Steel was already being used in Europe 2,900 years ago, shows study | Hacker News Reader

Steel was already being used in Europe 2,900 years ago, shows study

phys.org

129 pointspseudolus67 comments

I suspect steel making was one of those pieces of knowledge that got lost frequently. The reason: it's incredibly expensive, in terms of energy requirements.

I have read that Roman legionaries, covered in armor, took acres of wood per soldier to make the charcoal needed to make the steel using traditional methods. Entire regions could be deforestated to outfit an army.

Technology is the story of better access to energy and information over time. Steelmaking requires both, and 2900 years ago we had very poor access.

Edit: as Luc pointed out below me, that figure is just for iron armor. Proper steel requires higher heat and even more energy.

"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-...

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?

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.

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.

Iron cookware, as opposed to cast iron cookware, is not "basically impossible to get," is composed of iron and contains no alloys.

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.

> 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.

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.

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.

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

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.

An excellent point. I wonder how it compares with the material and labour resources involved in equipping a modern army.

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

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...

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.

I’m no expert, but it’s my understanding that modern war uses huge amounts of ammunition for suppressive fire.

This is true, but there are a lot more hours available now than then. Global supply chains mean a modern "legion" can draw from the labor of 8 billion people. Those workers live longer lives, and far far fewer of them are working in agriculture just to keep themselves fed. This is before factoring in their productivity -- an hour of 2023 globalized labor is presumably many times more productive than an hour of 500 BCE Roman labor.

Throw in the resources needed for ships, civilian and military, civil infrastructure and the like, and you see why there is so little forest left in the Mediterranean. Plus, those things have to be replenished and rebuild over time, so it is not a one off.

I think the main reason there is that those areas have been inhabited for so long, and that wood is mostly used for cooking and heating, uses which would eclipse military production. And don't forget clearing forests to make fields for agriculture.

The heating needs are usually regrowing. Agriculture is a thing, sure. The majority of the forests on the Italian peninsula was used up by the powera to be, from the Romans to the Venetians, was used for ships now lying somewhere on the sea floor. You can read up on the history of the Battle of Lepanto, the Venetian Arsenal and just how much wood was cut down for that fleet on the Venetian side not to speak of the Ottomans.

Having the logistics in place for these kind of things is among the main reasons the Roman were able to buiod their empire in the first place.

It's a lot for a preindustrial society that has a very low surplus economic output that can be collected and diverted into a military by taxes.

Also, the logistics of keeping the legion fed and quartered when it is resting, or campaigning look a lot like 'it eats the countryside bare, and the peasants unlucky enough to be in its path starve'.

Even in an industrialized society, how many families do you know that would be able to quarter and feed, say, three to six soldiers for the four months break that they take from winter campaigning?

The real problem is that the Mediterranean islands had forests,

Forests that evolved in a similar way to the outstanding current Asian temperate forests that are a hot spot of temperate biodiversity. They were the home to endemic conifers, "italojapanese" maples, dwarf European elephants and rodents like bunnies with teddy bear ears.

All gone now. We will never know how an European "Asian jungle" would look.

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.

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.

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

> 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.

> Technology is the story of better access to energy and information over time.

This is an under-appreciated fact of history. Wealth and prosperity closely track the availability of cheap energy, which is why interfering with energy production in the name of supposedly higher goals is such a high-stakes gamble.

"We’ve gone from spending 4% of GDP on energy to spending 14% - a 10% loss straight away to just keeping the lights on, money that could be spent doing other things we care about, including energy." [0]

[0] https://climatepodnotes.substack.com/p/its-energy-stupid

A related fact is that sometimes “advanced technology” really just means using more energy. A simple tech example is the escalating thermal budgets of CPUs. Yes, if you let them draw more power, they can run faster. In my view, that’s a less interesting technological development than an innovation that allows more work to be done with less energy, or that unlocks previously inaccessible energy. Those are the type of inventions that truly qualify as an advancement.

> A related fact is that sometimes “advanced technology” really just means using more energy.

I don't think this is what generally happens. Chips right now do this because Dennard Scaling / Moores Law are coming to an end, so they have to increase performance in different ways to win some dumb benchmarks. Nearly everywhere else its the opposite. Cars, fridges, heating, houses, lighting - they all use less energy than they used to.

Jancovici's conference about how ecology and economy eventually boil down to fundamentals such as energy is eye opening:

https://www.youtube.com/watch?v=KtQBPhKSWu0&list=PLMDQXkItOZ...

The punchlines are wonderful. E.G: "The first law of thermodynamics will always win over political promises".

Highly recommended.

Some of his conferences and courses (in particular the École des Mines 20h course) are available with English subtitles.

Do you have a link?

Here you go:

Dubbed videos (mostly English but also Russian and maybe other languages): https://www.youtube.com/playlist?list=PLMDQXkItOZ4JcKrdHyRaA...

Videos with English subtitles: https://www.youtube.com/playlist?list=PLMDQXkItOZ4II_sYvh0Be...

Thanks.

The first one is French dubbed in russian. If you speak russian, I would recommend it as it as the slides clearly in view.

However, the second one, in English doesn't show most of the slides, and they are really necessary to get the full picture. However, it's a playlist, and there are better ones in there.

If you don't mind, I will update my comment to include one of them.

> Technology is the story of better access to energy and information over time. Steelmaking requires both, and 2900 years ago we had very poor access.

Yes - and the modern industrial revolution involved a particular kind of "takeoff", as the iron and steel could be used to make steam engines which made mine pumping and ventilation easier, enabling more coal to be extracted to make more iron. Likewise in the modern era advances in oil drilling. It's all EROEI (energy return on energy invested).

The natural resources renew at a comparatively limited rate. Before cheap coal, Scotland was denuded of trees; WW1 also caused a historical low point in European forest cover.

This is why the transition away from fossil fuels before access to them starts getting too much more difficult is so important.

The process to make iron also resulted in a small amount of steel. You would have to outfit a couple legions in armor just to get enough steel for one sword, and then you have to collect that iron which might not have already been done. Thus the legendary swords that could cut armor like it was butter: if you collected all that steel your could make such a sword, but not many.

I remember NOVA did an episode "Secrets of the Viking Sword" (a sort of sequel to a similar episode about Japanese sword making traditions) where a modern blacksmith created a sword using presumed methods from the viking era to create a crucible steel sword. They pointed out the advantages that the better metallurgy would provide; I remember them showing the sword flex while most contemporary swords would have broken.

The idea was that this was sort of a trade secret for steel production and so it was rare and this may be one of the sources for legends of "magic swords".

No doubt it took a great deal of wood; this is also one of the reasons Pennsylvania in America developed a metallurgical industry. Plentiful wood for charcoal (this was before they started using coal, which Pennsylvania also had in abundance)

However I just want to point out that an acre really isn't that big. A single typical Roman fortification could easily cover tens of acres just inside the walls. "acres of wood" isn't really saying much.

Wow, thanks for visualizing this so vividly. I've never thought about it, but this is probably one more reason why Europe is as deforested as it is.

When archaeologists say it "isn't possible to do X with Y", having attempted to do it in an afternoon of trying, I don't really believe them...

2,900 years ago there were lots of people, each with lots of time. It seems very possible that there was some way to carve this stone, and we just haven't discovered it...

For example, maybe the stone is weakened if you try to carve it after a frosty night... Or is weakened by being soaked in lemon juice... Or is just worn away by being rubbed against another piece of the same stone...

There are all kinds of methods of achieving the apparently impossible which are non-obvious.

They did also find the actual chisel, though. And it's very possible that, say, rubbing acid or scraping with a stone does make a mark, but I bet it's sufficiently distinct in shape, side effects, etc to be ruled out here.

> archaeologists say it "isn't possible to do X with Y"

Do they?

Many people use "everyone said X was impossible, but I found out how to do X!" as a framing device to tell their story, but whenever I investigate one of these I generally find that it isn't strictly, err, true. People weren't saying "X is impossible" so much as "we think tribe T didn't know how to do X so this artifact was probably imported" or something similarly hedged. The new information is genuine, but the narrative is just storytelling.

> there were lots of people, each with lots of time

I bet tons of Human innovation came from people just having time and nothing to do. I wonder, throughout history, if this was a privilege or if even ordinary people had time like this (obviously not the resources necessarily).

I suspect that throughout history there has generally been quite a lot of 'free time'. Music and art and drinking alcohol all appear to be mostly free time/entertainment things, and I suspect a group of people who had to work for all of their waking hours wouldn't partake in those things much.

Even in nature, it seems most creatures have a lot of free time. For example, most birds seem to spend much of their time sitting in trees chirping, rather than hunting for worms/seeds. I could imagine that "I have free time to sing" is a big sexual selector - an individual who doesn't need to spend 24/7 hunting for food is a 'stronger' mate. I wonder if the same applies to humans?

Alcoholic beverages were used for a long time as a more sanitary alternative to water not as an amusement.

"The future is already here — it's just not very evenly distributed."

"Forging a Katana"[1] is a fantastic documentary! I learned to appreciate steel as a material and what it takes to create a steel blade. There is so much craft and experience required to make one. Here's[2] another documentary about making of Santoku knife.

[1] https://www.youtube.com/watch?v=VE_4zHNcieM

[2] https://www.youtube.com/watch?v=tbbky_RwFyc

I saw that as a NOVA documentary[0]. They also had a sequel of sorts, "Secrets of the Viking Sword" that showed a modern blacksmith trying to re-create crucible steel from that era[1].

[0]https://www.pbs.org/wgbh/nova/ancient/secrets-samurai-sword.... [1]https://www.imdb.com/title/tt2204408/

That is such a rabbit hole! A book I can recommend is "The Art of the Japanese Sword" by Leon and Hiroku Kapp. Also a great resource if you want to go into knife / blade making yourself.

What is really interesting so, is the metallurgy behind that. Basically, Japanese blacksmith had to work around the fact that all they had was basically crappy ore deposits with loads of unwanted impurities. And they did so masterfully.

Modern day mono-steel is ahead of whatever historical swordsmiths had, it is almost ridiculous. One of the greatest benefits, besides having clearly defined and refined properties regardless of batch, is how easy heat treatment is. Those standardized properties mean what ever part one makes behaves the same way when heat treated at a certain temperature. And that temperature is surprisingly easy to control, guessing the right temperature was what kind of made sword making a black art so to say.

EDIT: Also look up Peter Johnsson, he has great content on the geometry and dimensions of European swords. His swords, from Viking style all the way to renaissance ear ones, are pieces of art. He is also really accessible, I just shot him a mail with questions regarding heat treatment of blades for a yet to start project, and the back and forth was really, really helpful.

Primitive Technology: Decarburization of iron and forging experiments:

https://www.youtube.com/watch?v=pOj4L9yp7Mc&t=7s

There’s a big difference between possible and practical. There’s a reason steel production didn’t take off until the Industrial Revolution.

wtf this fact melts my brain! Man already knew (meteoritic) steel and it is a known fact, but that we could already produce it is absolutely mind f-ck and rewriting the history books, predating by millennia some dynamics that were previously certain

That seems histrionic...what rewrites or dynamics are going to be significantly changed? I mean, it's a fascinating discovery and all and thank gawd our ancestors were so clever. A timeline or two might get updated, but the headline seems to be "culture that left little evidence of their existence figured out how to make steel to make marks on hard rocks; no one else picked up on it for a millennia or two". This isn't by any means the first time we've found some ancient culture figured out something really neat earlier than we expected but it didn't go anywhere at the time.

producing steel requires a huge, huge amount of knowledge, energy (fire) and materials (wood, coal and ores), it took us millennia to maximise the process... to know that someone, even 'accidentally', was producing it eleven centuries earlier is at least fascinating to me;

Actually, I don't know how 'revolutionary' it is in total, but in the meantime my brain explodes!

I think you're generally dating steel production too late (100AD?) As mentioned in another comment, earliest known was nearly 4000 years ago, and there was quite large-scale production in India by about 2500 years ago. Steel didn't really take over the world until later (arguably not _really_ until the Industrial Revolution), but that was more down to the practicalities of making it than anything else.

linearity in history will be seen in our future like newtonian phisics, good enough to describe what we see but "incomplete", the "relativity equivalent" would be outburst of (relatively isolated) civilizations that collapsed without leaving substantial legacy. For example known unknown great ancient civilizations as Bactria–Margiana Archaeological Complex (Oxus) or guatemala cities under rainforest

Newtonian physics is still good enough and used every single day. "Civilizations that collapsed without leaving substantial legacy" are footnotes in academic papers: fascinating and useful if you're in the tiny number of people in the field of research, not so much otherwise. Not the same thing at all.

I mean, while this is certainly interesting, it's worth noting that this is just pushing back the date for steel production _in Europe_. The earliest known steel production is quite a lot earlier (1800BC), but it was in what's now Turkey.

I guess any steel from that long ago is bound to have vanished by now, they surmised that only a steel chisel could have made the carvings. Is there anything else which could also be hard enough to carve the rock? A chisel made of rock?

Their geochemicalanalysis, metallographic analses, and experiments showed it wasn't possible with iron, required a carbon content high enough to call 'proper steel', and your suggestion is hey maybe they used a rock?

Both steel and quartz have a mohs hardness of about 7.... just sayin'

Steel in the right conditions can last almost forever. Lacking water or lacking oxygen are the main preservers, and there are plenty of pockets underground with those conditions.

If there were any substantial number of steel tools 2,900 years ago, we would have found one by now.

However, if there were just a few very rare examples, it's unlikley we'd find evidence of them.

Steel is a byproduct of iron production in very small quantities. If you separate that steel out you can make a knife, but it is a once in a lifetime for iron production regions. So it could be that rare examples is all we get.

Though who knows if a better process was found and then lost.

They found a steel chisel and also tried to work the rock with softer chisels, and couldn't.

"Analysis of an iron chisel found in Rocha do Vigio showed that Iberian stonemasons from the Final Bronze Age had the necessary tools. The researchers discovered that it consisted of heterogeneous yet astonishingly carbon-rich steel. To confirm their findings, the researchers also carried out an experiment involving a professional stonemason, a blacksmith and a bronze caster, and attempted to work the rock that the pillars were made of using chisels of different materials. The stonemason could not work the stone with either the stone or the bronze chisels, or even using an iron chisel with an untempered point."

They found a steel chisel from the time period, "This was backed up by metallographic analyses of an iron chisel from the same period and region (Rocha do Vigio, Portugal, ca. 900 BCE) that showed the necessary carbon content to be proper steel."

Gives a new meaning to "Toledo Steel."

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