New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: As a reader of NewMars forum, we have opportunities for you to assist with technical discussions in several initiatives underway. NewMars needs volunteers with appropriate education, skills, talent, motivation and generosity of spirit as a highly valued member. Write to newmarsmember * gmail.com to tell us about your ability's to help contribute to NewMars and become a registered member.

#201 2020-08-14 04:47:07

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 10,397

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

Re kbd512 #200

SearchTerm:CompareWheelvsTrackVehicles

http://newmars.com/forums/viewtopic.php … 83#p171083

(th)

Offline

#202 2020-08-14 16:06:16

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 1,895

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

It will be a real ball ache if it proves impossible to use plain carbon and low alloy steels on Mars.  There is no way we could afford to make railway tracks out of austenitic stainless steel.  Non-ferous alloys are either too soft (aluminium or copper alloys) or too expensive (titanium).

Maglev would get round the problem.  Or maybe conventional rail built in shallow subsurface ducts that are covered in sand to avoid thermal cycles.  A high speed hovercraft using some sort of ram scoop might be able to travel across Mars without a track.  A solid core nuclear thermal rocket could provide the necessary propulsion.


"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."

Offline

#203 2020-08-14 16:34:24

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 25,674

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

i believe that changes were made to the 2020 persaverence rover based from curiosity cracked and missing pieces.

Offline

#204 2020-08-14 16:55:07

SeaDragon
Banned
From: Merry Old England
Registered: 2020-07-25
Posts: 32

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

kbd512,

I think I follow now. Summarising in arguments from first principles:

- Ground clearance advantages aren't possible for wheeled vehicles anyway since larger wheels are all but impossible for humans to replace on site so tracked systems, while more complicated, can be constructed from smaller parts for the same ground pressure and lifting ability.

- Speed and range advantages for wheels aren't seen in rough terrain and in practice only work when you have smooth roads over which to move at least for the analysis provided for the Stryker. Being fair though a single bad design isn't a counterargument to a larger classification of machines: just because the F-35 sucks doesn't mean propellers are better for air superiority fighters than jet engines. Opinion seems more positive about the Boxer AFV for example, not to mention lighter systems like the Toyota Land Cruiser which are highly popular in the desert.

- Many smaller wheels is likely better for electric motors which are naturally predisposed to high speed low torque and need gears to get to low speed high torque, hence a tracked system can be made more suitable and less demanding of its motors. This is only amplified if we're making our own and have to use less than ideal substitutes for Earth-based tech:  aluminium over copper, AlNiCo over neodymium. Combined with better grip I can see this weighing less in practice than wheels.

I'm still a bit iffy regarding sand/dust/regolith getting stuck between treads and how to lubricate tracks (bearing in mind everything needs to operate at near vacuum getting good lubrication isn't nearly so cheap or easy as on Earth) but otherwise I see your points and will probably go with tracks in future.

Side note, regarding US defence funding decisions, I kind of get it: if you make cheap, reliable and excellent weapons they might well end up being used against you. If you're the only force on Earth capable of getting an F-35 to fly, the enemy running off with blueprints for this machine doesn't help them very much! When laser technology matures and that colossal air intake makes it the only fighter capable of providing the shaft power necessary to run one suddenly the entire equation changes and you have a very powerful weapon that's too advanced for anyone else to copy (though as of today this plane is just garbage imo). Add in to that the extra US employment associated with such complicated logistics and you have a good argument for a deliberately inefficient defence industry. Of course, Martian transport cannot possibly operate under such a structure.

Last edited by SeaDragon (2020-08-14 16:59:17)

Offline

#205 2020-08-14 21:04:40

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,693

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

If they used that much harder Aluminum alloy mixed with nano particles of Alumina Oxide that I posted about, even Aluminum wheels would wear like iron.  It's so hard that you have to use carbide or PCD coated tooling to machine it.

Offline

#206 2020-08-15 00:51:29

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,693

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

SeaDragon,

With respect to tracks vs wheels, that's the big and small of it.  Yes, there's more parts.  However, the parts are small chunks of forged steel that take the vehicle they're attached to many tens of thousands of kilometers over rough terrain before replacement or refurbishment is required.  Each track link has a single pin or bolt, a pair of nuts to secure the pin through two track links, and three bushings to reduce friction between the pin and connected track segments.  The track links are adjusted or replaced by hand using hand tools.  You do need a large ratcheting wrench to bring the final two links together to pin them and a torque wrench to secure the nuts properly, but those are simple hand tools that don't require cranes or jacks or motors or hydraulics or electronics.  A come-along (a steel or kevlar rope) is used to roll the track over the drive sprocket and road wheels.

A track will exert less ground pressure than a handful of large wheels, not the same or more ground pressure.  An 8 wheeled vehicle may have a contact patch of 8 square feet.  The T157 track links are 21 inches wide.  Multiply that by about 15 feet or so.  The difference in ground contact surface area is huge (630ft^2 vs 8ft^2).  Of course ground pressure is lower for the tracked vehicle.  How could it not be if both vehicles are the same tonnage?  That's critical for going over sand or mud or loose gravel-type material and not sinking into the ground.  Moreover, you get a lot more traction as well (all that ground contact surface area) and have a lower CG to boot (less chance of rollover).  Traction is also why wheeled vehicles can be faster and more fuel efficient on roads.

Wheels don't provide as much traction (contact surface area with the ground), so they have less rolling resistance at higher speeds over smooth paved surfaces (rubber band tracks are a close competitor to rubber wheels, however, because they also have less rolling resistance than steel track links), so they go faster using less fuel as a result.  The super singles on semis actually produce less rolling resistance than dualies, despite having more contact patch with the ground than the dualies, because of how the wheel is designed and how much it flexes (or doesn't) as the wheel passes under the axle.  That'd also be why truckers prefer using dualies in snow or rain or off-road.

Ever notice how the off-road speeds listed for both heavy wheeled and tracked combat vehicles is 40kph to 50kph?  Think there might be a reason for that?  If you go any faster with either type of vehicle, you're pretty much asking to break something.  There's a limit to everything.  Go too fast with too much weight over soft ground and the probability of an accident becomes too great to ignore, hence the use of governors for off-road operations.  It doesn't matter how fast you can go if you don't make it to your destination in one piece.

With respect to dust and grit, the M113s performed far better than the Strykers over the abrasive volcanic sands in Afghanistan.  Mars is covered with volcanic sands.  There isn't any special grease or other petroleum-based lubricant on the track.  It uses polymer bushings and polished bearing surfaces.

Edit:
I removed my response on the F-35 weapon system and reposted it here:

What Does "A Better Design" Actually Mean?

Last edited by kbd512 (2020-08-15 01:21:24)

Offline

#207 2020-08-16 15:37:21

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,833
Website

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

Depends upon how rough the roadway is,  for the choice of wheels versus tracks.  That in turn depends upon how good a job you do bulldozing a roadway out of primitive surface.  Your bulldozer probably needs tracks.  Your truck-train probably does not,  if you do a good-enough job bulldozing the roadway. 

GW


GW Johnson
McGregor,  Texas

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

Offline

#208 2020-08-21 20:04:08

kbd512
Administrator
Registered: 2015-01-02
Posts: 5,693

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

GW,

If there was some way to ensure that the roadway was sufficiently "hard-packed", then I'd tend to agree that wheels would be better than tracks.  If that's not feasible, or if the roadway is six feet of sand with the large rocks removed, then tracks are going to do a better job than wheels.  If there was a practical way to build lengthy roads on Mars, then of course I'd favor using wheeled trucks.  The problem is starting from absolutely zero infrastructure, due to lack of usable local resources and the infeasibility of importing them, to a fully self-sustaining miniature spin-off of human civilization.  I think you'd agree that that's a pretty tall order.

Offline

#209 2020-08-21 21:00:20

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 10,397

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

For anyone working this topic ...

Historically, it is my understanding we (humans) have ** always ** used two rails for railroad tracks.

I know that monorails exist in a few locations, such as amusement parks.  I asked Google about monorails:

1820
The first monorail prototype was made in Russia in 1820 by Ivan Elmanov. Attempts at creating monorail alternatives to conventional railways have been made since the early part of the 19th century. The Centennial Monorail was featured at the Centennial Exposition in Philadelphia in 1876.

Monorail - Wikipedia
en.

The first date of 1820, and the country (Russia) were a surprise but not a surprise.  Russia has had smart and innovative citizens in every era I've read about.

I bring this up because while using two rails is ** very ** traditional, it is ** not ** necessary, and the Russian example shows that the concept could be applied on Mars.   The amount of metal required for the rail could be reduced by laying it on top of a bed of bricks made from Martian regolith. 

(th)

Offline

#210 2020-08-21 21:17:04

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,833
Website

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

The rails in a monorail take loads in three-dimensions of very significant magnitude.  A two-rail system takes significant loads only in 2-D on a curve,  and essentially 1-D on a straight run.  Two-rail track can be laid on ties bedded in gravel.  A monorail cannot.  Not by a long shot.

GW


GW Johnson
McGregor,  Texas

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

Offline

#211 2020-08-22 00:00:54

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 10,397

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

For GW Johnson re #210

Your observations inspired me to investigate a bit further.

https://ggwash.org/view/67201/why-citie … -explained

The article above goes into some detail explaining the pro's and con's of monorails, which are in use in a few cities on Earth in 2020.

The author makes clear why the con's outweigh the pro's in situations which predominate in most transit situations.

Apparently monorails do well in situations where elevated movement is needed.

The reason I brought up the possibility of monorails for Mars was the difficulties others have listed in earlier posts in this topic.

I am skeptical of the practicality of laying traditional iron rails on wooden crossties on the deep sandy regolith of Mars.

Seadragon had proposed frozen regolith pylons a while back.  I've been keeping that interesting idea in mind, and am now imagining a waist high monorail track made of frozen regolith, with a thin metal overlay just thick enough to protect the frozen material from wheels rolling over it.

The issue of loading in various dimensions seems to me to be addressable, by judicious use of banking, if banking makes sense with frozen regolith.

(th)

Offline

#212 2020-08-22 05:57:49

Terraformer
Member
From: Ceres
Registered: 2007-08-27
Posts: 3,525
Website

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

GW,

A monorail doesn't have to be 3D?

The Ewing Syste uses a single rail to take the load and a balancing wheel to steady it.

Perhaps a better option for Mars than conventional rail.


"I'm gonna die surrounded by the biggest idiots in the galaxy." - If this forum was a Mars Colony

Offline

#213 2020-08-22 08:43:15

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 10,397

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

For Terraformer re #212

I am looking forward to looking at the link you provided, when I am using a computer that can pull it up. 

It's good to see your support for the (to me) practical alternative of a monorail design for Mars.

So far (as I am recalling the options) we have roads, no-road overland, two rail railroads, Seadragon's suspended cable concept (and derivatives), pipelines with or without water for floating barges and even (I'm stretching for this one) ice roads, which would permit sledge operation thanks to the low co-efficient of friction as solid turns to liquid under pressure and then returns to solid after the vehicle passes.

A monorail build on Seadragon's frozen regolith seems like a reasonable possibility for Mars, due to its consistently low surface temperatures.

Edit#1: A monorail made of frozen regolith covered with a "rail" of ice would be a possible extension of the idea.

Speed of travel on such a system could be fairly brisk, I would think.

(th)

Last edited by tahanson43206 (2020-08-22 08:45:37)

Offline

#214 2020-08-22 10:55:01

GW Johnson
Member
From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,833
Website

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

Your rails will see lots of bending loads,  whether two-rail or monorail.  Bending means one side sees compression while the other side sees tension.  Tension?  Ice has NO tensile strength,  just great compressive strength,  much like unreinforced concrete. 

That's why you see monorails overhead that use reinforced concrete pillars supported steel rail. It's also why two rail systems get away with wooden crossties supporting steel rails.  As long as the crossties are properly supported by embedding deeply into crushed stone "gravel". 

In Japan,  they got away from the wooden-crossties-rotting-as-they-age problem,  and from the gravel support problem which requires frequent repacking,  by going to reinforced concrete crossties.  It's an up-front higher capital cost,  but you save with far lower maintenance costs over the long haul.  All they do is replace worn rails for the approximately-50-year life of the reinforced concrete ties.

I like the idea of frozen regolith as the equivalent of gravel-supported crossties on Mars.  But,  they WILL require reinforcement be embedded within,  to take the tension portion of the bending loads.  You can't just freeze what's there,  you will have to sift and grade the rocks to work properly as the aggregate around the rebar-equivalent,  within the ice-and-sand matrix.

There is a problem with exposed frozen anything on Mars:  sublimation.  Plus,  in the summer at lower latitudes,  temperatures can get above freezing.  Somehow,  you have to coat frozen structures to avoid sublimation,  and shade them from solar energy when the air temperature is above freezing on Mars.

GW

Last edited by GW Johnson (2020-08-22 10:58:34)


GW Johnson
McGregor,  Texas

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

Offline

#215 2020-08-23 07:18:17

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 10,397

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

For GW Johnson re #214

Good point about sublimation of ice in the Mars environment << sigh >>

However!  You did provide some encouragement for the basic idea from Seadragon, of building pylons of frozen regolith. 

My adaptation of that idea is to consider a low conical shaped "road" for wheeled vehicles. with Martian bricks set to bear the wheel loads of vehicles passing overhead.

The success of any idea or set of ideas (with respect to the competition) will come as a meld of all the costs(investments of time, thought, energy) and benefits of the approach.

Trying to make do with an over-the-sand movement with tracks (per kbd512) or wheels (NASA) is the most basic stage.

A gently graded lightly packed sand road seems a reasonable extrapolation for a passage that is well traveled.

At the next stage, where a well traveled path is worth investment, there are a number of candidate approaches planners might consider.

It may turn out that it is simpler and more universal to just make a flat road out of Seadragon's frozen regolith, supplemented by a layer of Martian brick.

Such a road could be navigated by wheeled or tracked vehicles.

The conical cross section of the "monorail" concept has a potential advantage that it will shed sand more readily than would a flat road, so in that respect would require less maintenance during the dust season.

Otherwise, on the disadvantage side, it would require cars and a locomotive with undercarriage shaped to fit over the mound.

On the advantage side, it ** might ** consume less time, material and energy to build a system using this configuration, than would be required for a traditional flat road, or a flat "rail" road made of bricks set on cross-ties made of frozen regolith.

Your example from Japan brought that last concept to mind.

Edit#1: This topic provides a foundation for input by an experienced civil engineer.

The competing roadway alternatives explored in this topic can be analyzed in detail for:

Costs (time, thought, energy)
Benefits (Speed, reliability, load capacity, maintainability)

(th)

Last edited by tahanson43206 (2020-08-23 07:31:12)

Offline

#216 2020-08-23 10:10:56

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 10,397

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

This is a bit of a stretch from the topic title "Trains on Mars" but I'm hoping it can be tweaked enough to fit ...

https://www.airspacemag.com/multimedia/ … 180951234/

The mats described in this article were (and apparently still are) made of steel.  They had holes to allow water to pass through, and interlocking tabs to facilitate assembly by (sturdy) workers with mallets.

Something like that might work on Mars, where both iron and aluminum are available, albeit with some expenditure of effort (time, thought, energy).

A steel mat roadway would definitely serve tracked vehicles well, and it would be better for wheeled vehicles than native sand covered terrain.

Since sand storms would cover the roadway over the course of a Martian year, the iron could be located by sensors if some magnetic properties are planned for in the creation of the alloy to be used.

(th)

Offline

#217 2020-08-23 10:17:08

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 25,674

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

I have seem floors of wood bricks for the same reason to solve for the seasonal water changes. Mining iron ore is easy for mars its the energy required to process it to the finished form that is the problem especially early on in mission transition to cities from those early crew exploratory missions.

Offline

#218 2020-11-23 10:49:13

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 25,674

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

Seems we will be more ready for use of trains on mars as we push away from fossil fuels here on earth.
Hydrogen-powered trains could replace diesel engines in Germany

Siemens and Germany's rail operator Deutsche Bahn have announced plans to test a hydrogen-powered train with a range of more than 370 miles, technology that promises to reduce CO2 emissions and help make 1,300 diesel units obsolete.

The new hydrogen drive will save around 330 tons of CO2 a year, the companies said.

This could also go in another topic as well..

Offline

#219 2022-06-02 08:41:26

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 2,578

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

Unless people figure out how to make people and animals walk and bring stuff on Mars and Ride Bicycles the Trains of Mars might be most efficient form of goods, passenger, material transport. Maybe they will be above ground so people can view 'The Sights' of Mars?

Germany Slashes Summer Train Fares More Than 90 Percent to Curb Driving, Save Fuel
https://e360.yale.edu/digest/germany-sl … -save-fuel

Physical Transportation on the Moon: The Lunar Railroad
https://ascelibrary.org/doi/10.1061/40339(206)41
'The rail network can be constructed from indigenous materials by tele-operated robots at the lunar base. As the railroad grows outward from the lunar base, it will provide transportation for its own growth and for other construction projects such as the lunar electric power grid and telecommunications network.'

Offline

#220 2022-06-02 21:28:54

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 25,674

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

It would seem to fit with the underground cities that we will live in once there

Offline

#221 2022-06-09 10:32:04

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 2,578

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

Hyperloop: Fast, But At What Cost?
https://hackaday.com/2020/12/09/hyperlo … what-cost/

some previous discussions


Hyperloop, Earth/Mars
https://newmars.com/forums/viewtopic.php?id=7571
'Land propulsion - Tracks, or tires?'
https://newmars.com/forums/viewtopic.php?id=3511
Infrastructure
https://newmars.com/forums/viewtopic.php?id=10077
'Roads on Mars'
https://newmars.com/forums/viewtopic.php?id=3511
How do you build a physical economy?
https://newmars.com/forums/viewtopic.php?id=5677
Tunnel Transportation on Earth, Mars or Luna
https://newmars.com/forums/viewtopic.php?id=9843
Combustion engines ... - ... on Titan and Mars
https://newmars.com/forums/viewtopic.php?id=3515

Offline

#222 2022-06-17 10:06:23

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 2,578

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

Interns Lead the Way in DARPA Robotics Challenge and Find Their Futures
https://www.jpl.nasa.gov/edu/news/2022/ … r-futures/
'projects including a snake-like robot designed to explore deep crevasses'

NASA reveals mission to explore mysterious Gruithuisen Domes on Moon
https://news.yahoo.com/nasa-reveals-mis … 00208.html

While NASA is finding ways to use 3D printing technology to provide necessities for colonising Mars, Union Pacific (UP) is applying the same technology to make locomotive operations safer and more efficient.
https://railway-news.com/union-pacific- … ilroading/


Perhaps an entire Mars railway station could be 3-D printed before the colonist arrive? Need stairs, small market shops and streets, a hospital facility, a manufacturing hub, statues and artwork of people, eagles, past explorer and past leader and animals, canteen and restaurant, a railway station.... maybe in the future AI and Robots will have arrived on Mars to already have everything 3-D printed.

3D Printed Trains
https://www.gambody.com/blog/20-promine … ay-models/
Modern engineering companies start to collaborate with 3D printing technology firms to produce some interior parts on 3D printers. This can include grab handles, armrests, seat-back tables and other components. The technologies are quickly developing, and this brings more opportunities to the business.
Big corporations are in search of more ways of employing 3D printing technologies to benefit from them. And you can 3D print a locomotive, rail station, speed train and other sets along with railways at home using high-quality STL files of impressive 3D models. Each fantastic replica of a classic, old and contemporary train station and rails figures leads your way toward crafting and mastering 3D printing on your own.

Perhaps 3-D print your Mars cars

or your visual entertainment a nd aesthetics

Marquette 3D models, Disney and MArvel and DC and pop stars
https://www.cgtrader.com/3d-print-models/marquette
Here you can find Marquette 3D models ready for 3D printing.

3D Printing Without Support
https://hackaday.com/2014/11/30/3d-prin … t-support/
3D printing is getting better every year, a tale told by dozens of Makerbot Cupcakes nailed to the wall in hackerspaces the world over. What was once thought impossible – insane bridging, high levels of repeatability, and extremely well-tuned machines – are now the norm. We’re still printing with supports, and until powder printers make it to garages, we’ll be stuck with that. There’s more than one way to skin a cat, though. It is possible to print complex 3D objects without supports. How? With pre-printed supports, of course.
[Markus] wanted to print the latest comet we’ve landed on, 67P/Churyumov–Gerasimenko. This is a difficult model for any 3D printer: there are two oversized lobes connected by a thin strand of comet. There isn’t a flat space, either, and cutting the model in half and gluing the two printed sides together is certainly not cool enough.

Offline

Board footer

Powered by FluxBB