I started design work for the ship's engines by consulting data we'd collected on ambient mana from before our rge crystal was installed. Rather than power the ship with charcoal coal, like the old steam engine I'd put on the old boat, I'd much prefer to run it on mana. There are a few problems with trying to run it on mana, however, that I'll need to overcome. First, while our isnd has very high mana due to the rge mana crystal, I suspect that there is likely an area of low mana around the isnd. If we compound that with the mana levels at nighttime versus daytime, the different conditions that the engine will need to operate in will be very rge.
The engine I design doesn't need to run at full power during low mana conditions, but it does need to be able to work. In short, the operating conditions can have quite a wide possible range, and we need to ensure that it'll work in any of them. To do that, I've started the excavation of a new underground b area at a depth where the mana level is about 20% less than the lowest mana level we ever recorded. That record occurred at the coinciding of the three events that lower the mana level naturally: nighttime, a sor-sor eclipse, and a sor-lunar eclipse.
The general design for the system I have in mind is somewhat convoluted, but each part can generally be tested individually making the process a little easier. There are four main components and a handful of supporting components beyond that. The main things we need are a desalination pnt, a condenser, a boiler, and the steam engine itself. The desalination pnt will be necessary to make the freshwater to repce any losses accrued through the rest of the steam system, the condenser recovers the steam we're already making back into freshwater, the boiler produces the steam, and the engine converts steam pressure into work.
For the most part, the steam engine and condenser are mundane, and are pretty straightforward to make. The boiler and desalination pnt, however, are the parts that I intend to make powered by mana. For the boiler, I'm thinking of taking a number of very thickly cut heat fluorite ptes completely embedded in a copper heatsink and putting them vertically on the inside of the boiler. The thickness of the fluorite and the number of ptes will be dictated by the need to bring enough water to a boil to sufficiently drive the ship in low mana conditions. The desalination pnt is mostly the same, but will be kept at a retively lower temperature and won't be pressurized.
The main issues that I see possibly arising from the design are that I know firsthand that too many fluorite crystals in a small area all compete with each other to drain the local mana, and that I can't really know how much of an affect the water will have on the mana bance of the system. Ocean water, and water in general, seems to act like a conductor for mana to a small degree, which could cause the system to have far more mana than I expect once we're out on the open ocean.
To compensate for that fact, I'm pnning on designing the condensers to be able to handle a significant amount of steam and to be able to completely flush the boilers with continuous saltwater as needed. If the fluorite gets suddenly flooded with mana, we might end up venting steam to relieve pressure, and I really do not want the fluorite to melt, which would permanently destroy the functionality of the boiler.
I'll only get to start tinkering here with the physical components in 8 or so days, when the area is fully excavated underground. They've been working on it for 15 days already, and I've had a discussion with Zeb about where construction teams should go for the next while. After this b area is dug out, the drydock and locks are upgraded, and the nitroglycerin pnt is fully online again, we're going to resume housing construction, finish the methanol facility, and recover more of the crystal material from old crystal pockets.
Popution growth is still vitally important for us, as each of these ships is likely going to take over 100 individuals to operate. Since it's already so close to completed, methanol will open up some precision heating options that we might end up using in the near future, especially for things like fluorite crystal growth that could improve future steam engine designs. Finally, the crystal material is necessary because we've used quite a bit of it to make hardened steel for tools, and I still have some more tools that will need it. I'm pnning on trying to design a pneumatic rivet gun which should drastically improve assembly speeds for the ship.
I made some interesting discoveries while attempting to design the boilers for the ship. My initial concerns reted to the total avaible mana had me concerned after I struggled with producing the amount of heat I'd hoped for. As the number of thick ptes increased, each pte became less effective. However, they didn't become linearly less effective. There appeared to be an s-curve in the data, where below a certain amount, each crystal acted as if no others were nearby, and then below a certain point, they again started to neglect the effect additional crystals would have on their individual efficiency.
As the saying goes, nature abhors a vacuum, and that seems to apply to mana too. Intrigued by the result in the b, I decided to do a simir test, but along the coastline. Rather than try to use some other form of fluorite, and wait for the growth period, it was faster to set up a chamber along the stream where the copper could transfer the heat from the fluorite to the water, effectively cooling the system. What I found there was that, after accounting for the surplus mana due to the mana crystal, the amount of fluorite necessary to start feeling the affects of very low mana was much higher. In essence, the s-curve was spread much further, with a much more shallow slope.
That makes some sense to me, considering the b is underground, surrounded by partially shielding rock. Even if the natural resting mana in the room is low, that doesn't mean that the rate that mana replenishes is at a directly proportional rate. In short, while the b has certain benefits operating at that depth, it doesn't actually convey the conditions that I'd expect to experience in a low mana environment on the ocean. I took a total of 45 days collecting various data points until I was confident on a new b depth that would more accurately represent the avaible mana flux rate I'd expect for the size of boiler I'd like to make.
When factoring in losses of efficiency and operating conditions, I'm pnning on each of the two pairs of steam engines and boilers to produce about 10 megawatts of power. In low mana environments that falls to just a few hundred kilowatts, but that should still be enough to move the ship forward, though some auxiliary systems might end up having to be shut down. Most of the power will go to the propellers, but I pn on having a few gears that can be meshed onto the central driveshaft to drive some of the pump systems and an alternator that can produce useful electricity which we can run to other parts of the ship to power local devices. The mechanical gearboxes and other such systems are going to require some actual skill to operate for a ship this size.
After another 30 days, I've now got a b fitting the low end conditions I expect on the ocean and an above ground facility near the ocean that mimics the highest end conditions I'd expect to experience. I had thought I'd ran into a concern reted to counter-flow heat exchange using sea water to cool steam back down to water, but the problem sort of solves itself. The main concern I had was reted to higher temperature ocean water. When the incoming ocean water is hot enough, we condense less steam back down, which had me worried that we'd have an operating issue if I could recover that water somehow.
As it would turn out, however, that also means it takes less energy to get the ocean water to boil, meaning we make more freshwater. In essence, the differential is something of a self-correcting mechanism, as long as the desalination pnts are appropriately sized. Perhaps it's thanks to not needing to carry fuel, or maybe it has to do with fluorite/copper heaters being less heavy than a firebox with the extra mechanisms necessary to operate it, but my expectation for the weight of the main equipment for the ship is reducing a little bit. Once I actually have some full sized prototypes made, I'll be able to get a better estimate. One of the big driving factors for total weight might end up being the devices that do force transfer from the engines to other components and regution of speed.
