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#251 2023-08-31 10:55:33

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,581

Re: Trains on Mars - Could a rail system provide martian need

Electric road trains.
https://www.lowtechmagazine.com/2009/07 … -1950.html

These were a German innovation in the first half of the 20th Century used for transportation of goods between towns and villages that were for whatever reason, not served by railways.  They were slow compared to modern trucks, but may have found favoured use in Germany because they were direct electric powered and did not rely upon oil derived fossil fuels.  Technologies like this could be in line for a comeback.

Something like this could be especially useful on Mars, once we begin construction of roads.  On Mars, liquid fuels must be manufactured from electricity.  It would appear far more efficient to use electricity directly for propulsion, without having to store it in fuels.  We could enhance this idea by installing a monorail down the centre of roads.  Electric trucks could then use the Ewing System, whereby wheels provide balance but the central rail carries most of the load.  The rail could also serve as the return or grounding phase for the current.  This allows relatively low voltage DC to be used, delivered by a cable suspended from a pole, maybe 15' above the road.  Electricity can jump ~1" per 10,000 volts.
https://1stelectricians.co.uk/blog/how- … city-jump/

Power =V^2/R.

So a conductor carrying 10,000 volts will need only 1/200th the area of a conductor carrying the same power at 700V.  So a steel DC cable 0.5" thick should be able to deliver as much power to a road train as a DC  third rail at 700v (2.5MW from memory).  And a 1" jump distance is no danger if the cable is 15' above the road and 9' above anyone walking.  On Mars, it should be possible to deliver power to the cable using direct solar panels along the length of the road.  The power and top speed provided would be a function of sunlight intensity.  Power would be highest at midday and would fall to zero between sunset and sunrise.

Last edited by Calliban (2023-08-31 11:15:50)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#252 2023-08-31 12:32:53

GW Johnson
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From: McGregor, Texas USA
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Posts: 5,618
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Re: Trains on Mars - Could a rail system provide martian need

This almost exactly what I proposed for Mars over in another thread.  On Mars,  you do road grading to smooth out the rocks a bit,  and just run big off-road tires on the sand.  There is no water to drain,  so the grade embankments on either side are your "track".  Make the tractor battery electric drive,  and hitch up a train of trailers behind it,  to carry freight.  Put solar panels on the roofs of the tractor and all the freight cars.  It's slow,  but who cares?  Put a blade on the tractor,  tow a trailer with a small reactor in it,  and that's your road grader.
Minimal human supervision,  minimal infrastructure investment,  maximal freight tonnage being hauled soonest by anyone's schedule.   Hardest part is carrying these big heavy vehicles to Mars and assembling them there.  Harsh environment.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#253 2023-09-01 02:36:24

kbd512
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Re: Trains on Mars - Could a rail system provide martian need

Calliban,

How practical is it to actually deliver 10,000V on a planet with an atmosphere choked with fine dust?  I'm far less worried about hurting someone out walking their dog near the train tracks than I am about arcing and sparking during a dust storm.  It probably won't physically damage the train, but what kind of power loss should we expect?  We must get some kind of benefit from having so little atmosphere and Mars being so dry.  Is it enough to offset the dust static discharge problem?

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#254 2023-09-01 06:56:35

tahanson43206
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Re: Trains on Mars - Could a rail system provide martian need

For kbd512 re #253

This post is not intended to offer an opinion one way or the other, but instead to applaud the opportunity you have provided for Calliban to develop his idea further.

This has always been an interesting (an potentially quite useful) topic, but ** now ** we have an opportunity for some interesting posts, as Calliban and others work through the details of how a system might be deployed on Mars.

(th)

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#255 2023-09-01 10:32:26

kbd512
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Re: Trains on Mars - Could a rail system provide martian need

Calliban,

Air at sea level is around 1" of clear area around the conductor wire per 1,000V, but this is nearly a hard vacuum.

What "X-factor" does the dust add on Mars?

Can we make a cheap high-voltage / Iron-based conductor for a linear induction motor if we have permanent magnets?

I've been reading about linear induction motors recently, which is why that post piqued my interest.

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#256 2023-09-25 05:23:18

Mars_B4_Moon
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Posts: 9,774

Re: Trains on Mars - Could a rail system provide martian need

Once a system put in place for Mars it could need investment to keep all fictional and running smooth?

Joe Biden and Kamala Harris Admin fund projects

Biden administration announces $1.4 billion to improve rail safety and boost capacity in 35 states
https://apnews.com/article/biden-rail-s … 332a1ba146

fatal crowd crushes
management of people and a crush
crimes and safety?

With more people will come more chances of accidents, Kiss nightclub fire and crush in Brazil, the Hartford circus fire in the USA is an example of such disasters, crushes at islamic Arab events, crushes at Hindu festivals or ports and stations in India, the Stalin funeral crush, Soccer has such events Hillsborough disaster at a football event, Phnom Penh stampede in Cambodia.

Stabbing 'rampage' injures at least 12 in South Korea
https://www.bbc.co.uk/news/world-asia-66392177


Stampede in Seoul subway sparked by mass stabbing fear after man seen shoving people
https://www.independent.co.uk/asia/east … 15728.html
Police officials say suspect had medical history of mental health issues


People having a party and coming out of Covid, there was a sudden 'Seoul Halloween crowd crush'  159 people were killed and 196 others were injured. The death toll includes two people who died after the crush. The victims were mostly young adults; 27 of the victims were foreign nationals. The crowd crush is the deadliest disaster in South Korea since the sinking of MV Sewol in 2014 and the largest mass casualty event in Seoul since the Sampoong Department Store collapse in 1995
https://web.archive.org/web/20221030103 … 5161c8a4c4

Last edited by Mars_B4_Moon (2023-09-25 05:43:30)

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#257 2023-09-25 08:21:18

Mars_B4_Moon
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Re: Trains on Mars - Could a rail system provide martian need

They seem to have a Hyperloop of sorts working with a French commercial company and another company in China, Italy and France but for now it could be better to transport cargo first and not people?

the topics of building trains around Olympus Mons or Utopia Planetia, there might be maglve or monorail, perhaps a system high speed and stable tracks, very comfortable and powered by nuclear electricity, maybe  "Light rail" will not be a dirty word inside the communities, domes and tunnels of Mars?


Developing hyperloop technology across the world

https://www.globalrailwayreview.com/art … the-world/

China’s hyperloop project, which aims to develop ultra-fast land transport technology, has successfully completed its first test runs using a full-sized passenger capsule.

https://www.gizmochina.com/2023/01/19/c … nger-test/

'Toulouse Hyperloop: from Silicon Valley to Occitanie, how the project went off the rails'

https://westobserver.com/news/europe/to … the-rails/

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#258 2023-09-27 16:49:02

Mars_B4_Moon
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Posts: 9,774

Re: Trains on Mars - Could a rail system provide martian need

The Boring Company will IPO by 2028 and reach a $1 Trillion market cap by 2030.

It will have over 10,000 miles of tunnel by 2030, solving traffic problems in many cities and generating insane revenue. Its growth rate will still be rising.

By 2035 Boring will have over 100,000 miles of tunnel. By 2040 Boring tunnels will connect North America to Asia via the Bering Strait, replacing all cargo shipping and air travel across the Pacific.

"Prufrock is a next generation Tunnel Boring Machine designed to construct mega-infrastructure projects in a matter of weeks instead of years, and at a fraction of the cost.

The current iteration of Prufrock, called Prufrock-2, is designed to mine at up to 1 mile/week, meaning a tunnel the length of the Las Vegas strip (approximately 4 miles) can be completed in a month.

Prufrock-3 is designed to be even faster, with the medium term goal of 1/10 human walking speed, or 7 miles/day.

In the short term, if each Prufrock-2 mines at 1 mile/week, and TBC produces 1 new Prufrock machine per month, then TBC will be introducing 600 miles/year of capacity.

As a point of reference, less than 20 miles of underground subway tunnel has been constructed in the United States in the last 20 years."

https://twitter.com/elonmusk/status/1705180194925887847

By far the biggest impediment is getting permits. Construction is becoming practically illegal in North America and Europe!

And the measly incremental subway (or surface train) construction that has been done in recent years cost over $1B per mile!

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#259 2023-10-09 13:56:19

GW Johnson
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From: McGregor, Texas USA
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Posts: 5,618
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Re: Trains on Mars - Could a rail system provide martian need

I still do not understand why so many propose such expensive and construction-effort-intensive notions for surface transport on Mars!  Few-to-none can afford high-speed trains or hyperloops or any of that stuff here.  With the transport costs to Mars so high,  what makes you think it will be affordable on Mars?  That's utter nonsense!

Sit down and think this through.  For most (essentially all) cargo,  speed is NOT of the essence.  It just needs to get there,  eventually.  Same as here.  We spend too much on highway truck transport here,  when we ought to be shipping more by rail.  The problem is that rail was an expensive and effort-intensive infrastructure on Earth,  and it will likely be worse on Mars,  due to the interplanetary transport costs and the lethally-harsh conditions on Mars.

So,  what you want is surface transport with the characteristics of rail transport,  but not the high infrastructure-emplacement costs of rail as we know it here.  I briefly described such,  in post 252 above.

Creating a graded dirt road is easy,  way-easier than laying track.  On Mars,  you need not worry about rainwater drainage,  so the graded spoil embankments can remain alongside your smoothed surface.  We don't get to take that cheap approach on Earth,  but we can on Mars!  All you need is a big,  powerful road grader,  which can be a big tractor vehicle rather similar to the large ore carriers used in mining here.  The Martian one will need to be electric.  It can run on power from a small reactor,  either on a small trailer behind,  or via an extension cord from a stationary reactor.  Just mount a big blade on the thing,  and get to work!

Once the road is built,  take the blade off the tractor.  Take the driver out of the tractor,  and put self-driving software in charge.  This thing is quite powerful,  or it could not have graded the road.  Let it pull a whole string of trailers behind,  carrying cargo.  This is the basic freight train idea,  but without any tracks!  The software simply steers it between the spoil embankments,  until it reaches destination.  Put solar panels atop all the train cars,  and power the electric tractor that way.  Just move slow,  so the power demand is not too high for solar.   So what if it only moves in daylight?  Who cares?  So what if it only moves at walking speed?  Who cares?

Moving people point-to-point is different.  Time is an important consideration.  They need to fly,  somehow.

Lighter-than-air won't work,  whether done by hot-air methods,  or lifting-gas methods.  The density differences are so low at Martian atmosphere densities,  that the lift force you get will always be less than the Mars weight of any practical gas bag material.  Even in Hellas Basin:  twice next-to-nothing is still next-to-nothing.

Winged airplanes won't work,  because the densities are so low,  that despite 38% gee,  your landing speeds look like airliner cruise speeds here.  That will never work,  because the risk of a high-speed accident is so high that close to the surface,  during both takeoffs and landings. 

Helicopters scaled-up to carry people likely will not work on Mars,  because of low density effects far outweighing lower-gravity effects.  There is a square-cube law that limits what any aircraft (helicopter or fixed-wing) can do,  because materials are only so strong.  At small size,  drones can do things we have never been able to do with full-size helicopters here on Earth.  The situation is even worse on Mars.  Weight is reduced by factor near 3,  yes,  but density (and therefore aerodynamic forces,  is reduced by a factor of over 100. That utterly overwhelms you,  except in the very smallest sizes (Ingenuity is the tiny example,  and it just barely flies with no payload at all).

That leaves suborbital rocket travel.  At suborbital speeds,  there is not very much aerobraking available at journey's end,  so the landing dV will be comparable to the launch dV,  but I bet even their sum is less than the dV to low orbit,  even for a journey nearly halfway around the planet.  And little or no heat shield is required on Mars.  At least it is something to look closely at!  Plus,  here is a second reason to build propellant-manufacturing infrastructure on Mars.

GW

edit update 10-10-23:  I ran an orbit ellipse with periapsis inside the planet and apoapsis outside it,  such that it intercepted the surface on opposite sides of Mars.  That is the worst case for suborbital travel,  with the highest dV.  My hunch was wrong,  the speed needed to get onto this worst-case trajectory is actually comparable to the speed of low Mars orbit.  Something in the same class will be needed to land,  unless I can find a lot of aerobraking.  But the entry angle is steeper than from orbit,  sort of like an ICBM warhead on Earth.  We will see what I can dope out,  but this will take some time.

edit update 10-11-23:  I'm not at all sure I have the right orbit model,  so there is further work there.  I looked at the steeper entry with the orbit I had,  and found I could come out of the aerobraking hypersonics at about 5 km altitude,  if ballistic coefficient did not exceed 200 kg/sq.m.  That reduced the mission dV for the rocket,  but incurs serious heating,  serious deceleration gees,  and serious gees of last second rocket braking to land.  But the notion of a single stage reusable suborbital rocket "hopper" for journeys up to the antipodes does appear fundamentally feasible,  using prpellants made on Mars.

Last edited by GW Johnson (2023-10-11 08:48:03)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#260 2023-10-09 20:47:36

kbd512
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Posts: 7,612

Re: Trains on Mars - Could a rail system provide martian need

As GW suggested, if we can get the heavy equipment to Mars to create hard-pack trail roads, then we can use wheeled trucks, which is the best way to transport cargo if trains are impractical.  I think sand storms blowing fine abrasive dust around will make trains very difficult to run without unacceptable wear rates to the train wheels and tracks, even if there were no issues with creating railroad tracks and ties.  A MagLev train won't work since the dust is mostly Iron-oxide.  A compressed CO2 pipeline delivering plastic canisters is a more practical option for transport of heavy cargo over great distances, somewhat like a super-sized version of the system banks use for transporting paperwork to customers in their drive-thru.

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#261 2023-10-10 15:22:08

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,581

Re: Trains on Mars - Could a rail system provide martian need

Mars may be too cold for trains.  Ordinary low alloy carbon steels become increasingly brittle at temperatures beneath -20°C.  It is not uncommon for delivery trucks in Siberia to actually break their chassis.  At such low temperatures, steels need special alloying elements like manganese to remain sufficiently ductile.  This makes the steel more expensive.  It may be affordable for a vehicle chassis, but we would need huge quantities of steel to lay thousands of miles of rail track.  A Martian railway faces an additional problem - much greater diurnal and seasonal temperature swings than anywhere on Earth.  This raises the problem that rails will expand and contract a great deal.  This makes welded track impossible.  Rails would need to be laid in short sections, with an expansion gap between sections.  Those gaps cannot be allowed to fill up with dust.  How we could possibly prevent dust accumulation within those narrow slots between rail sections, I have no clue.  Maybe it could be blown out using a compressed air charge.

Would suborbital rockets not be too risky?  It used to be estimated that that the space shuttle had a 1 in 100 chance of suffering catastrophic failure.  This would make it 10,000 - 100,000 more dangerous than a jet flight.  Could we realistically make rocket vehicles safer by orders of magnitude?

Last edited by Calliban (2023-10-10 16:00:21)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#262 2023-10-12 18:02:59

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,581

Re: Trains on Mars - Could a rail system provide martian need

Previously, Terraformer has introduced the Ewing balanced monorail system.
https://en.m.wikipedia.org/wiki/Ewing_System

This could work on Mars.  One way of keeping energy costs to reasonable levels would be to produce a cast basalt plinth-rail, with a thin steel strip providing a cap that interfaces with the wheel.  The cast basalt rail would be pinned into a regolith road with barbed spikes.  The steel strip would be pinned onto the basalt plinth using steel pins that are cooled to cryogenic temperatures and subsequently expand providing an interference fit.

These ewing trains would operate at low speeds, but could carry heavy loads.
***********************************

Additional: Cast basalt has compressive strength of 300MPa and bending strength 30MPa.
http://www.abrasionresistantpipe.com/wp … -tiles.pdf

This makes it plenty strong enough to function as a rail, provided it is seated on a layer of settled stones and there are no unsupported spans greater than its thickness.  A layer of steel strip fixed to the top of the rail would spread load from wheels and prevent surface cracking.

Last edited by Calliban (2023-10-12 18:39:19)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#263 2023-10-16 17:28:03

tahanson43206
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Registered: 2018-04-27
Posts: 18,174

Re: Trains on Mars - Could a rail system provide martian need

This post is reserved for a study by GW Johnson on a "truck train" concept that could travel unattended for days on end on Mars.

I'm pretty sure other members have written posts that include these ideas, and I'd appreciate someone who might have a bit of time to look through the archive for them, and post links in a follow up post.

1) https://www.dropbox.com/scl/fi/e4hyc4u4 … 8ix95&dl=0

Pdf version of slide show

2) https://www.dropbox.com/scl/fi/1sn69zpa … c48fc&dl=0

Original PowerPoint version of slide show

3) https://www.dropbox.com/scl/fi/1v7ekdxy … pijox&dl=0

Additional thoughts on Surface Transportation ...

(th)

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#264 2023-10-17 14:31:31

kbd512
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Re: Trains on Mars - Could a rail system provide martian need

tahanson43206,

I don't see much utility in trains until there are enough people and known resources to make the infrastructure build-out worthwhile from an energy and cost perspective.  A combination nuclear and photovoltaic-powered crawler-transporter of some variety, seems to make a lot more sense.  If you had a large crawler with enough surface area on top to support enough photovoltaic panels, then you could have a kind of "mobile base".  A handful of small reactors would provide guaranteed life support while a large overhead PV array provides motive power when sufficient solar power exists.  Batteries can store the power, and then release it when you're ready to move.  It's a very heavy / slow moving vehicle, but it has functionally unlimited range, so long as there's no time-to-distance requirement.

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#265 2023-10-17 15:44:45

GW Johnson
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From: McGregor, Texas USA
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Posts: 5,618
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Re: Trains on Mars - Could a rail system provide martian need

Take a look at what I actually came up with,  by following the link.  It's a train without tracks. 

It'll make 11 or 12 km per day on solar power,  with an electric tractor revised from a mine loader vehicle.  The panels are on the freight wagons it pulls,  and I ran numbers for 10 to 100 freight wagons,  and on a 10% upgrade slope.  The friction is ~10 times that of tires on pavement. 

This thing is self-driving unmanned on a graded dirt road,  between berms of the grading spoil.  The same tractor fitted with a blade and a towing a shielded nuke generator trailer,  is the road grader,  which is fundamentally manned work,  and the only infrastructure to be emplaced. Dirt work there will be the same as dirt work here,  it's just that your tractor cab must be pressurized.

GW

Last edited by GW Johnson (2023-10-17 15:46:39)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#266 2023-11-25 18:06:39

Mars_B4_Moon
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Registered: 2006-03-23
Posts: 9,774

Re: Trains on Mars - Could a rail system provide martian need

Austria to invest €21bn into ÖBB rail network
https://www.railway-technology.com/news … l-network/

2020 article on the Lunar colonies?

Entire cities could fit inside the moon's monstrous lava tubes
https://www.livescience.com/lava-tubes- … table.html

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#267 2023-11-26 11:45:46

GW Johnson
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From: McGregor, Texas USA
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Posts: 5,618
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Re: Trains on Mars - Could a rail system provide martian need

Infrastructure emplacement on Mars is going to be a project idea killer for a long time to come.  It costs significant effort and money to do here,  with all the supporting industry and infrastructure available.  On Mars,  none of that support exists,  and the transport costs to Mars are going to be enormous,  even if Musk can make his Starship work as a transport to Mars.

Transport of time-insensitive bulk freight on Earth is best done by rail on land and ship on the water. We've known that for centuries.  There's no open water on Mars,  so time-insensitive bulk freight should go by train on Mars.  The problem is the track,  a very significant infrastructure emplacement,  there or here.  On Mars,  where would you get the steel rails?  It will be a very long time until there are steel-making facilities on Mars.  (It would be egregiously stupid to deny that.)  Plus,  what are you going to make the cross ties from,  when there is no wood on Mars,  and no Earthly concrete will work on Mars in that cold and near-vacuum?

What you need is a train without tracks.  That's a "truck train".

But you can't run it on a paved road on Mars,  because our Earthly concrete does not work there,  and neither is there any source of paving asphalt.  Nothing else is known but paving stones,  and that is horribly effort-intensive.  So,  you are looking at grading dirt roads on Mars,  and running your "truck trains" on those dirt roads.  With great big earth-mover-type tires,  which will need to be heated a little,  to avoid cracking in the cold.

There are but two practical ways to power these truck trains:  solar,  and mobile nuclear.  For solar,  you put the panels atop the freight wagons.  Speed is limited to that power which the panels can supply,  which means progress is slow.  Nuclear could be faster,  but requires the reactor be in a shielded freight wagon at the back of the train.  Make them self-driving. 

Time-sensitive stuff is going to have to fly.  There is no other way.  Same is true here.

GW

Last edited by GW Johnson (2023-11-26 11:57:40)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#268 2023-11-26 11:57:36

Void
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Registered: 2011-12-29
Posts: 7,395

Re: Trains on Mars - Could a rail system provide martian need

Australian Road Trains: https://en.wikipedia.org/wiki/Road_train
Quote:

Australia The term road train is used in Australia. In contrast with a more common semi-trailer towing one trailer or semi-trailer, the prime mover of a road train hauls two or more trailers or semi-trailers. Australia has the longest and heaviest road-legal road trains in the world, weighing up to 200 tonnes (197 long … See more

Image Quote: 600px-Aust_config2.png
Quote:

Road train types:
A: B-double
B: B-triple
C: A-double
D: AB-triple (possible BA)
E: BAB quad
F: ABB quad
G: A-triple
H: AAB quad (possible BAA)
K: Special Australian mining tipper road train with limited transportation

I only noted news about them because of your prior thinking expressed here.

Done

Last edited by Void (2023-11-26 12:00:24)


Done.

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#269 2023-11-26 12:57:29

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 3,581

Re: Trains on Mars - Could a rail system provide martian need

If the road train is carrying freight, it could be used to provide gamma shielding for a reactor.  The pilot car would need to be at the front of the train, with the reactor in the aft carriage.  Scattering from the surroundings could be a complication.  Provided the reactor is equipped with a neutron shield, it wouldn't be dangerous to approach it when it is subcritical or at very low power.  A reactor can be maintained critical at power level of less than 1 watt.  But people must remain in the leading carriage whilst the reactor is at power.  So all living space should be kept in the front carriage.

The road itself could be made from a layer of compacted fines atop a layer of more coarse rock.  We could make vehicles that would manufacture roads from the local regolith.  We would sieve the regolith, depositing coarse rocks first as a bed, then fines and then roll the fines to produce a compacted surface.

Last edited by Calliban (2023-11-26 13:08:30)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#270 2023-11-27 07:24:23

Mars_B4_Moon
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Posts: 9,774

Re: Trains on Mars - Could a rail system provide martian need

'Launch Loops'

https://www.youtube.com/watch?v=J1MAg0UAAHg

Some people talked of a rail to space launched on the high mountain peaks, Titan has Mountains known as Mithrim Montes is home to the hazy Saturnian moon's tallest peaks the mountain range, which has an elevation of 10,948 feet (3,337 meters) but Titan has a very thick atmosphere. Galilean moons are still being studied, Europa it seems doesn't seem to really have true Mountains like Earth but numerous isolated "massifs" the highest of these, located in the upper they are approximately 1,640 feet (500 meters) high. The solar system's tallest mountain most probably Olympus Mons, it rises three times higher than Earth's highest mountain, Mount Everest. The tallest mountain on the Moon is Mons Huygens, which is about 5,500 m (18,000 ft) high



UK rail freight still playing catch-up, warns Shoveller
https://www.railwaygazette.com/uk/uk-ra … 05.article
Britain's rail freight sector has work to do to catch up with road haulage in the race to digitalise its operations

Freight train accident costs the railroad three million euros
https://aussiedlerbote.de/en/freight-tr … n-euros-2/

Swedish railway companies take a hit after logistics company collapses
https://www.railjournal.com/freight/swe … collapses/

Freight train derails in Kentucky, governor declares state state of emergency
https://www.foxnews.com/us/freight-trai … -emergency

Last edited by Mars_B4_Moon (2023-11-27 07:34:46)

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#271 2024-03-21 17:12:26

SpaceNut
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Posts: 29,312

Re: Trains on Mars - Could a rail system provide martian need

Branching Aerospace firm Northrop Grumman, which will be designing the system US unveils wild plan to build a train network on the Moon

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#272 2024-03-22 10:25:59

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 5,618
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Re: Trains on Mars - Could a rail system provide martian need

There's a tradeoff you must consciously make,  selecting between road trains and rail trains.  Rail trains have far lower rolling friction coefficients,  meaning it takes much less power to propel them.  But unless you carefully design AND MAINTAIN the track and its roadbed,  you will suffer derailments!  And poor track maintenance also lowers max speeds,  as the prime means to try to prevent derailments.  That up-front design and construction effort,  plus the ongoing maintenance,  is expensive.  But the energy cost to move cargo is very low indeed.

Road trains require a lot more power to move,  and will be inherently slower,  because of higher rolling friction and a much rougher surface on which to roll.  But there is very little maintenance to do,  unless you invest in hard pavement,  and even then it is less than maintaining a proper railroad track.  Most of the difficult design issues have more to do with water drainage and wet soils,  something non-existent on Mars.  Cheaper up front,  cheaper to maintain,  particularly if using only graded dirt roads.  But you pay a lot more in terms of the energy to move cargo this way.

Paving the road adds speed and lowers cost to move cargo,  but requires much higher up-front cost,  and incurs more ongoing maintenance costs.

As I said,  it's a tradeoff.

GW

Last edited by GW Johnson (2024-03-22 10:29:44)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#273 2024-03-23 17:58:25

JoshNH4H
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From: Pullman, WA
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Re: Trains on Mars - Could a rail system provide martian need

As much as I love trains, it's not clear to me that any kind of lunar train network will pencil for the foreseeable future. What kinds of goods will even be shipped, and in what quantities, and over what distance? It's a bit hard to say.

But for starters, there will be spaceports at least some distance from each base, iron mines, aluminum mines, silicon mines, water mines, carbon mines, nitrogen mines (though water, carbon, and nitrogen will all likely come from permanently shadowed craters they may not come from the same permanently shadowed craters).

On Earth the case for rail over road is that the rails give you better fuel economy, longer-lived equipment, and the ability to use less labor to ship more stuff. But building a rail line costs money—more than a road, despite having a narrower use case—so it doesn't pencil unless there's high volume (coal and oil are often shipped by train, along with other stuff) or someone's already built the rail line.

On the moon I think the driving factor towards something like a railroad is different: Electric power.

I don't want to get into a big argument over power sources, but in my view solar photovoltaics are the path of least resistance for the Moon if you can make them work.  The biggest challenge there is the two-week long lunar night, which would mean very large storage requirements.

But there is another way: Since bases will be clustered around the South Pole, you can build a grid that circumnavigates the pole with solar sites spaced at, say, 120 degrees. At near-polar latitude the panels will cast long shadows, meaning your array will use a lot of land, but the moon has as much land as all of South America and I don't think this is a big deal. You can also build your power stations significantly north and run lines down to the base locations. China has power lines that go 3200km (diameter of the Moon is 3400km) and they're not at the physical limit, meanwhile the low gravity, stable environment, and vacuum make it even easier to build power lines on the Moon.

There is a point to this digression, which is that we should expect the Moon to have a pretty well-built out power network early on. This ends up being pretty important for the idea of long range transport, because burning hydrocarbons is a waste of hydrogen and carbon unless you recapture, which comes with difficulties, nuclear is poorly suited to the size of transport, batteries are inconveniently heavy—especially if you want really good ones brought from Earth, etc.  The most logical way to build out a transportation network is to piggyback on your electricity transmission network.

So what you end up with is roads—paved in the busiest corridors (with what I'm not sure, possibly just sintered) or cleared and leveled elsewhere, under an electrical catenary which provides power to the vehicles running underneath it.

I asked Bing's AI image generator to make this, just to see what I could get. Didn't capture everything I'd want (had a tough time getting it to put Earth in the sky) but it's a cool look anyway:

GJZRtY1WIAAOBan?format=jpg&name=medium

On Mars though? Plain old combustion engines in trucks, in all likelihood. Possibly bigger trucks. Oxidizer is a tougher question than fuel. Pressurized oxygen is probably the easiest thing. Electrified routes probably come later.

Last edited by JoshNH4H (2024-03-24 07:35:01)


-Josh

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#274 2024-03-24 17:44:59

Void
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Registered: 2011-12-29
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Re: Trains on Mars - Could a rail system provide martian need

JoshNH4H,

No one else answered you, so I will.  I think your analysis is correct.  But anybody having any interest in doing anything on the Moon seems good news to me, so I like the train story anyway.

Done

Last edited by Void (2024-03-24 17:47:08)


Done.

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#275 2024-03-25 08:41:30

JoshNH4H
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From: Pullman, WA
Registered: 2007-07-15
Posts: 2,559
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Re: Trains on Mars - Could a rail system provide martian need

I looked into this a bit because I would certainly apply to the Moon Train team if there was such a team.

The grant was issued as part of the 10-Year Lunar Architecture (LunA-10) capability study which issues grants not to exceed $1,000,000 each. Pocket change for a MIC.

Cool though and I hope the results are public


-Josh

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