Yesterday's Tommorow: A Plausible Roman Steam TL

[Flubber]

Originally Posted by DonMegel

Correct me if I am wrong but the general consensus is my TL can not happen the way I am laying it out...

That's my position and I believe it to be Elfwine's position too. I can't speak for anyone else.

... because a high pressure (20-30psi) steam engine could not have been developed within 15-20 years giving the technology of the time.

Twenty to thirty PSI isn't high pressure.

...

Jacob Leupold created a high pressure engine in 1720...

No. Leupold wrote down the design for one in a book. He never actually built the design. Leupold was also one of the premier instrument makers of his day, a specialist in pumps, and had both reports and working models of steam engines to examine. Heron/Palonius have non of those things.

James Watt made a huge advance in steam design in less than 20 years.

Watt had the incalculable benefit of improving on preexisting designs and tinkering with already working examples. Again, Heron & Co. do not have that advantage.

Ofcourse this was a low pressure engine where as mine are high pressure.

The designs in question are not "high" pressure ones. Your lack of research and comprehension is showing again because you are unaware of the differences between an atmospheric engine and a true steam engine.

All early steam engines actually used air pressure to move the piston. Steam first heated the cylinder that housed the piston. The cylinder was then cooled creating a vacuum. The difference in pressure between that vacuum and the atmosphere then moved the piston within the cylinder. Watt's advance was to introduce a separate condenser so that the piston cylinder needn't be repeatedly heated and cooled thus saving lots of fuel. (Watt also later introduced the technique of injecting steam in the top of the cylinder to assist atmospheric pressure in moving the piston. The atmosphere still did a majority of the work however.)

With descriptions and working examples of atmospheric engines in front of him and with his life long experience in making scientific instruments of all types, Leupold designed but did not build an engine which used steam and not the atmosphere as it's motive force.

Why does hot water make the Aeophile spin? They had no clue, but it did, and from that premise an engine like Jacob’s could have been developed.

Seeing as the Aeophile doesn't use pistons, it isn't much help in developing a piston engine.

I wanted to be an Aeronautical engineer until I started getting into more advanced math...

You don't need advanced math to understand steam engines.

... do not take this as an insult to any engineers but, the advantage of my not having a background in engineering is I don’t have to think like one.

Please do not take this as an insult either, but the fact that you don't understand how something works means you have no ability to speculate about how it could work differently.

I get to look at these issues like Heron would, with no idea how it is going to work out.

Heron had no idea about how to build a useable steam engine in the OTL and guess what? He didn't build a useable steam engine.

They would not know that the leaf spring would eventually compress and lose its spring, making the gauge less accurate. For this reason I am grateful that you are pointing out flaws in my designs so that I can wrap the story around that, but I cannot see the impossibility.

Google leaf spring, go to the Wiki page, and look at the very first picture of their use in the suspension of a Jeep. Then tell us how that type of device is working inside our piston pressure gauge.

As for calibrating my gauge, I almost wrote about how Braxis did that but did not want to get too far down into the weeds.

You're in the weeds already, sadly.

Braxis knows, from experience, about how much pressure his boiler can take.

How? Seriously, how? The only way he can measure is to destroy the boiler in question and, when that boiler is rebuilt or repaired, it's pressure keeping capabilities will have changed. Boiler A is going to rupture at Pressure B, but Repaired Boiler A will rupture at a different pressure as will Boiler C. Without being able to measure, Heron can blow up every boiler he makes and still not learn a thing.

He heats the boiler to that point...

How? Again, seriously how? He has no way of measuring temperature. He can't even use the ancient smithing color technique. How does he know he's heated Boiler A during Test 2 to the same point as he did in Test 1?

I also almost described the safety valve but skipped it for the same reason. A hole in the boiler is filled or covered with a weaker material that would fail before the pressure would become great enough to destroy the entire boiler.

That's a rupture disc and they're used today. Valves are better for several reasons and valves are easier to construct.

How would Braxis know? Trial and error using his gauge.

Because Braxis cannot repeat his experiments in an real sense, and that's because he cannot measure the pressure and heat involved, trial and error in his case will produce nothing but error.

I really did not want to get this in depth about steam power with my TL, its supposed to be about how steam power cold have altered Rome, not debating the fine points of the technology.

These are not fine points. These are basic facts which must be acknowledged and addressed if your time line is to have an credibility. Being aware that steam engines operate in a certain manner and that manner requires certain physical laws is like being aware that Romans weren't named Moe, Larry, and Curly.

My POD is Heron created a “high pressure” steam engine using pistons.

That's not a POD. That's an ASB intervention; i.e. Skippy the Space Bat shows Heron how to build a steam engine so what happens next?

You're obviously intelligent, so you can learn what you need to know.

Good luck.

[Elfwine]

Originally Posted by Flubber

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That's my position and I believe it to be Elfwine's position too. I can't speak for anyone else.

Yeah, the way this is being laid out does not work at all.

[DonMegel]

I only put “plausible” in the title so that people wouldn’t think this was a steam punk TL. I didn’t think it would mean I had to produce archeological evidence of a Roman steam locomotive in order to escape scorn. If I could remove it I would.

Originally Posted by Flubber

You're obviously intelligent, so you can learn what you need to know.

Again, thank you, but what good is more knowledge about steam engines if your position is that my POD, a useful Heron engine, is impossible? That is the entire basis for my TL.

81AD- The new year dawned and passed quietly in Alexandria, save the typical celebrations inherent to that time and location. In years past, Polonius was quick to take part in the festivities but, so recent was his chastisement, chose to remain on campus instead. Not four months passed before another representative of Titus arrived to inspect the pair’s progress. As before, there was not much to show. Braxis had tried dozens of different boiler arrangements trying to get the most pressure from the smallest package while Polonius had been experimenting with different piston and level combinations but neither men had a workable solution to show Titus.

After the slave departed for Rome, Polonius began to fear his boasting would cost both of them their lives but this fear was short lived. In September, word reached Egypt that Emperor Titus had succumb to fever and died, succeeded by his brother Domitian. Polonius, who traveled with the Emperor and knew him to be in good health and sound mind, was both shocked and relived. The Emperor’s demands for results were no longer as threatening, due in large part to him being dead, but this also meant the elaborate public works projects and military contracts he offered were also gone, to say nothing of Imperial patronage.

For others, the Emperor’s death had a more sinister meaning. Pliny the Elder, who dedicated one of his elaborate books to Vespasian’s son, immediately suspected Domitian was more than a helpless bystander when Titus grew ill. Rumors that the new Emperor packed his brother in snow to “freeze” the fever out of him did not help to ease Pliny’s mind and he soon began asking more probing questions.

To Domitian’s credit, he did not have Pliny executed as Emperors past would have done, perhaps out of fear of public opinion but, as he later abolished the practice all together, more likely due to personal convictions. In any case, Domitian grew weary of Pliny’s inquiries and resigned him to Gnaeus Julius Agricola’s forces in Brittian, litterally removing him from the mainland of Europe.

[Flubber]

Originally Posted by DonMegel

Again, thank you, but what good is more knowledge about steam engines if your position is that my POD, a useful Heron engine, is impossible?

That is not my position at all.

My position is that a useful Heron engine developed in the manner you have described is impossible.

That is the entire basis for my TL.

Then your time line belongs in a forum with different standards for plausibility. Not worse standards or lower standards, but different standards.

[DonMegel]

I have started a new thread, partially rebooting my TL

http://www.alternatehistory.com/disc...d.php?t=252104

[Hyperion]

Originally Posted by DonMegel

I only put “plausible” in the title so that people wouldn’t think this was a steam punk TL. I didn’t think it would mean I had to produce archeological evidence of a Roman steam locomotive in order to escape scorn. If I could remove it I would.

Whether or not the world plausible appears in the timeline title has nothing to do with the quality of the timeline in general.

While the idea is in and of itself interesting and something I've seen others look at before, your basically having someone in about 20 some odd years do what in OTL it took dozens of people over 100 years to accomplish with far better understanding of science and technology involved, far more resources, and far better transportation and communications and a better industrial base.

Now if you spaced this out to about 100-200 years or so, a lot more trial and error, and more earlier setbacks, I could see this being much more practical.