Advanced tech without electricity/internal combustion?

Weird Harold wrote:

n7axw wrote:The Twin Cities Automotive Plant built Rangers right up to the time when the model was discontinued.

Ya-no, they might still be making Rangers if you guys bought new ones more often than every 20 years. :p

I saw an attempt to redirect the thread, but I wonder if we shouldn't post a new thread to determine the demographic weight of current and former Ranger owners.

I admit that I have a 97 Ranger with 155,000 miles.

Back on target...

I was drawn to this thread at first because I am writing a bit of original fiction where the world has very few free metals. Trying to imagine different ways to implement technologies without metal is tough, tough, I say!

Something I haven't seen mentioned here, which WILL find it's way into my work at least, is using Fresnel lenses for a power source for simple steam-power.

Fresnel lenses would also (if you have metal) be viable energy sources for Stirling engines. Again, immobile platforms.

Am I mistaken, or has there been a mention of Fresnel lenses for power sources on Safehold? We know the population can make corrective lens eyeglasses...

Cheopis wrote:Back on target...

I was drawn to this thread at first because I am writing a bit of original fiction where the world has very few free metals. Trying to imagine different ways to implement technologies without metal is tough, tough, I say!

Something I haven't seen mentioned here, which WILL find it's way into my work at least, is using Fresnel lenses for a power source for simple steam-power.

Fresnel lenses would also (if you have metal) be viable energy sources for Stirling engines. Again, immobile platforms.

Am I mistaken, or has there been a mention of Fresnel lenses for power sources on Safehold? We know the population can make corrective lens eyeglasses...

To the best of my knowledge, no mention of Fresnel has been made, and a quick search of the Safehold forum shows exactly one post with a match to Fresnel - yours.

Cheopis wrote:Am I mistaken, or has there been a mention of Fresnel lenses for power sources on Safehold? We know the population can make corrective lens eyeglasses...

No mention in Textev and no mention in the forums by name.

I think part of the reason is that using lenses of any kind to generate steam is strictly a small scale proposition. For any kind of industrial power you need acres and acres of solar energy collection and concentration.

Cheopis wrote:Back on target...

I was drawn to this thread at first because I am writing a bit of original fiction where the world has very few free metals. Trying to imagine different ways to implement technologies without metal is tough, tough, I say!

Something I haven't seen mentioned here, which WILL find it's way into my work at least, is using Fresnel lenses for a power source for simple steam-power.

Fresnel lenses would also (if you have metal) be viable energy sources for Stirling engines. Again, immobile platforms.

Am I mistaken, or has there been a mention of Fresnel lenses for power sources on Safehold? We know the population can make corrective lens eyeglasses...

For high energy densities mirrors work better because the energy does not need to pass through them. If you have metal a mirror just involves polishing. To make a Fresnel lens involves more energy than making a steel or silvered copper mirror and way more high purity resources (large glass Fresnel lenses are HEAVY (if several orders of magnitude lighter than a solid lens)). Light weight Fresnels are only possible with high transparency polymers and precision machined micro finished molds - well beyond Safeholds current tech level. (Glass is very poor at taking on fine detail in molds due to its surface tension and brittleness).

Weird Harold wrote:

Cheopis wrote:Am I mistaken, or has there been a mention of Fresnel lenses for power sources on Safehold? We know the population can make corrective lens eyeglasses...

No mention in Textev and no mention in the forums by name.

I think part of the reason is that using lenses of any kind to generate steam is strictly a small scale proposition. For any kind of industrial power you need acres and acres of solar energy collection and concentration.

Indeed, but you also don't need fuel, though maintenance is necessary. I'm not sure that the total footprint of solar heat transfer systems is too much greater than other methods, if you include all the input streams. You can't get the same degree of efficiency, but there's no fuel.

Cheopis wrote:Indeed, but you also don't need fuel, though maintenance is necessary. I'm not sure that the total footprint of solar heat transfer systems is too much greater than other methods, if you include all the input streams. You can't get the same degree of efficiency, but there's no fuel.

Just as an example since it closed down 15 years ago:

The project produced 10 MW of electricity using 1,818 mirrors, each 40 m² (430 ft²) with a total area of 72,650 m² (782,000 ft²). Solar One was completed in 1981 and was operational from 1982 to 1986. Later redesigned and renamed Solar Two, it can be seen from Interstate 40 where it covers a 51 hectare (126 acre) site, not including the administration building or rail yard facilities shared with a neighboring plant. Solar One/Two and other nearby solar projects are plainly visible via satellite imaging software at 34°52′18″N 116°50′03″W.

More at: http://en.wikipedia.org/wiki/The_Solar_Project

Also: http://en.wikipedia.org/wiki/Solar_power_tower

Concentric rings of mirrors focused on a common point is a similar principle to a Fresnel Lens, but they can be made much bigger and much cheaper than a Fresnel lens.

On your metal-poor world, optical quality glass might make sense, but Safehold isn't metal-poor so metal mirrors or glass mirrors with metal "silvering" would be far cheaper and manageable than lenses. Especially if you want something bigger than a solar "easy-bake Oven(tm)"

AirTech wrote:

Cheopis wrote:Back on target...

I was drawn to this thread at first because I am writing a bit of original fiction where the world has very few free metals. Trying to imagine different ways to implement technologies without metal is tough, tough, I say!

Something I haven't seen mentioned here, which WILL find it's way into my work at least, is using Fresnel lenses for a power source for simple steam-power.

Fresnel lenses would also (if you have metal) be viable energy sources for Stirling engines. Again, immobile platforms.

Am I mistaken, or has there been a mention of Fresnel lenses for power sources on Safehold? We know the population can make corrective lens eyeglasses...

For high energy densities mirrors work better because the energy does not need to pass through them. If you have metal a mirror just involves polishing. To make a Fresnel lens involves more energy than making a steel or silvered copper mirror and way more high purity resources (large glass Fresnel lenses are HEAVY (if several orders of magnitude lighter than a solid lens)). Light weight Fresnels are only possible with high transparency polymers and precision machined micro finished molds - well beyond Safeholds current tech level. (Glass is very poor at taking on fine detail in molds due to its surface tension and brittleness).

True, but sand is really easy to mine, and you don't have to do it with fine glass. Large building with a heavy duty frame. Then, instead of a normal roof, you put in a bunch of angled glass blocks instead of tiles.

Every row of tiles would have glass blocks at a slightly different pitch. This creates a Fresnel lens as large as a building, with very crude glassmaking technology.

Of course, you would probably want the building to be a long building, with the center of the roofline carefully aligned with the sun.

You could probably design it to be slightly adjustable for the seasons, with wedges. The roof wouldn't need to be weatherproof, because nobody lives there. Since it's not going to be terribly efficient, no matter what you do, you don't have to keep it super clean. Spraying water on the roof at night should be enough to get most of the dirt off. Every now and then, send someone up at night with a mop to clean off the glass a bit better, if deposits start building up.

This would probably be more likely as a community project to provide heating and hot water for community use, but it could also be a single expansion steam power source for machinery if there was a good water source nearby.

Being able to keep huge amounts of metal shiny is not trivial with Safehold technology levels. Mirror technology before the 1900's was expensive. I believe that is because silver was used.

I'm fairly sure Safehold doesn't have easy access to large amounts of high reflectivity metal that is both low maintenance and cheap. That could change extremely rapidly though. They've got the beginnings of metallurgy already, and they are not inventing it all from scratch.

If Safehold were to seriously consider solar power, it would almost certainly be reflection based, because they have metal, and it wouldn't take long to come up with a good metal for mass-produced mirrors that would have a long life and be low maintenance.

That's not an option in the place I'll be writing about.

Weird Harold wrote:

Cheopis wrote:Indeed, but you also don't need fuel, though maintenance is necessary. I'm not sure that the total footprint of solar heat transfer systems is too much greater than other methods, if you include all the input streams. You can't get the same degree of efficiency, but there's no fuel.

Just as an example since it closed down 15 years ago:

The project produced 10 MW of electricity using 1,818 mirrors, each 40 m² (430 ft²) with a total area of 72,650 m² (782,000 ft²). Solar One was completed in 1981 and was operational from 1982 to 1986. Later redesigned and renamed Solar Two, it can be seen from Interstate 40 where it covers a 51 hectare (126 acre) site, not including the administration building or rail yard facilities shared with a neighboring plant. Solar One/Two and other nearby solar projects are plainly visible via satellite imaging software at 34°52′18″N 116°50′03″W.

More at: http://en.wikipedia.org/wiki/The_Solar_Project

Also: http://en.wikipedia.org/wiki/Solar_power_tower

Concentric rings of mirrors focused on a common point is a similar principle to a Fresnel Lens, but they can be made much bigger and much cheaper than a Fresnel lens.

On your metal-poor world, optical quality glass might make sense, but Safehold isn't metal-poor so metal mirrors or glass mirrors with metal "silvering" would be far cheaper and manageable than lenses. Especially if you want something bigger than a solar "easy-bake Oven(tm)"

I responded to this with the post immediately above this post, I think. Like mirrored surfaces, a large array of prisms could mimic a very large Fresnel lens, without metal.

The issue with solar, wind and virtually every other "renewable" source of energy is that the energy density is low, and the source is intermittent. Look at the example of Solar1/2 upthread. The plant covered 51 Hectares and only produced 10 MW of energy when the sun was shining. Your typical utility plant covers a fraction of the surface area, yet can produce energy outputs measured in hundreds of MW, or even GW, and they can do this 24/7.

Frankly, land is too valuable to be covered in mirrors, photovoltaic panels, Fresnel lenses and so on, particularly when there is no ROI when it rains or when the sun goes down. This is the same reason windmills are such a poor choice, since they only produce energy when the wind is blowing and the amount of energy can be quite variable over periods of minutes as the wind speed fluctuates. For every MW of wind turbines you have in production, you need a MW of simple cycle gas turbine generators (not the more efficient combined cycle generators) running on "hot idle" 24/7 to pick up the slack when the wind speed varies.

If metallurgy becomes more advanced on Safehold, they might consider using "supercritical" fluids in their steam machinery, since the devices become far more compact (compare a supercritical C02 turbine to a steam turbine), but this is much farther down the road than diesel engines or other such devices.

Finally, WRT diesel engines, the opposed piston configuration, such as the Jumo 205 provides a fairly rugged and high power output 2 stroke engine which was even light enough to use as an aircraft powerplant. Opposed piston engines like the Jumo or the American Fairbanks-Morse also dispense with cylinder heads, valve trains and several other potential points of weakness with regular engines, and their uniflow scavenged designs are fuel efficient and fairly clean, not having to mix lubricating oil with the fuel.


The Jumo design was built under license by Napier, which went on to build the rather awesome "Deltic" engine, by combining three sets of engine blocks, which was used to power locomotives and patrol boats. The ultimate evolution was to have been putting a Rolls-Royce Nene turbine in the center of the triangle driven by the exhaust gasses of the engine and producing an estimated 6000hp. The Napier engineers predicted the piston rods would fail at about 5300hp, but the engine was run up to 5600hp(!) before failing. More here:

http://atomictoasters.com/2011/01/the-napier-deltic/