No geyser, no atmo suit, a flatulent Dupe and a Rocket Chimney

[Fradow]

Brace yourself, this is going to be a long read.
TL;DR

• Not using any geyser is totally possible, and not even that hard.
• Not using any Atmo suit is possible, but painful. Accommodating for Oxygen Masks makes flatulent Dupes mostly harmless.
• Warm Sweaters are under-rated when working in hot places
• A single Steam-powered Rocket in a Chimney can produce 1.5kg/s water

Exactly a month ago, I was challenged to make a petroleum loop or a rocket chimney to be self-sufficient in water, without ever using any water geyser.
Well, that was a bit easy, so I added other challenges on top of it: not using ANY geyser apart from Oil Reservoirs (required for a petroleum loop), and not using Atmo suits (apart from the one required to launch a rocket).
That second part about Atmo-suits turned out to be the real complication…

A late additional challenge was to take a flatulent Dupe, and of course let him go everywhere he pleased, otherwise it's no fun.

Since that forced me to get a bit off the beaten path and I discovered quite a few new things along the way, here’s a tale of how it went!

So how do you survive without geysers?

There are 2 resources you need to provide to your Dupes: Oxygen and Food.

Food is easy as there are multiple ways to produce food that do not use any resource or use worthless resources. I settled for a progression of Mealwood => Mushrooms => Slicksters and didn’t even mine out all the Dirt and Slime available. Slicksters, my renewable food source, are fed by Petroleum Generators exhaust and as such don’t consume any non-renewable resource. I could have gone with Pacus and/or Shove Voles as well, which can be ranched without providing any resource once scaled up.

The hard part is Oxygen. Let’s see the main possible solutions (exploits excluded):

• The Lavatory being power-positive, and generate enough water for 1 every 10 Dupes for free using that excess water. It’s not a lot, but it can help if your water budget is tight. I didn’t need to use it.
• An Ethanol loop can provide a lot of polluted dirt, which could be off-gassed to polluted oxygen then deodorized. A setup with 8 domestic trees, 4 ethanol distillers and 1 petroleum generator could provide for more than 10 Dupes while being slightly water-negative (which can be fixed by a few wild trees). Unfortunately, since Mergedown, that option is not viable in vanilla. It is in Spaced Out, but the same setup will only provide for 7 Dupes.

• A Petroleum Loop produces a decent water excess, at around 750g/s just for the Petroleum part, and a bit more when adding the Natural Gas from Oil Wells. All in all, you get around 7 Dupes worth of water from a full 10kg/s petroleum loop. That was my main goal. As it doesn’t use anything novel, I won’t be detailing it.
• A Sour Gas loop produces a huge water excess (probably in the range of 3x more, I didn’t calculate), but is more complicated to set up. I didn’t choose to pursue this path because I had no interest, but it’s a valid path to get more Dupes.
• A Rocket Chimney, which allows launching a Rocket from the depth of your asteroid all the way to space, producing exhaust Steam all the way and ending being vastly water-positive, even after refueling. That’s the option I chose since it’s a rarely pursued endeavor, and I’ll detail it later in this post. My version using a single Steam rocket produces an average of 1.5kg/s (which can easily be multiplied with more rockets or Hydrogen rockets), the equivalent of a perfectly average CSV, or enough to oxygenate 13 Dupes.

That means with just a Petroleum Loop and a Rocket Chimney, I could have enough water to oxygenate 20 Dupes.

So how did the plan go? Read on!

Not using any geyser turned out to be the easy part: any random Terra seed has a lot of resources, and setting up a petroleum loop before exhausting them isn’t really hard. In fact, I didn’t even need to tap into any water outside of the starting biome. The only resource I needed to proactively look for was Algae.

In constrast, working in the Oil Biome without Atmo suits is hard. Dupes really don’t like temperatures above 70°C. There is a very important, very underused clothing item though: the Warm Sweater, which was the first MVP of that challenge. By adding insulation, it means a Dupe cannot get scalded by 90°C Carbon Dioxide for example, and a lot of other hot elements that have a low enough Thermal Conductivity.
On the other hand, dipping even one feet in 70°C Crude Oil is an instant burn, which makes construction challenging, and trips to the Triage Cot frequent.
The second MVP of that challenge was the “Wounded go to Med Bed” mod, which makes Dupes interrupt what they do and go to recover from all those burns.

This was the single major productivity hit of this colony (apart from having a low Dupe count): Dupes recovering in Triage Cots. Bubbles (my doctor) has seen every single Dupe. Multiple times. Her medicine attribute was raised from 0 to a staggering 17 (and will reach 20 with enough time).

Then there is the CO2 expulsion of Oxygen Masks. This means no permanent vacuum, no brittle liquid airlock, and any thermal insulation via vacuum would have to be imperfect and incorporate a permanent pump to re-vacuum after some CO2 got there.
This was a blessing in disguise, because it made the late addition of a flatulent dupe mostly trivial (except the farts in the liquid airlocks that caused liquid compression and tiles below to break… But that’s a minor detail).

Turns out, it’s possible to work in the oil biome, make a full petroleum loop including a boiler and a rocket chimney without any atmo suit. A few adaptations had to be made though:

• Digging up the Oil Biome had to be done very deliberately to avoid Dupes setting feet into crude too much, and paths leading to crude pools had to be closed off.
• The boiler counterflow heat exchanger had to be 1 tile high to avoid CO2 staying over the petroleum. All the CO2 got trapped into the switchbacks, which had no visible impact on performance.
• The heat spike had to be built fast to avoid heating the area too much and scalding dupes.
• Oil Wells had to be actively cooled to around 45°C to avoid scalding Dupes every time they went to relieve back pressure.
• Liquid airlocks that tended to heat up above 70°C had to be actively cooled as well, especially the ones leading to the Slickster ranch.
• The chimney had to be fully built before launching the rocket. Reparations that had to be done afterwards required an access close to the repair location and inflicted multiple burns unfortunately.
• Overall, a few hot spots with a heat-conductive enough atmosphere required burning Dupes to do renovations for badly planned things. That’s the cost of doing business.

The excavated oil biome, with an ATST for each Oil Well, and a very efficient petroleum boiler.

As for the actual Water generation of the builds, it went well, apart from 2 issues: a mass deletion issue in the petroleum generators room that I had to work around, and second-based timers being super unreliable, which meant using a water-clock for the rocket automation (thanks to @Saturnus for providing the blueprint).
Here are both issues for more infos:

 

Colony milestones: cycle 300 and cycle 640

The full petroleum loop got completed at cycle 300. Here is an overview of the asteroid at this time:

And a zoom on the core base, which was not very refined, but works decently well:

At that time, the base was already sustainable in Oxygen for 7 Dupes (you'll notice there is only 8 beds), and it was only a matter of time before the Slickster ranch was built.

Nevertheless, I pressed on to build the Rocket Chimney and be able to get more Dupes. At cycle 640, everything was completed and the base have been running for several dozens of cycles mostly unattended too. You can see the huge chimney on the left:

The Slickster ranch was completed too, for a fully sustainable food source:

And the core base ... didn't change much. It's a game of spot the differences:

Want to see it in action? Here is the cycle 640 save file. Hopefully none of my mod will prevent the save file from loading.

No geyser challenge Cycle 640.sav

Details about the Rocket Chimney

My goal was to have a solution that was simple and predictable.

It’s far from optimized, but it works well and was a good foray into rocket chimneys.
To be able to trap as much Steam as possible, the chimney was made as tall as possible: from just above the core to the limit of the constructible area.
For the same reason, the use of space scanners was abandoned: space scanners have a delay that makes it impossible to accurately have bunker doors close just after a rocket return. Instead, I used a timer-based automation that had to rely on a water-clock because of the aforementioned issue.

The water-clock version is also much simpler, so it was a good move anyway.

I timed precisely everything in sandbox to be able to configure the automation accurately: it takes a whole 2588s from a launch to the next launch, so I rounded it up to 2600s to account for slight deviations, which is 4.33333 cycles.

The automation is based on the time the bunker doors need to be opened to allow the rocket landing: it closes doors just a few seconds after the rocket passes through them (a few more seconds had to be added because of buffer gates imprecision).

There is then a 752s delay (7.52kg on the right hydro sensor) which accounts for rocket landing, refueling, and start opening the bunker doors so that they are fully opened when the rocket can launch again. A few seconds again and they start closing just right when the rocket passes through.

The cycle repeat after 2600s (25.98kg on the left hydro sensor) which resets the water clock and prepares for the next rocket landing.

The rocket is refueled by pumping its exhaust back into it. There is a safety buffer of 4 gas reservoirs to cover several failure cases, that has to be initialized with an external Steam source (in my case, I re-used a design covered in my end-game guide). Enough Steam forms there to not need any trapping mechanism.

The Steam from the chimney is collected by 4 identical harvesting modules spaced along the chimney. They consist of a single SCST that has a mechanism to cool down steam it gulps down to prevent overheating.

All in all, this rocket chimney, once ramped up to its stable state, cranks out 1.5kg/s of Steam (measured over 12 consecutive launches, a period of 52 cycles), enough to oxygenate 13 Dupes. The power return is negligible and I didn’t not bother measuring it.

If you want power, you need to switch to Hydrogen Rockets, but that means a more complicated harvesting system because the Steam is super hot.
If you just want more water, you can add several rockets in the same chimney, but the automation has to be improved to handle that.

Conclusion

I now consider this challenge over. The colony is decently stable and won’t have any Food or Oxygen issues anytime soon. It could welcome more Dupes (it's currently at 12 Dupes), but I have no interest in expanding the core base to actually do that.
It can run hundreds of cycles with minimal intervention. Some process aren’t perfectly stable and will break given enough time, but those count under “minimal intervention”:

• Slicksters output isn’t properly handled. It’s minimal, but bound to overflow either the crude pools or make the petroleum reservoir back up. It has to be used somewhere, or stored in an infinite storage (I didn’t make any of those).
• Since Dupes don’t use all the available Water, the Rocket Chimney is bound to keep producing Steam, which has to be redirected somewhere, or a mechanism to auto-stop it has to be put in place.
• The Rocket Chimney isn’t 100% stable: the aforementioned timer issue, even if mitigated, can still occur, especially with late-game lag.
• An ill-timed Meteor could entomb the rocket and ground it until it’s cleared. A Robo-Miner could be added to mitigate that issue.

Barring Dupe stupidity, those are the main potential issues I identified but won’t be resolving, because it’s frankly a chore and I’m moving on to other more interesting projects (finishing my end-game guide being the top one).

Thanks to everyone who followed my adventures on Discord, and provided help with some of the sticky situations, and moral support for going through with that “troll challenge”, as it was called by its issuer.

 

[JRup]

This is the good stuff...

ONI still is what one makes it up to be. Still gets my appreciation for that.

Some time ago I did see something interesting that pushed the hydra concept onto the petro-gens... Temperature seeding seemed to be the limitation/stumbling block in said build before it's up and running...

It does look like a terra start (haven't downloaded the savefile...) so spamming oxyferns doesn't seem to be an early game/short term option, but I do guess that switching to offgassing polluted water (+deodorizers) once you've "stumbled upon" regolith seems rather viable for "O2" generation. (Thus subbing in for the paltry output of "polluted durt" -- "we know the author scenario")

Flatulent dupes aren't the plague people make them up to be (they do represent additional work in builds, though; extra extra kudos for not designating restricted access to them).

 

 

[Fradow]

The Petroleum generators hydra design is interesting. Though yeah, building it in survival has to be a pain, and a 150°C+ Peroleum requirement isn't great: it requires a less efficient boiler (in this instance, the boiler was so efficient temperatures were sometime below 125°C, and never above 135°C).

It is indeed a Terra asteroid (sandstone start), Oxyferns weren't an option, and I didn't want to abuse the pod too much by taking oxyferns/arbor acorns/pips (I did take a pip or two but didn't actually use them).

Offgassing polluted water would have been a viable solution. I didn't talk about the water => oxygen conversion because it's a well-known subject already. It would have been trivial to use Carbon Skimmers to pollute water and do an off-gassing => Deodorizers setup instead of an Electrolyzer setup. I used the Electrolyzer setup out of habit and convenience.

[JRup]

9 hours ago, Fradow said:

Though yeah, building it in survival has to be a pain, and a 150°C+ Peroleum requirement isn't great: it requires a less efficient boiler (in this instance, the boiler was so efficient temperatures were sometime below 125°C, and never above 135°C).

I've found that, instead of boiling the crude oil, a flaker can be easily adjusted to meet petroleum temperature needs when they're higher than input... But then we meet the minor "5010 g/s gotcha" that's associated with this kind of setup.