A Boring Mars Base

[Oersted]

Ekramer, check out this thread from five years back for a discussion of the same subject:

https://forum.nasaspaceflight.com/index.php?topic=41427.2960

Lots of ideas of circular tunnels in various configurations.

[meekGee]

I am aware there is another thread on The Boring Company (TBC), but that has become mostly updates on current and future vehicular tunnel projects on Earth (which is all fine and good).  This is about how a standard 12’ TBC tunnel could be used as a Martian habitat, scalable to any desired volume.  I’ve been messing about with the idea for a while, so here goes…

The basic idea is of a spiral, one long tunnel that wraps around itself, getting larger each turn.  Short radial tunnels connect the rings of the spiral, allowing quick and easy movement around the tunnel system.  The central ring becomes the main corridor, with compartments in the inner and outer rings accessed via radial corridors on each end.
 
The picture below shows the general layout of one inner ring and two outer rings, with eight radial corridors.   Each ring has eight compartments with two units each.  Units have various facilities such as housing, fitness, healthcare, offices, laboratories, workshops, maybe even a farm.  I don’t know the minimum turning radius of a TBM, but what is shown is probably too tight.  Consider it a ‘condensed’ version for illustration only. 

 For size comparison:
- Mars base shown is 420’ across at its widest point (excluding ramps)
- Star Trek, The Next Generation (Enterprise NCC-1701-D) saucer is 1,460 feet x 1,210 feet
- The Pentagon is 1,400 feet from midpoint on one side to opposite vertex

You realize I hope that The Starship Enterprise and the Pentagon are imaginary, right?

[Ekramer]

Hi Ekramer, and thank you for all the work and thought you put into this concept.

I thought about something very similar a long while ago, I don't remember if I posted in the Amazing Habitats thread about it, but just to say that I agree with your idea. Long curved tunnels intersecting in various ways because that is just the way TBM's work.

If the ground is propitious for it, I think several layers of circular tunnels could even be a good idea.

A lot of people haven't realised that TBM's are absolutely the most efficient way of carving out pressurizable volume on Mars, using the bedrock itself as the building material. Luckily Elon saw it a long time ago, which is why he started the Boring Company. I think it was his friend Jurvetson who confirmed that in a documentary.

As I have said often, you shouldn't bring the building material to Mars, you should just carve out the building material that is already there.

This is what the first city on Mars is going to look like. Get used to it folks. Just like on Earth, we humans will start out living in caves.

Thanks Oersted, much appreciated.  I tried to keep up with that other thread, but it got so huge!  I do remember talk of a much larger tunnel, maybe 40’ diameter?  I wanted to explore what was possible with a more “boring” 12’ tunnel.  Bigger tunnels will be built over time, but you have to start somewhere.  I think 12’ gets you a long way toward habitation, even if it’s not “amazing”.

I agree that most people on Mars will spend most of their time underground for a long time to come.  You will just feel safer in such an unforgiving environment. 

[Ekramer]

Ekramer, check out this thread from five years back for a discussion of the same subject:

https://forum.nasaspaceflight.com/index.php?topic=41427.2960

Lots of ideas of circular tunnels in various configurations.

Thanks, I hadn’t seen that part of the thread.  Will check it out tomorrow.

[Ekramer]

You realize I hope that The Starship Enterprise and the Pentagon are imaginary, right?

Well, I must have a good imagination because I’ve visited the Pentagon IRL.  Or did I dream that? 

I even literally ran into Captain Picard once, in a newsagents near the Barbican.  Almost knocked him over.  I instinctively stood at attention and said “sorry Captain”.  He smiled and replied “at ease lieutenant”.  I beamed with pride and let him pay for his Woodbines first.  As he left he said over his shoulder “replicators can’t make these”.  I did the only appropriate thing in the circumstances, saluted and said “Sir!”  His driver drove off and that was that.

[spacenut]

If you make one long continuous tunnel, how do you get the dirt out?  Conveyor belt or a continuous run of electric dump trucks?  How do they get the dirt out of tunnels on earth?  I have seen conveyor belt systems but it will pile up on the end unless you can truck it away somehow. 

[Greg Hullender]

I think deeper tunnelling gets more challenging, but it may be worth it in some cases.

Not sure how it might work on Mars, but at a presentation I attended here in Seattle, we were told that the way costs work for underground parking is that P1 generally costs about as much as the floor directly above it. (First floor, in US parlance.) But every level below P1 costs square-root-of-2 times as much. So P3 costs twice as much as P1, and P5 costs 4 times as much as P1, etc.

[MickQ]

If you happen to find a mesa, or similar rock outcrop at or near to a viable water source then that could be a start point. Just bore straight through, clear out the debris and fit an airlock at each end.

For more space just turn the TBM around and go back the other way some suitable distance to the side of the first.  The tunnels could be joined using hand tools or machines small enough to fit through the airlocks eg. mini road header.

[Ekramer]

If you happen to find a mesa, or similar rock outcrop at or near to a viable water source then that could be a start point. Just bore straight through, clear out the debris and fit an airlock at each end.

For more space just turn the TBM around and go back the other way some suitable distance to the side of the first.  The tunnels could be joined using hand tools or machines small enough to fit through the airlocks eg. mini road header.

Yes, I started off thinking like that.  It has a certain simplicity, which is good.  But I was trying to solve several problems.

- There are no rock formations of the correct size where I want to build my base.

- I need two miles of tunnels, but don’t want to walk 40-50 minutes end-to-end.  Yes, bicycles or similar would speed things up, but my pathway is only 9’ wide.  There’s a reason why bikes and skateboards are not allowed in corridors.

- I build four tunnels 0.5 mile long each, and connect them.  I can now walk end to end in 10-15 minutes.  First problem solved.  But it still takes up to 30 minutes to get back to where I started.

- And now I need to turn my TBM around three times, requiring partial disassembly/reassembly each time.  I have increased construction complexity 300%, not a good trade-off.

- And also eight airlocks are needed instead of two, a 400% increase in single points of failure.

I’m sure a single long tunnel with an opening on each end is exactly what is needed for some use cases.  We use them a lot on Earth to go through or under obstacles rather than around.  I don’t think it is the best solution for a Martian base.

[Ekramer]

I think deeper tunnelling gets more challenging, but it may be worth it in some cases.

Not sure how it might work on Mars, but at a presentation I attended here in Seattle, we were told that the way costs work for underground parking is that P1 generally costs about as much as the floor directly above it. (First floor, in US parlance.) But every level below P1 costs square-root-of-2 times as much. So P3 costs twice as much as P1, and P5 costs 4 times as much as P1, etc.

This is a good point.  I once found a chart showing tunnel wall thickness needed for different depths.  The thickness went up very quickly, not linear at all.  In fact, deeper depths required completely different (i.e. expensive) materials to keep interior dimensions somewhat in line with shallower depths.

Lower gravity on Mars might make it a smaller problem, but it must be bigger than zero.  I’m assuming depth will still be an issue, eating up interior volume with thicker walls.  Also, thicker walls mean more use of hard-won resources.  A real-life example below says reducing the lining from 280mm to 250mm saved 2,700 square meters of concrete in a tunnel 6m diameter and 3km long. 

https://www.mottmac.com/en-gb/projects/northern-line-extension/

[BN]

We just need to send some small rovers out to find one the right size, use sealant and install a door I don't think it invokes any large scale construction. Send two 8m doors for an air-locked lava tube.

If not, just dig a hole using shovels, built a pit-house with a vertical entrance hole like the natives in NA.

You may get lucky and find a suitable one exactly where you want it.  However, you still have a big construction project to line the lava tube as Martian rock is toxic.  Any surface airlock would have to be anchored deep into surrounding rock to keep it from popping out like a cork.  And the other end would also have to be sealed.  A 20m diameter tube would need a 20m airtight seal at one end even if the surface opening is smaller.

I’m not sure if you jest about using shovels.  Conditions for pit houses have to be exact, weak enough to be shovelled but strong enough to not collapse.  On Earth those conditions are very rare.

it will involve some kind of shovel, whether that be electronic or hydraulic. yes, the tunnel walls would likely need to be sealed due to perchlorates. so you take surface sealant and 2 doors.

[Ekramer]

Ekramer, check out this thread from five years back for a discussion of the same subject:

https://forum.nasaspaceflight.com/index.php?topic=41427.2960

Lots of ideas of circular tunnels in various configurations.

Thanks Oersted.  I’ve looked at several designs in the link, it has been very useful.  I too started by thinking about a multi-level design and even did some simple drawings of a sloped tunnel.  I think a 1 in 50 slope is the maximum practical as shown below.  At this slope, a 1’ step would have to be added every 25’ and steeper slopes require even more steps at shorter intervals.

The reason is a flat floor in a straight sloped tunnel results in a trapezoid floorplan.  Even in a 50’ compartment you start to run out of floor at the far end.  Steps must be added to keep a practical amount of floor to stand on.

This results in a complex 3-D space that complicates room layouts and built-in furniture.  Add in the curvature of the ring (which I have ignored here) and interior design becomes very difficult indeed.   I’m not saying it’s impossible, but in the end I believe a ‘flat’ base is preferable to a sloped one.

If multiple levels are desired, I would take the inside ramp downward rather than up, then build the lower level on the same plan as the one above.  You could technically build lower levels on wildly different plans.  But various studies have shown this induces low level anxiety, a sense of always being lost, never sure if you can get back where you started.
 
This is one reason why I settled on a single central corridor, you will always automatically arrive back ‘home’ within about 10 minutes.

[Twark_Main]

interior design becomes very difficult indeed.   Im not saying its impossible, but in the end I believe a flat base is preferable to a sloped one.

I'm not saying this is necessarily a bad decision, but this is what happens when the interior designer is the one calling the shots. 

See attached.

[InterestedEngineer]

what is the minimum turn radius of a Boreing machine?

[Ekramer]

What motivates having all the spirals at the same depth?

To add to what I have said above, I think the deeper you go, the further you are from a surface dome.  While these domes are rather small at 12’ diameter, one is never far away.  A five minute break is all you need to stretch your legs, climb a short ladder, and be immersed in endless landscape.  If you are three levels down, it will take you more than five minutes just to get there.

[Ekramer]

interior design becomes very difficult indeed.   Im not saying its impossible, but in the end I believe a flat base is preferable to a sloped one.

I'm not saying this is necessarily a bad decision, but this is what happens when the interior designer is the one calling the shots. 

Yes, but the opposite is also true.  Interior designers can 'fix' perfectly valid engineering decisions that just look odd or are unsettling.  Long hallways in hotels often have fake fire doors or columns that break up unsettling long and narrow lines of sight. 

I worked at a hotel where they called in a specialist because every weekend someone would  come out of the lift on one floor, turn the corner, and vomit.  Different person every time, but same place.  A picture was added at a certain spot with a certain size, shape and color scheme.  Never happened again.

Something about having a few drinks and turning left, then right, then long view with a lighted sign across the street.  The picture grabbed attention just long enough for the woozy brain to catch up. 

[Ekramer]

what is the minimum turn radius of a Boreing machine?

I don't know and I haven't found answer despite looking for some time.

[Twark_Main]

interior design becomes very difficult indeed.   Im not saying its impossible, but in the end I believe a flat base is preferable to a sloped one.

I'm not saying this is necessarily a bad decision, but this is what happens when the interior designer is the one calling the shots. 

Yes, but the opposite is also true.  Interior designers can 'fix' perfectly valid engineering decisions that just look odd or are unsettling.  Long hallways in hotels often have fake fire doors or columns that break up unsettling long and narrow lines of sight.

A closer analogy would be an interior designer empowered to eliminate the long hallway entirely, so they never need to worry about the "perfectly valid engineering decisions" saying a long hallway is actually best.

Ironically, we're both arguing that it's better when interior designers operate within externally-imposed constraints.


Anyway it's just something to keep in mind. When designing I try to give the other disciplines extra "breathing room." The less I understand some area the less likely I am to take shortcuts or assume miracles or pull "design points" from that area, rather than more likely (which seems to be a common tendency).

[catdlr]

what is the minimum turn radius of a Boreing machine?

I don't know and I haven't found answer despite looking for some time.

The Hawthorn test tunnel was 500ft.  I could not locate any customer user guide or brochure other than the company website, but they do offer "Burnt Hair"

https://www.reddit.com/r/BoringCompany/comments/gr1gm1/what_is_the_turning_radius_of_a_tbm/?form=MG0AV3&form=MG0AV3

https://www.boringcompany.com/prufrock?form=MG0AV3

[Ekramer]

what is the minimum turn radius of a Boreing machine?

I don't know and I haven't found answer despite looking for some time.

The Hawthorn test tunnel was 500ft.  I could not locate any customer user guide or brochure other than the company website, but they do offer "Burnt Hair"

https://www.reddit.com/r/BoringCompany/comments/gr1gm1/what_is_the_turning_radius_of_a_tbm/?form=MG0AV3&form=MG0AV3

https://www.boringcompany.com/prufrock?form=MG0AV3

Ah, I just found a planning document for the test tunnel at:
https://hawthorne-ca.granicus.com/MetaViewer.php?view_id=&event_id=465&meta_id=32264

The important pages are Exhibit A & B shown below with the following underlined
"HAVING A RADIUS OF 530.00 FEET"

This is not necessarily the minimum radius, but it sets a not larger than limit.