Author’s own photo
The previous article on this project did reasonably well, so I thought I’d expand on it, showcasing some of the pictures and other details left on the cutting room floor. Many of the prototypes and spin-offs didn’t really fit into the narrative, the purpose of which was to give a Cliff’s Notes version of Hampture to bring newcomers up to speed, so we’ll look at all the leftovers here instead.
The Hampture project is, as of this writing, in it’s 11th year. The idea occurred to me in 2010, though versions of it were swirling around in my brain as far back as grade school. There’s more examples of rodents living underwater in popular fiction than you might expect, and besides that, I had a more general interest in hostile environment habitats of all kinds.
Space, underwater, underground, Antarctica. The tantalizing vision of humanity enveloped within a technological bubble furnishing absolute safety and comfort in an environment that would otherwise kill us. I was, as you might expect, a voracious consumer of all information related to manned spaceflight. The problem was, there’d not been much of it by that point, so I soon ran out of material.
Author’s own sketches
This turned me on to undersea habitats. Fascinating in many of the same ways as space stations or lunar colonies, but because they’re dramatically cheaper to build and emplace, there’s been far more of them. I at once began sketching out my ideas for human scale habitats made using materials I thought would be affordable to get my hands on.
To my dismay, when I began investigating why there weren’t already underwater cities, I learned about all the incredible challenges involved in establishing even modest amounts of dry, shirt sleeves habitat space underwater. A crushing blow, but it didn’t discourage me for long.
I have never been content with pipe dreams. Even my flights of fantasy have to be grounded in valid physics and workable engineering, or I can’t enjoy them. I wanted to solve all these problems so that one day, anyone who wanted to could live underwater. But I couldn’t afford to build full sized habitats.
Author’s own sketches
What do train enthusiasts do if they can’t afford full sized trains? They build functioning model trains that operate based on the same principles. Likewise with RC airplane and helicopter enthusiasts. Recreating the object of your fascination in miniature scratches that itch, but also teaches you in a hands-on way about how it works.
It can even lead to ideas for how to improve the real thing. For example during my experiments with these scale model habitats I worked out that ballast was the single biggest expense. Simply moving the tremendous about of weight over land from the point of origin, to the shipyard, then out to sea where the habitat will be sunk.
The solution to this, which I later learned wasn’t my own innovation but had already been used by a few experimental habitats, is to source ballast weight from the seafloor where you mean to sink your habitat. Specifically using a dredge pump to bring up seafloor sand, which is what then weights the habitat down.
Author’s own sketches
Studying submersible docking solutions also furnished me with ideas for how to improve upon moon pools such that submersibles can be brought up into a completely dry space where disassembly for maintenance and repair is possible. Conshelf 2 accomplished this with a winch, but it seemed to me you could also just design the moon pool module to flood for ease of entry by the sub, then purge it once inside.
It also gave me ideas for self-sufficiency. That’s a huge fixation people have when it comes to living underwater. I don’t know why, there’s no such thing as a self-sufficient city, even on land. Yet for some reason it’s popularly imagined that if an underwater settlement isn’t self-sufficient, there’s no point.
At the end of the day you have to give people what they want. They demanded modular tubes for connecting habitats, so I devised modular tubing for connecting habitats. They demanded I investigate self-sufficiency, so I investigated self-sufficiency.
Author’s own photo and sketches
This came in the form of algae cultivation experiments, and “naturalistic habitat” experiments wherein the substrate material is soil that small plants like grass or clover are seeded in. The idea in one case being that if you circulate air from the habitat through a jug of algae saturated water, the algae will consume the CO2 and add back O2.
The idea in the other example being that if the substrate is soil with plants growing in it, feces and urine will be consumed by the plants which in turn will scrub CO2, generate oxygen and act as a supplementary food source. It all sounds ideal on paper, but implementing it proved more difficult than expected.
Bioregenerative life support is far from a solved problem. It’s the sort of topic MIT guys write their thesis papers on. NASA has a department studying it full time. It’s very promising but also very difficult to strike a sustainable balance with living things in an enclosed space.
Author’s own photos
Plants grew well enough in that environment. I didn’t use moisture traps on their air lines, so they got especially humid air, and it’s been known since Conshelf 2 that plants do well in even slightly hyperbaric conditions owing to the greater concentration of CO2 (and all other constituent gases for that matter) in the habitat’s internal atmosphere.
Watering them wasn’t a problem. Some designs exposed the roots to the water outside. Others involved systems for injecting water into the air line, letting pressure from the air compressor push it down into the habitat. In every case, mold became an insurmountable problem.
It turns out warm, humid conditions are not only the favorite of leafy green plants, but mold as well. The algae cultivation approach hit a wall when keeping the algae alive, in a jar, underwater proved uneconomical in terms of the energy cost of additional LED illumination, thermal regulation, etc.
Author’s own images
The enclosures originally used to cultivate plants were recycled and repurposed into hamster micro-habitats. Not intended for serious use but to test out individual design features I wanted to use in larger, long term habitat modules. For example private sleeping pods (left) and vertical climbing tubes (right). It was important to see how (or if) hamsters would utilize them ‘in situ’.
These prototypes also taught me lessons about air inlet positioning. Incoming air is cold, in the cylindrical habitat on the right it’s pointing straight down at a heated pad where the hamster might otherwise prefer to sleep. There was a second heated pad on the lower floor so I could observe what choice the hamster would make and in turn how much or little the inlet bothered him.
During this experimental design period I also toyed with micro capsules, not habitats at all but potential cockpits for an eventual Hamsub. I did attach one of these capsules to a toy RC sub but as it still needed to be tethered to the surface via an air line to receive fresh air, I shelved the concept until I could devise onboard compressed air storage.
Author’s own images
Hamsub Mk. II is still planned for the future but will require a staggeringly expensive proper ROV (underwater drone) as the foundation. Once that’s in my possession I can devise a mounting solution for the Aqua Bubble, my favorite of the cockpit/capsule designs that I devised during that time.
After I got all of these tangential micro habitat projects out of my system, I turned toward the future of the project and got serious about how to build a much larger, more capable long-term submersion platform. Something with more than one room, more space to move around, more comforts & amenities.
This is where the Mk. III came from that I already showed photos of in the prior article, but it wasn’t the only design I considered. There were many alternative configurations I looked at before I decided for sure which one I wanted to go with:
Author’s own sketches
This is what set me on the road to building the Mk. III and learning by direct experience that mounting all the modules to a single rigid platform wasn’t the way forward. I’d been trying all that time to avoid the difficult problem of devising a modular tunnel system, but lugging the big, heavy Mk. III prototype into and out of that pond drove the point home for me: Modular tunnels were an absolute necessity for any of this to be practical.
This was also around when I began revisiting the concept of a human scale habitat for myself. While the initial discouragement from learning about the cost and challenge of establishing underwater living spaces made me content to focus on scaled down models, the more I tinkered and solved design problems on the hamster scale, the more feasible it seemed to do the same on the human scale.
I busted out Maya and dusted off my disused 3D modeling skills, exploring different concepts for human scaled habitation modules based on the lessons I’d so far learned by tinkering with these functional scale models. It seemed to me there was plenty of room for cost reductions to be realized, with some pretty simple design changes.
Author’s own renders
As yet I’ve not been able to raise funding to a level that would permit human scaled habitat design exercises like these to be implemented irl. But it goes to show how creative cross-pollination can occur when working on two closely related projects simultaneously: Lessons learned from one can often be applied to the other, and vice versa. In fact, taking a break when stuck on one problem to revisit the other can turn out to serendipitously reveal the solution you needed.
This is how I came to begin work on a surface supplied diving helmet. It occurred to me that the exact same principles my habitats were based on could be applied to building a weighted, windowed helmet fed a constant supply of fresh air from an electric compressor on the surface via a long hose, as my habitats were.
In fact this wasn’t anything new. It’s how diving used to be done prior to the invention of scuba. My only innovation was to make it solar powered. The helmet’s square sided because I learned from curved versus rectilinear habitat enclosures that curved transparent acrylic behaves like a fish eye lens underwater, distorting everything seen through it.
Author’s own photos
One step closer to my own underwater base. Really, what’s a positive pressure underwater habitat but a diving helmet, scaled up? What is a surface supplied diving helmet, but a scaled down diving bell? By gradual, cautious experimentation and evolutionary iteration, I’ve been inching closer and closer to realizing my dream.
It’s remarkably similar to how (IIRC) one of the Apollo astronauts described how he made it to space. It wasn’t all in one big leap but a lot of little steps. Every time he had a choice between two or more paths, he chose whichever path got him a little bit closer to where he wanted to be. After doing that enough times, he found himself strapped into a rocket headed for the Moon.
An appropriate comparison as what I’m doing here has been likened by others to a “miniaturized space program for rodents” along with all the safety precautions, iterative prototyping and so on that goes into it. But really my goal is much humbler than that. Just a little comfy pod under the water with a big window I can look out at the fish through.
Already I’m so close I can taste it. But before I can venture into the deep, first to visit and then to stay, hamsters will go in my stead. Because before I can choose the impossible, I must choose Hampture.
As before, you can find the Youtube channel for this project as well as live Twitch streams of the underwater habitat in an aquarium, a merch store and everything else related to the project at this link.