What is the earliest a practical steam Engine can be built? Practical means that it's not a mere toy, but can be used by public and private organizations as a mean to improve administrative or military efficiency or to produce profit. Hero's aeolipile is a steam engine, but doesn't fulfill the condition of practicability and profitability; Newcomen's atmospheric engine is practical and profitable for pumping waters out of mines, but due to it's flaws, it's use is limited to propel pumps, so I would call it only semi-practical - I don't know if original Newcomen engines were ever used to provide factories with energies. The first really universal engine was Watt's engine, since it really could be use for mulitple and universal applications, like powering mills or steam boats. However, the real breakthrough was the high-pressure engines, since these could be used for all purposes, most notably constructing steam locomotives.

Here some of the important OTL dates:
  • 30-15 BCE: The Roman architect and engineer Vitruvius writes De Architectura, mentionning aeolipylae for the first time, but maybe he copied the works of Ctesibius, probably the first head of the Museum of Alexandria in the 3rd century.
  • 1st century CE: Hero of Alexandria's describes the aeolipile, a primitive jet engine, along with ideas like a vacuum and other means to use thermal energy and steam pressure. However, he considers his sophisticated automats as mere toys, maybe because he recognizes that his machines can't be used effectively for any economic purpose.
  • In the next centuries, again and again stories of aeolipiles and other steam engines are reported from Europe, Turkey and even China - however, these weren't really succesful and none bore fruits.
  • 1630 CE: In a letter, Italian physicist Baliani asks Galileo Galilei why water wasn't rising through a system of syphons 21 metres high. It's possible that Gasparo Berti thereupon built a water barometer between 1640 and 1643 - some sources report the same for Baliani in 1641.
  • 1638 CE: In his Discorsi, Galileo discusses the problem and determine that it's impossible to raise a column of water any higher than 11 metres - this was contradictory to to the Aristotelian concept of the horror vacui, which stated that nature abhors vacuum and thus water would fill any empty place, so that there's no limit to the height to which water can be raised. Galileo tries to explain the problem by stating that the resistenza del vacuo is to weak to achieve more.
  • 1643 CE: Galileo's disciple, Evangelista Torricelli, who took over the problem after his master's death, conducts an experiment to investigate the effect and prove that air has weight - he uses first water, but then at the recommendation of Galileo finds out that mercury is even more effective (about 13.6 times more dense than water at room temperature), so he can uses a tube of 75 cm instead of 10.5 m. The weight that the air exerts on the mercury in a bassin holds up the mercury column, and the space above the liquid was probably the first man-made vacuum, proving the ideos of Hero who believed that a vacuum was possible, but never achieved to create one.
  • 1644 CE: Torricelli announces that the pressure of the atmosphere corresponds to a column of mercury 75 cm in height or a column of water 10.5 m in height. 1 atmosphere is thus equivalent to about 76 cm of mercury.
  • 1648 CE: A barometer is carried to the top of the 1,465-m moountain Puy de Dôme by Florin Perier, brother-in-law of Blaise Pascal. The height of the mercury in it falls by 8.6 cm, which confirmes that the pressure of the atmosphere falls with increasing altitude.
  • 1649 (or 1654) CE: Otto von Guericke invents the first vacuum pump.
  • 1654 CE: Von Guericke demonstrates the force of atmospheric pressure using the experiment of the Magdeburgh hemispheres.
  • 1669 CE: Robert Boyle, in his work Continuation of New Experiments described plans for a truly portable barometer and uses the word "barometer" for the first time already in 1665/6.
  • 1679 CE: Denis Papin, having worked with Robert Boyle since 1676, invents a cooking pot, the steam digester, a high-pressure cooker. He also adds a steam release valve to prevent explosions of the machine, thus creating the first safety valve. This early safety valve consisted of nothing more than a lever and a weight.
  • 1680 CE: The Dutch Christiaan Huygens suggests to use the explosion of gunpowder in a cylinder to create a partial vacuum. The atmospheric pressure would then drive a piston into the cylinder.
  • 1690 CE: Inspired by his works on the steam digester and the idea of his patron Huygens, Denis Papin builds the first piston steam engine. He replaced the exploding gunpowder with cooling steam, with the piston being driven back into the cylinder by atmostheric pressure.
  • 1698 CE: Thomas Savery demonstrates his fire engine called The Miner's Friend for the first time.
  • 1712 CE: Thomas Newcomen installs his first atmospheric engine.
  • 1720 CE: Jacob Leupold designs a high-pressure steam engine which was never built.
  • 1765 CE: James Watt invents the seperate condenser, but can't build an improved steam engine until John Wilkonson invents a precise boring machine in 1776.
  • 1769 CE: John Smeaton start experiments with Newcomen engines and substantially improves them.
  • 1779 CE: A crank added to the Newcomen engine made rotary motion possible. In 1782, Watt creates his own rotative engine using a sun and planet gear.
  • 1781 CE: The first compound engine is patented, which is more effective than Watt's single-acting engine.
  • 1783 CE: Watt builds his first double-acting system and adds a centrifugal governor to it.
  • 1783 CE: The Pyroscaphe, the first paddle steamer, is tested in France.
  • 1799 CE: Richard Trevithik builds the first high-pressure steam engine, followed by Oliver Evans in the US in 1801.
  • 1804 CE: Trevithik builds the first locomotive, propelled by a high-pressure steam engine.
  • 1807 CE: Robert Fulton builds the Clermont, the first viable steamboat.
Well, now I wrote much more than I wanted when I started the thread. According to my source (wikipedia), the discoveries needed for the invention of the steam engine were:
  • The concenpt of vacuum
  • The concept of pressure
  • Techniques for creating a vacuum
  • Means for generating steam
  • The piston and cylinder
Now what do you think - how early could these preconditions be met by human technology? I think that the quality of steal and iron is another important issue, so if you have information of this subject, I would be glad if you would share it with me.

To sum up my question: What's the earliest the steam engine could have been invented?

GWFuckyeah
 
I think the Dutch Golden Age could be a good point. A steam pump makes a lot of sense for the Dutch, it could be a way to improve their land reclamation. MAybe if they had gotten access to the coal fields earlier?
 
It seems to me that the Romans could have invented it, but largely due to the wide availability of slave labor developments like this were not typically pursued by anyone with enough money to do anything with them. After the Roman empire begins to fall however you lose a lot of the stability that would have made it possible to do anything with it and then once they actually fall the knowledge is lost or at least forgotten until much later on, making say the Dutch discovery of it more likely, especially since the use Jurgen brought up is fairly simple while still being tangibly useful.
 
It seems to me that the Romans could have invented it, but largely due to the wide availability of slave labor developments like this were not typically pursued by anyone with enough money to do anything with them.....


Often wondered about this. What were the actual economics of Roman slave labor? There were major mechanical projects that seem to be using water power instead of slave labor. i.e: water powered grinding mills for grain. Cargo ships used skilled sailors & complex sails vs semi skilled oarsmen. Are there other examples we could look at to study the relative costs?

Also note how the use of slaves increased over time. Slave labor vs other labor or economic systems changed between 400 BC & 400 AD
 
One would need a junction of coal, demand for pumping and the ability to cast or fabricate pressure proof boilers, concentric cylinders and pistons within practical limits. China could have managed the fabrication technology and has the coal but not where you would want the pumping. Drainage pumping from depth is a key issue that steam engines can perform that would be difficult with other sources of energy. Animal and human power is expensive. Wind is variable with the winds. Water power could work but tricky to find near somewhere that you want to pump out. Romans later on could have done the task but the starting point with initial inefficient steam engines has to be draining coal mines as they use vast quantities of coal which cannot be transported far. Elsewhere it was suggested that powering canal barges where coal is available to transport on the canals but checking out the arithmetic suggests that a first steam barge would need it's entire load in coal to power it 100km and back so no net cargo.

Our model is England where coal became a mass fuel shipped from coastal sources and increased demand and knowledge of working with iron. Once iron ore and coal were found close to each other the spark was lit. The trick is finding this juxtaposition of fuel and demand with a lucrative market for the end product. The three leading contenders are, in age order, China, Rome and the general Islamic world. Once the genie is out of the bottle we saw general pressure theories turning into a railway system within 200 years.

Now where else could an equivalent model be found in one of these three?
 
It seems to me that the Romans could have invented it, but largely due to the wide availability of slave labor developments like this were not typically pursued by anyone with enough money to do anything with them.

Often wondered about this. What were the actual economics of Roman slave labor?

In fact, the slave labor argument is largely a myth. The slave labor argument roughly goes as follow: "The era of Roman domination saw a time of technological stagnation, since slave labor was cheaper than investments in (new) techniques. As a consequence, the Roman Empire limited itself to spread existing, Greek technology through western Europe, without developing novel means of production." However, this conclusion is flawed due to different reasons, primarily because the Romans did develop and improve technologies, like the water wheel, using it for various purposes ranging from millling over fulling to sawing marble. They used the water wheels combined on a scale one could speak of "factories" since the 1st century, even building special acqueducts to establish mills away from rivers and constructing water turbines.

Two other reasons why you should dismisse the stagnation theory is that the numbers of slaves seems to have declined after the conquests of the republic, and in many places, slave labor was then replaced by quasi-feudal coloni (tenant farmers with a legal status of a serf). Also, in the 60s, German researches showed that in fact slave labor in large manufactories was often related to technical progress and the adoption of new techniques, whereas the real stagnation took place in the little shops of the craftsmen, who were trapped by traditions (and surely hadn't enough money to invest in expensive machines like complex mills or water rights for their industry).

The technological progress in Roman times was certainly slower than today, mainly due to low literacy (which was admittedly higher than in medieval times), to the lack of quick and precise reproductions of books (mainly because the Romans didn't know the printing press), to the absence of fast lines of communications to the scarceness of (public) education and generally to the pre-capitalist stage of economy. But technological progress was a thing in Roman times, surely faster than in previous eras and slower than in later times. So I think that the problem is not an economic, but a technological one. The Romans simply lacked the techniques to produce efficient steam engines and the scientific knowledge (existence of vacuum and atmospheric pressure) to even think of one and to improve existent designs. Which leads me to my question:

and the ability to cast or fabricate pressure proof boilers, concentric cylinders and pistons within practical limits.

What technologies do you need to cast boilers, cylinders and piston? I'm wondering what were the decisive steps between Roman iron age ironworking and modern steel.
 
An early steam engine?

Hmm... China had no small amounts of coal, especially after the 11th century. Could a stronger (and less stupid) Song Empire have developed a practical steam engine, or at least parts of it? There was a significant intellectual culture, and it's not unreasonable to think that several of the discoveries could have been made in China.

That being said, if China had a widely-used steam engine before its introduction by the west, I've never heard of it.

IIRC, @ZhugeLiang had a piece regarding Song Chinese industrialization.
 
[QUOTE="G.Washington_Fuckyeah, post: 14167986, member: 81854"
What technologies do you need to cast boilers, cylinders and piston? I'm wondering what were the decisive steps between Roman iron age ironworking and modern steel.[/QUOTE]

Newcomen built upon cannon casting experience (ie experience in industry generally not personal) to get his cylinders but even then they were flawed with impurities and blow holes and relied upon rope sealing and the low pressure differences of his low pressure inefficient steam system. Watt later was able to use better materials and methods to use high pressure stem which made it efficient enough to spread away from coal mines digging up their own fuel.

Bronze casting would manage the engine side of it and that allows the Chinese to use their early skills in the field and the Romans can industrialise Greek bronze machining. The tricky bit is the boiler supplying the steam. Hence Newcomen using low pressure steam. A high pressure stem boiler is a potential bomb waiting to go off. Hence modern steam engines need no oversight as failures are essentially large leaks but the boilers need formal licencing to ensure that they can contain the high pressures. Watt was able to call upon wrought iron with a consistent predictable quality in sheets that we would call small but to the world then were large. Reducing the number of joints and using new rivet technology combined with new technology of the pressure relief valve. Even so they were lethal monsters for many years. Especially in the hands of ill educated firemen and foremen. The firebox where the heat is made with burning fuel is no problem. Iron, copper and bronze have been used and need only cope with the heat and the heat abstraction by transfer to water keeps that in check. It is where the steam is formed which is problematical. Unless you have all the ducks of Watt lined up just so then high pressure steam would need to use some sort of containment by sheer mass. Look at a stave made cannon. The strength lies in the hoops and uses iron in (relatively) small strips. Within conventional blacksmithing capacity. If you use multiple hoops and surround the whole with some medium then you might just about get away with it but otherwise you are adding nails to the steam pipe bomb by virtue of the matrix. Cannon design gives us some potential possibilities. Wrapping the barrel in rope, leather or silk have been used.

On the whole I see pre OTL steam engines as low pressure devices until material technology catches up. Ironically this points us not just at coal head engines but also very small ones for individual small workshops for specific tasks. Where otherwise you would use a horse mill and free them from water power locations. Even on a self powered cart. Horrible fuel efficiency though and relying more on them being small enough for the fuel to be wood and thus free of coal mining sources. It could alter patterns of city development because sea coal (ie mined near the coast) would be more efficient than wood and workshops would be drawn to cities where coal could be imported by sea (or canal) and there is a ready market. Now you have a demand growing to export the products to the mass countryside market. The leader in the AH economy race would be where you could build canals or possibly flat roads. Voila. An industrial revolution beginning with the steam engine. But, and a big but, low pressure small engines would give a very different result to OTL. Eventually the search for a more fuel efficient engine will lead to high pressure steam and away you go with steam transport etc.

In OTL all that came from commerce. Allowed by government but not driven by them. In China and Rome central government was the source of infrastructure. The state planned and built roads, canals, aqueducts etc. and commerce were merely the contractors and the state would try to use it's military to keep them busy and save money. I can't speak for the Islamic world but I suspect the same. China managed hugely impressive canals IOTL. Barriers to a water transport structure were rapids in the river systems. Could steam engines be backed by the Chinese as a static power source to haul barges up rapids by cable? This would open up a national network and cheapen goods enough to pay for the cost of Imperial steam traction and connect these steam traction stations to a water borne supply of fuel.

A lesser POD would be gunpowder. Again China is my leading contender here. The demands of cannon making are very similar and have to deal with very high pressures. Albeit for moments not hours. Once cannon became established it was not long before large cannon were cast which was a OTL precursor to OTL steam engine manufacturing.

So. I would suggest that a POD would be China at the point where the state could arrange the building of major canals as new cuts and not simply connecting existing waterways. That would be about 500AD. If you begin it with connexions via existing waterways then you just might potentially go back to about 450BC. Now you are looking at an industrialised China with firearms, cannon and maybe steam junks. Welcome to a globalised world run as Chinese tributary states.
 
A lesser POD would be gunpowder. Again China is my leading contender here. The demands of cannon making are very similar and have to deal with very high pressures. Albeit for moments not hours. Once cannon became established it was not long before large cannon were cast which was a OTL precursor to OTL steam engine manufacturing.

Cannon making, that's a good idea. How long should it take for an iron age society ancient China to develop the right iron working to make good cannons?
 
It is no great secret that the Romans did both use slave and mechanical power in their industrial processes - so there is certainly a demand for something like a steam engine - but you aren't looking at the senatorial class, you have to look at those who could be best classed as insurgent actors (i.e. rich enough to try it out, but not rich enough to own an army of slaves), or bleeding hearts/sensible people who don't want slaves dying in mines as much.

I'd probably recommend something around Justinian - because I think so much could be done with an intact Italy it isn't funny - including having the concentrated wealth to fund research like this.

Now, whilst coal is better, you could do a wood steam engine - but I imagine a coal mining industry could rise in Britannia if it was proven to work.

The question is whether the Romans at this point could produce a high enough quality of metal - combine an increased density of wealth, with a Roman Empire that was seen as having a bit of a rebirth, and I think you have the right Zeitgeist in the Empire to lead to weird research like this - especially if it means that the Romans can recruit more people into the army (reduced labour costs, increased economy, yadda yadda).

So if we have a situation that demands the construction of grand new aqueducts that would exceed the 'siphon rule', then we have the incentive to provide a solution - at least based on the OP that led to the invention of the Vacuum Pump, which is great in and of itself. Perhaps I'm missing a step there, but if Justinian wants to show off, he could do worse than build an aqueduct (where is a better question), or something like a water tower to store water for use in the summer to make harvests more reliable.

That at least leads to the vacuum pump, I'm not sure if the conditions to go further and create the steam engine are there, but it could be cool to see a Constantinople where the cisterns are fed by aqueducts and the water then raised into peoples homes via vacuum pumps.
 

missouribob

Banned
Given the small base of knowledge that I have on this subject I'm going to say the Song Empire. They were producing steel, interchangeable parts and seemed to go through a population boom in line with England's agricultural revolution. Really they need a step to push them over the edge to develop a useful steam engine AND survive the societal instability that comes with an Industrial Revolution AND survive as a state against external rivals like the Jin and ATL Mongols.
 
When did tuning bronze bells by 'turning' them come in ? IMHO, the large area of possible 'turned' cylinder suits low pressure steam better than high-pressure cannon tech...
 
Perhaps I'm missing a step there, but if Justinian wants to show off, he could do worse than build an aqueduct (where is a better question), or something like a water tower to store water for use in the summer to make harvests more reliable.

Well, the vacuum pump is only one step towards discovering atmospheric pressure. Once you can measure pressure, you're able to control the pressure in your boiler, at least if you know how much pressure your boiler can stem (and even then, you need precise instruments to control the pressure and good iron to build boilers which are able to bear the measured pressure).
 
Now a little update. I just read the chapter about Steam Power in J. G. Landels' book Engineering in the Ancient World and wanted to share some of the information presented by Landels there. Here what I consider the most important facts on ancient steam power:
  1. Hero's engine wasn't named aeolipile (like Vitruvius' motionless device), but "a ball which soins round on a pivot when a cauldron is boiled".
  2. Hero's rocket engine is impractical for different reasons, among them:
    1. The high speed of the engine. Landels' model of Hero's engine rotated at 1,500 rpm, much to fast for most practical use (like for example pumping or sawing), so you would have needed to gear it down, creating further friction loss.
    2. The transfer of heat from the fire beneath the engine to the cauldron compromises the efficiency.
    3. The greatest problem seems to be the joint between the pipe and the rotating ball. Either you emphasize the tightness which increases friction, or you choose a loose one which increases the loss of steam/pressure. Overall, the engine's energy efficiency calculated by Landel is 1%. A model delivering 0.1 hp (the work of one man) would consume 25,000 B.T.U. or 26.4 MJ per hour. Since charcoal, along with wood the common fuel in ancient times, has a calorific value of about 29 MJ/kg, you would need 0.8 kg per hour to deliver the energy of one man - simply nourishing a slave is much cheaper. To replace a horse you would need 8 kg/h; to replace a Newcomen engine of 5.5 hp 44 kg/h; to fuel a steam locomotive of 2,210 hp 17.68 t/h (OTL: 2.2 t/h); and to fuel a steam locomotive of 6,290 hp 50.32 t/h (OTL: up to 25 t/h). To operate any industry with this kind of engine would be very expensive if you think of the costs to produce the charcoal and transport it to the sites of the industries.
  3. For these (and maybe economic and social) reasons, Hero considered his engine to be only a toy with "quite remarkable effects", whereas he thought that other of his machines provided "useful everyday applications".
  4. Hero's engine is a rocket engine, not a real, useful steam engine. However, his books show that he very much knew of pistons, cylinders and valves, as well as the techniques to manufacture them.
  5. The following question is why Hero never combined boiler, valves, pistons and cylinders to form a steam engine. One answer is that he never thought of reversing the action of a force pump (piston pumpe) by introducing steam into the cylinder to move the piston.
  6. Two other answers are that either Hero died in an explosion while trying to build a steam engine or that he was scared off such a death and therefore never proceeded in this direction.
  7. Finally, another problem might have been the lack of fuel (i. e. coal and coke), since wood is very impractical and charcoal quite expensive. However, charcoal and Roman furnaces were suited to attain temperatures of as much as 1300°C (and even more), even if it's often stated that Roman furnaces were unable to go above 1150°C.
 

PlasmaTorch

Banned
This has been an interesting discussion. The potential of steam engines in the ancient world was brought up on quora a couple of times, and the answers there have alot of good info on the cost to benefits involved, as well as the technological difficultys.

https://www.quora.com/How-would-the...-invented-in-60-AD-had-been-developed-further
"A note about gears: Ancient technology could produce very elaborate handmade gearing which was great for low power clockwork mechanisms, but was awful at efficiently transforming power. That was only made possible by the advent of gear profiles such as the involute gear, which was an invention of Leonhard Euler. While cage gears could, with adequate lubrication, be practical at low speeds, these would not fit the high speed requirements of a de Laval type steam turbine. The ancient steam turbine would have to rely on belt-pulley systems, just like the first steam engines did."

https://www.quora.com/How-would-the...ad-realised-the-full-potential-of-steam-power
"Lastly, the Greeks could not have developed a steam engine because they didn't have the supporting technologies. For example, you need a way to bore straight cylinders in metal; the Europeans learned that by making cannons. You need a way to cast iron in large pieces; that required furnaces much larger than what the Greeks had. And of course the crankshaft for converting linear to rotary motion wasn't known to the Greeks. Lots of other supporting factors such as this played a crucial role as well."
 
And of course the crankshaft for converting linear to rotary motion wasn't known to the Greeks.

The Greeks and Romans were very well able to conver rotary motion to linear one, and the other way around.
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For example, you need a way to bore straight cylinders in metal;

This was probably done by lapping in ancient times.
 
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