelting time, and increased labor productivity. Between 1920 and 2000, labor requirements in the industry decreased by a factor of 1,000, from more than three man-hours per metric ton to just 0.003.
boredumb 4y ago
If only they had implemented a small carbon tax to offset this.
twic 4y ago
So sixteen man-days of labour per legionary. And 924 kg of wood; if you get 30 tonnes of wood per hectare (this is a SWAG based on a quick google), that's about 300 square metres per legionary. For 5000 legionaries, that's 154 hectares, which is about a quarter of the Presidio in San Fransisco, half of Central Park in New York, or a bit more than Hyde Park in London. It's a lot, but it doesn't strike me as, like, a lot a lot.
- notahacker 4y ago
  An excellent point. I wonder how it compares with the material and labour resources involved in equipping a modern army.
  - tokai 4y ago
    I wouldn't be surprised if the man hours per equipped soldier its much higher in a modern army. If you account for all the individual bits and bops, plus vehicles and modern weapon systems. That would follow the trend from the last +100 years where the price tag for the individual soldier sky rocketed.[0] [0]https://www.nbcnews.com/id/wbna21105586 https://www.nbcnews.com/id/wbna21105586
    - notahacker 4y ago
      The other interesting angle is if you measure it per population unit defended, on the basis the point of all the heavy equipment is the ability to win wars without having to call up a particularly large fraction of the population to fight in them (the Romans are also outliers in history for ruling a large population with a relatively small skilled standing army rather than mass conscription) But still not convinced that comes out at lower cost than the Romans. Lucky we've got a bit more productive capacity not devoted to producing food and basic infrastructure than they did...
      - jabl 4y ago
        IIRC there's a long series on the acoup blog referenced elsewhere in this discussion, that deals with the logistics of moving and feeding an army in pre-modern times. Tl;dr: When you're limited to beasts and wagons, the possible size of your army is severely curtailed. Also foraging for food (again, with beasts and wagons there's only so much food you can transport over any non trivial distance) puts a quite low limit on the size of an army you can have in an area. IOW, the modern mass army enabled by conscription is also dependent on a modern logistics system to supply them.
deleted 4y ago
[deleted]
hammock 4y ago
Only half of a legion was deployed in battlefields at any given time. So call it eight man-days per legionnnaire to outfit a legion, which is nothing in the era of slavery. Add to this that the equipment would be expected to last the 20 years that Roman served in the legion, and it looks pretty good
Maursault 4y ago
> might have carried into battle around 44,000kg (c. 48.5 tons) of iron I suspect there were no Roman legions exactly fully equipped. Swords and weapons were probably far more popular than armor. And it's not like they discarded this stuff; it would be collected and redistributed possibly for generations.

by Luc 4y ago

mabbo 4y ago

That's where I read that! I had forgotten, but of course it was the delightful Bret Devereux. Still, that was just for iron. Steel requires even more energy- higher heat I believe?

hef19898 4y ago
And better ore. And more of it. It was until the early 20th century, way into the industrial revolution, that iron production outpaced steel production by 9 to 1. Today it is the opposite, with simple iron basically impossible to get.
- cwillu 4y ago
  As I understand it, what we call “mild steel” is simple iron; there is practically no carbon in it. The difference with what we have today is mostly the lack of other impurities: no slag distributed throughout the metal, and no sulfur dissolved in it.
- Maursault 4y ago
  Iron cookware, as opposed to cast iron cookware, is not "basically impossible to get," is composed of iron and contains no alloys.
  - hef19898 4y ago
    What we call cast iron today is also basically just low grade steel. Pure iron, as used 100+ years ago is simply not made anymore. Also, most of the steel used nowadays is recycled, one way or the other.
    - Maursault 4y ago
      > Iron cookware, as opposed to cast iron cookware Did you not see that? Cast iron cookware is not iron cookware. Iron cookware is still available, generally labeled "pure iron" and marketed to impart more iron into the food being cooked than cast iron cookware. Maybe your waving hand should take a rest.
Tuna-Fish 4y ago
It's not just about heat. Steel is an alloy of iron and carbon. The traditional way to infuse carbon into the metal was to place wrought iron ingots (that is, ones with almost no carbon, too soft for use) into a charcoal fire that was being starved of oxygen, for days. You had to regularly add more charcoal, which both provided the necessary heat and slowly seeped into the metal. As mobility of carbon is very low at low heat, most of the charcoal is wasted as fuel. Around the same time, the Chinese had already figured out the much more efficient process of starting with cast iron (iron saturated with carbon, easy to make but too brittle to use), and heating and working it in a very oxygenated environment, burning out the excess carbon.

lqet 4y ago

I strongly suspect this is why half-timbered houses, although being much more earthquake resilient than stone houses, haven't been common in Italy for thousands of years now. There simply wasn't enough wood left.

febusravenga 4y ago
And almost no old castles, palaces or significant ruins in flat and rock-less areas like west pomeranian in Poland. Bricks and stones were so valuable, that any abandoned stone/brick building was dismantled immediately for material for new buildings.

canadianfella 4y ago

[dead]

the_mitsuhiko 4y ago

I think the Linz-Donawitz steelmaking process does not get enough credit sometimes for how much it changed steelmaking > It reduced capital cost of the plants and smelting time, and increased labor productivity. Between 1920 and 2000, labor requirements in the industry decreased by a factor of 1,000, from more than three man-hours per metric ton to just 0.003.

boredumb 4y ago

If only they had implemented a small carbon tax to offset this.

twic 4y ago

So sixteen man-days of labour per legionary. And 924 kg of wood; if you get 30 tonnes of wood per hectare (this is a SWAG based on a quick google), that's about 300 square metres per legionary. For 5000 legionaries, that's 154 hectares, which is about a quarter of the Presidio in San Fransisco, half of Central Park in New York, or a bit more than Hyde Park in London. It's a lot, but it doesn't strike me as, like, a lot a lot.

notahacker 4y ago
An excellent point. I wonder how it compares with the material and labour resources involved in equipping a modern army.
- tokai 4y ago
  I wouldn't be surprised if the man hours per equipped soldier its much higher in a modern army. If you account for all the individual bits and bops, plus vehicles and modern weapon systems. That would follow the trend from the last +100 years where the price tag for the individual soldier sky rocketed.[0] [0]https://www.nbcnews.com/id/wbna21105586 https://www.nbcnews.com/id/wbna21105586
  - notahacker 4y ago
    The other interesting angle is if you measure it per population unit defended, on the basis the point of all the heavy equipment is the ability to win wars without having to call up a particularly large fraction of the population to fight in them (the Romans are also outliers in history for ruling a large population with a relatively small skilled standing army rather than mass conscription) But still not convinced that comes out at lower cost than the Romans. Lucky we've got a bit more productive capacity not devoted to producing food and basic infrastructure than they did...
    - jabl 4y ago
      IIRC there's a long series on the acoup blog referenced elsewhere in this discussion, that deals with the logistics of moving and feeding an army in pre-modern times. Tl;dr: When you're limited to beasts and wagons, the possible size of your army is severely curtailed. Also foraging for food (again, with beasts and wagons there's only so much food you can transport over any non trivial distance) puts a quite low limit on the size of an army you can have in an area. IOW, the modern mass army enabled by conscription is also dependent on a modern logistics system to supply them.

deleted 4y ago

[deleted]

hammock 4y ago

Only half of a legion was deployed in battlefields at any given time. So call it eight man-days per legionnnaire to outfit a legion, which is nothing in the era of slavery. Add to this that the equipment would be expected to last the 20 years that Roman served in the legion, and it looks pretty good

Maursault 4y ago

> might have carried into battle around 44,000kg (c. 48.5 tons) of iron I suspect there were no Roman legions exactly fully equipped. Swords and weapons were probably far more popular than armor. And it's not like they discarded this stuff; it would be collected and redistributed possibly for generations.