Advanced tech without electricity/internal combustion?

Graydon wrote:

pokermind wrote:Steam Engines or Diesel IC engines I can see but, little 1/3 hp engines to run a sewing machine in some lady's home get real there is only so much machine time available and making many low powered engines requiring an open flame no.

Except this actually happened. The concept of a "domestic engine" isn't still with us thanks to electricity, but it was around for a long time. Something that will run the washing machine is a very big deal; washing devours time and effort and we see now a pattern of development where washing machines are the first appliances purchased and make a huge difference to education. (Because Mom now has time and energy to read to kids.) And since powered textile mills on Old Charis are driving the price of clothes down, the need for washing is going up.

About any not dirt poor farm in the late 19th century and early 20th in the USA would have one or two 3 to 5HP hit&miss engine to do such things as elevating grain in the barn, threshing, pumping water, driving machines and more.

Fairbanks-Morse, which was one of the smaller makers, did sell over half a million of its model Z (3 to 20 HP for the late models). John Deere & Amanco probably sold over one or two order of magnitude more than that.

In Europe, it was more a few bigger steam engines owned or rented by the villages but European farms were typically much smaller.

Belial666 wrote:I was considering how Safehold could develop the following technologies without use of the two crucial techs of the 20th century;

1) Automobiles, and by extension armored vehicles.
2) Submarines.
3) Domestic appliances.
4) Airplanes.
....

On domestic appliances:
Growing up, I remember my grandmother's treadle (foot pedal) Singer sewing machine and a manual hand pump washer with wringer attachment. The hassle with the washer was emptying the tub of soapy water and pouring in the rinse water.

Graydon wrote:

pokermind wrote:Stirling engines are low power 1/3 hp is a big Stirling engine.

Because we treat them as toys, mostly; look at the Japanese Sōryū-class submarines, which have four 2,000 HP Stirling Engines in their AIP system. There's nothing inherently small about Stirling engines.

pokermind wrote:Without modern metals ect they weigh more than a steam engine of the same HP. There is a reason they are not in common use they cannot compete with IC engines or electric motors. Less complex than steam? Those modern materials [like Aluminum for the displacer piston] are coming from where?

I'd say the reason is that the IC engines got massive development money for aircraft in the Great War and nothing else caught up. Like turbocompound engines versus gas turbines, it's got something to do with the historical accidents of when and how development happened.

Electric is of course Right Out on Safehold for the foreseeable.

Stirling engines are inherently less complex than steam; closed cycle, so no boiler, no water or fire tubes, no condenser that has to deal with water quality issues, no valves, it's just plain simpler mechanically. They're also quiet, which, in a setting where factories probably occur next to housing (people mostly walk to work!) is a good thing.

The "modern metals" don't need to include aluminium; good steels and copper heat sinks will work fine, Safehold's industry is not yet at a size to make the inherent rarity of copper really problematic.

Also, for a stationary engine, such as is powering a factory, I don't really care how much it weighs, I care how much it costs. A Stirling engine's more efficient than a steam engine; I'm going to pay much less in fuel over the life of the engine. It's inherently mechanically simpler; it will be less expensive to make. If Safehold has a way to get the internal pressure up to 10 bar or so, which does involve sliding seals, this is a really obvious engineering choice because they're starting with 1900-or-so steel technology, rather than 18-low-number steel technology.

For a traction engine, particularly a railroad locomotive, not having to worry about feedwater is a big deal. So is fuel efficiency, because going twice as far on the same coal means I as the railroad operator need half as many coaling stations that don't need to also supply water which means this costs less.

From what it sounds like, a stirling engine might be an efficient one, but it is not one that delivers a lot of HP which a steam engine can do. So there is one strike against it. Another strike seems to be its size. To make a stirling capable of delivering a good amount of HP/DP (dragon power) it sounds like the thing would be -huge-. Too big to be viable for manufacturing factories. Steam engines can be made smaller and given OWLs information database, a lot more efficient for its size. In your opinion, could a stirling deliver the HP needed to run the turbines/flywheel of a good sized factory to power the machines there and be smaller than the building the machines are in?

A stirling locomotive? I can't see that being viable at all. A locomotive/train engine needs a LOT of horsepower in a frame small enough that will still fit on a car to pull the engine and cars behind it. In a steam locomotive, its the team that gives the power to move the wheels to pull the train. I cannot see a stirling engine producing that much power.

Zakharra wrote: From what it sounds like, a stirling engine might be an efficient one, but it is not one that delivers a lot of HP which a steam engine can do. So there is one strike against it. Another strike seems to be its size. To make a stirling capable of delivering a good amount of HP/DP (dragon power) it sounds like the thing would be -huge-. Too big to be viable for manufacturing factories. Steam engines can be made smaller and given OWLs information database, a lot more efficient for its size. In your opinion, could a stirling deliver the HP needed to run the turbines/flywheel of a good sized factory to power the machines there and be smaller than the building the machines are in?

A stirling locomotive? I can't see that being viable at all. A locomotive/train engine needs a LOT of horsepower in a frame small enough that will still fit on a car to pull the engine and cars behind it. In a steam locomotive, its the team that gives the power to move the wheels to pull the train. I cannot see a stirling engine producing that much power.

I think you are a little off, although very large items often contain enough material to make them very expensive. I want to know if a Stirling cycle that could fit on a railcar have enough torque and HP to move a useful payload. Diesel locomotives will be a nonstarter on Safehold untill the proscriptions are overturned unless they go with hydraulic drive, as attempting to drive a locomotive with direct drive would require too many redirects and I do not believe that any clutch material would have a usefull service life.

Zakharra wrote: From what it sounds like, a stirling engine might be an efficient one, but it is not one that delivers a lot of HP which a steam engine can do.

Sōryū-class submarines have four individual 2,000 HP Stirling engines.

Now, aside from noting that submarines are not noted for their expansive and roomy interiors, Kockums -- the Swedish firm whose design those engines are -- has pictures on their website, and it looks like that engine installation, AIP plumbing and all, is a cube roughly 2 metres on a side.
(based on the presence of the scale engineer. For something designed to run for at least three weeks continuous while making no noise to speak of, that's pretty good, size-wise.

Zakharra wrote:So there is one strike against it. Another strike seems to be its size. To make a stirling capable of delivering a good amount of HP/DP (dragon power) it sounds like the thing would be -huge-. Too big to be viable for manufacturing factories. Steam engines can be made smaller and given OWLs information database, a lot more efficient for its size.

Have you ever seen stationary steam engines from the 1800s? They're immense. They were designed to be as durable and low-maintenance as possible, but they're nothing like compact. You could very easily get a 200 HP engine that was twenty feet high and made out of massive cast iron parts. (It would however run for years.)

The modern expectation of compact engines, derived from automotive applications themselves derived from aircraft where you just never run the thing for days, never mind months or years, doesn't apply to powering factories.

In the factory application, you care more about costs to run than size, and there the Stirling, inherently more thermodynamically efficient and inherently mechanically simpler, wins. It uses less fuel and less mechanic time and breaks less often.

Zakharra wrote:In your opinion, could a stirling deliver the HP needed to run the turbines/flywheel of a good sized factory to power the machines there and be smaller than the building the machines are in?

Sure. Remember, this was actually done in our history; Stirlings were used as stationary engines despite the efficiency problems (sliding seals, not knowing the thermo theory) because they were simple and low maintenance. Given a fix for the seals and some help from Owl with the thermo, it's really quite a no-brainer.

Zakharra wrote:A stirling locomotive? I can't see that being viable at all. A locomotive/train engine needs a LOT of horsepower in a frame small enough that will still fit on a car to pull the engine and cars behind it. In a steam locomotive, its the team that gives the power to move the wheels to pull the train. I cannot see a stirling engine producing that much power.

Why not? We're talking 1880s steam locomotives, here; ~200 psi, 25 tonnes max weight, needs to carry about as much water as coal. Locomotive power is generally given in tractive force, rather than horsepower, since power varies with speed. You don't need a 5000 HP diesel pulling 20,000 tons of unit train to get your railroads started.

Five hundred horsepower is probably too much in that application. That's certainly achievable, and you can use pneumatic or hydraulic drive to turn the wheels and pneumatic brakes. No boilers, no feed water, not fussy about fuel, and cheaper to maintain. A railroad ought to love that.

Castenea wrote:

Zakharra wrote: From what it sounds like, a stirling engine might be an efficient one, but it is not one that delivers a lot of HP which a steam engine can do. So there is one strike against it. Another strike seems to be its size. To make a stirling capable of delivering a good amount of HP/DP (dragon power) it sounds like the thing would be -huge-. Too big to be viable for manufacturing factories. Steam engines can be made smaller and given OWLs information database, a lot more efficient for its size. In your opinion, could a stirling deliver the HP needed to run the turbines/flywheel of a good sized factory to power the machines there and be smaller than the building the machines are in?

A stirling locomotive? I can't see that being viable at all. A locomotive/train engine needs a LOT of horsepower in a frame small enough that will still fit on a car to pull the engine and cars behind it. In a steam locomotive, its the team that gives the power to move the wheels to pull the train. I cannot see a stirling engine producing that much power.

I think you are a little off, although very large items often contain enough material to make them very expensive. I want to know if a Stirling cycle that could fit on a railcar have enough torque and HP to move a useful payload. Diesel locomotives will be a nonstarter on Safehold untill the proscriptions are overturned unless they go with hydraulic drive, as attempting to drive a locomotive with direct drive would require too many redirects and I do not believe that any clutch material would have a usefull service life.

The key is internal pressure and calo fluid. A stirlng using air and atmospheric pressure (18th) is very low power to mass. But they make fine stationery machines because of the running costs.

But the power increase a bit more than linearly with pressure, the limit is only on the seal tech. Modern stirlings are usually in the 5-12 bars range, and fairly easy to manage at those pressures, just need good steel for the hot end, possibly a graphite lined hot piston and adequate seals. Could go higher but seals efficiency vs friction problems become acute.

You need to start the engine at low pressure so have to provide a filling system.

Change working fluid to pure Nitrogen or better Hydrogen, and the output can triple or more if the regenerator is good enough. Seals for Nitrogen are easy, not so much for Hydrogen.

An hydrogen one running at twelve bars won't weight more than the equivalent IC one for the same output, especially in bigger sizes. There is no comparison with steam as the latter is much more inefficient and the weight of the water consumed alone is many times the weight of the engine.

They are high torque too, running at moderate speed (depending of the configuration). The only drawback of stirlings is that they are slow to throttle ( you need to change temp of hot end and/or pressure), but that is quite easy to manage with an hydrocoupler on the output.

alj_sf wrote:

Thucydides wrote:...
Stirling engines are still niche players (primarily used for AIP rigs on conventional submarines), but perhaps economic considerations might change to the extent that Stirling engines can move into other niches.
...

Early Stirlings had indeed bad power/mass ratios because of lack of low-friction seals allowing to pressurize them at least 5 bars. This is a solved problem.

Modern Stirlings with 10/12 bars internal pressure are quite good, but the IC tech is so developed everywhere that it is much cheaper to produce. Stirlings are also the most efficient engine possible.

The main use nowadays of stirlings is for cryo generation (used as motor) or as generators either in solar applications or cogeneration. There is a renewed interest for small stirlings (a few cc) where IC and diesel are very inefficient.

In Safehold case, IC is no go because of the electrical problem, and if Diesel can be made without, you have launch problems. Stirlings on the other hand, can replace any steam engine with a better efficiency (fuel economy) for a lower mass and insurance against boiler explosion. So there is no reason that in Safehold, they cannot become the main engine if the seals can be made. Teflon and the like are out of question of course but textile seals highly charged with graphite, while onerous to make should work.

Another advantage of stirlings is that they are extremely reliable.

How reliable are they when you thump them with a shell fragment? That would be a major consideration with warships. Every engine has weak points and points of failure where even the slightest damage cause critical kablooey but, overall, how does a stirling engine compare to a steam boiler for durability in the face of shock and damage?

alj_sf wrote:

Castenea wrote:I think you are a little off, although very large items often contain enough material to make them very expensive. I want to know if a Stirling cycle that could fit on a railcar have enough torque and HP to move a useful payload. Diesel locomotives will be a nonstarter on Safehold untill the proscriptions are overturned unless they go with hydraulic drive, as attempting to drive a locomotive with direct drive would require too many redirects and I do not believe that any clutch material would have a usefull service life.

The key is internal pressure and calo fluid. A stirlng using air and atmospheric pressure (18th) is very low power to mass. But they make fine stationery machines because of the running costs.

But the power increase a bit more than linearly with pressure, the limit is only on the seal tech. Modern stirlings are usually in the 5-12 bars range, and fairly easy to manage at those pressures, just need good steel for the hot end, possibly a graphite lined hot piston and adequate seals. Could go higher but seals efficiency vs friction problems become acute.

You need to start the engine at low pressure so have to provide a filling system.

Change working fluid to pure Nitrogen or better Hydrogen, and the output can triple or more if the regenerator is good enough. Seals for Nitrogen are easy, not so much for Hydrogen.

An hydrogen one running at twelve bars won't weight more than the equivalent IC one for the same output, especially in bigger sizes. There is no comparison with steam as the latter is much more inefficient and the weight of the water consumed alone is many times the weight of the engine.

They are high torque too, running at moderate speed (depending of the configuration). The only drawback of stirlings is that they are slow to throttle ( you need to change temp of hot end and/or pressure), but that is quite easy to manage with an hydrocoupler on the output.

One of the advantages of steam piston engines in locomotives is that they generate maximum torque at zero speed. Most other engines produce maximum torque at a significant speed above zero requiring a clutch to move the driven equipment unless a significant slip is built in (i.e. the water around a ship). Locomotives require large torque not large horsepower to move a mass from stationary.

AirTech wrote: One of the advantages of steam piston engines in locomotives is that they generate maximum torque at zero speed. Most other engines produce maximum torque at a significant speed above zero requiring a clutch to move the driven equipment unless a significant slip is built in (i.e. the water around a ship). Locomotives require large torque not large horsepower to move a mass from stationary.

Not exactly. A reciprocating steam piston generates 2 large impulses per turn that quickly drop to zero. If the driven wheel loose traction, the impulse is wasted. That is why you need a lot of sand on the rail on steam locomotives. if there is traction, the torque available is indeed big at any speed.

A Stirling run better with a flywheel like an IC engine, so the torque is constant in this case, but unlike the latter, the torque is directly converted from one impulse per turn (in a single unit system) without much losses and is pretty much the same at any speed.

If you run it without flywheel, the impulse is available on a much larger segment of the circle than with steam, and a 3 units engine will have big torque available all around.

More, by playing on pressure you can generate the exact amount of torque you need, decreasing the risk of the driven wheel slipping.

As I said before, the throttle control is however a bit lagging so you want either a clutch or better an hydrocoupler in the system. That add cost, but not that much.

I've never heard of putting sand on a rail. that seems like it would be counter productive and act as a lubricant rather than traction.

So far all I am hearing is that a stirling engine can give some smaller advantages in a stationary position, but I'm not hearing that they would be very efficient at the tech level Safehold is at currently. Right now Safehold has working steam engines, the stirling engine isn't viable yet (seal problems and possibly metallurgy problems in making it). Just because we can make a stirling engine effective now, doesn't mean they could then. The stirling seems to lack the needed oomph a steam and IC engine brings. I know people want working alternatives, but really we know what works and a stirling doesn't seem like it would be a fast engine. Slow as molasses comes to mind.

Yes the stirling can be more efficient on fuel, but at the tech level we are dealing with, fuel isn't a consideration because most things are so inefficient a few more % of fuel inefficiency isn't that much, if at all, of a cost consideration. Plus Safehold is trying to get to the higher tech levels as fast as possible and Steam is a lot faster in getting there than the stirling would be. The stirling seems more like a step sideways than forward.

One thing to consider why the submarine has some stirlings is noise. IC engines are noisy and a stirling sounds like it would be very quiet. And engine noise is a serious consideration on a submarine.

In the factory application, you care more about costs to run than size, and there the Stirling, inherently more thermodynamically efficient and inherently mechanically simpler, wins. It uses less fuel and less mechanic time and breaks less often.

I am not convinced that's true otherwise the factory owners in the middle to late 1800s to the early 1900s would have used the stirling. They were notorious penny pinchers. Many of them were extremely cheap in what they paid for factories, equipment and employees, and if a stirling would have come with operational costs significantly lower as you are implying, they would have been all over that in a heartbeat.