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GW did answer better than I could.
[i]"I promise not to exclude from consideration any idea based on its source, but to consider ideas across schools and heritages in order to find the ones that best suit the current situation."[/i] (Alistair Cockburn, Oath of Non-Allegiance)
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Actually, I think rail gets built fairly early on Mars - at least just around the main base to start. Some other thoughts...
Railroads, I think, would mostly be a problem because of steel consumption. Construction of a railroad would actually be cheaper and faster per mile, in terms of work, than on Earth.
* You don't need traditional ballast, at least until you start warming Mars up. Just use water - the ice would be fantastically hard and strong under Mars conditions, and you could melt the top to a very fine level. Sink the concrete ties in it and attach the rails
* in the low gravity, bridging and viaducts would be simpler to build than on Earth, as well.
* Steel wheels are easier than rubber wheels on Mars.
An option which might be profitably discussed would be an ice plateway - a flattened ice road with two grooves for steel wheels, rather than two rails. While this would have severe issues in terms of maximum speed, we're not terribly concerned with maximum speed, are we? And such roads would be fairly inexpensive to build, and could be upgraded to rail as steel production allowed.
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Actually, I think rail gets built fairly early on Mars - at least just around the main base to start. Some other thoughts...
Railroads, I think, would mostly be a problem because of steel consumption. Construction of a railroad would actually be cheaper and faster per mile, in terms of work, than on Earth.
* You don't need traditional ballast, at least until you start warming Mars up. Just use water - the ice would be fantastically hard and strong under Mars conditions, and you could melt the top to a very fine level. Sink the concrete ties in it and attach the rails
* in the low gravity, bridging and viaducts would be simpler to build than on Earth, as well.
* Steel wheels are easier than rubber wheels on Mars.
An option which might be profitably discussed would be an ice plateway - a flattened ice road with two grooves for steel wheels, rather than two rails. While this would have severe issues in terms of maximum speed, we're not terribly concerned with maximum speed, are we? And such roads would be fairly inexpensive to build, and could be upgraded to rail as steel production allowed.
Why do people build railways on Earth? Because (a) they need to move thousands upon thousands of tonnes to serve millions of people (b) because the terrain - with bogs, and rivers, mountains and so on, are not well suited to roads and road traffic and (c) because rail can go faster than road.
Neither of those drivers will apply on Mars in the early decades. (a) The early communities will only need a few tonnes of this and that per month (b) the terrain - certainly in the areas where we will site the first bases - will be firm and well suited to road traffic once the rocks and boulders are removed and (c) we won't have the technology in place to build bullet trains on Mars - the gain in speed will be minimal, possibly non-existent.
Incidentally,we can use steel wire wheels on Mars.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Hi Louis:
I think your assessment in the last post is just about right.
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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Hi Louis:
I think your assessment in the last post is just about right.
GW
Glad you agree. I have nothing against developing rail. I am sure it will come and might be used in a limited way in mining areas. But I think road traffic will just be the obvious choice for the first few decades. We should remember as well we aren't necessarily talking about manned individual cars and trucks. There could be convoys of driverless road vehicles navigating either by Mars GPS satellite, or transponders laid out at the road side, or by computer controlled recognition of white lines (or perhaps a combination of all three).
I can see such convoys happily trundling from a mining area to a central base at a steady 20 kms per hour over boulder-cleared roads (tracks really, since there won't be any road building as such).
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Louis:
I would guess that by the time there are people staying more-or-less "permanently" on Mars, we'll have added GPS capability to the satellites in orbit around Mars, the same way we did here. You could use pretty much the same equipment.
If not, the first "truck" transports will have to be driven over graded roads by humans. But once Mars GPS is in place, you could do a simple set of pre-programmed GPS waypoints along the road, and have very simply-automated "trucks" drive point-to-point.
Later, as the local colony grows, you could reduce the energy consumed in "truck" transport by around a factor of 10, by going to rail transport. This makes sense when the shipments are bigger, and enough infrastructure is in place to make the steel. I suspect ties there will have to be steel as well, at least at first, since no practical concrete we know sets in that cold. I also suspect that a good concrete-equivalent will be developed.
It's a bootstrap process, just like it was here.
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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Maybe in the early years the focus could be on developing long range railroads. The advantages are enourmous.
1.large masses could be transported with a modicum of energy.
2.reliable. The techology used in railroads has been on earth for 180 yrs, enough time to work out most of the bugs!
3.adaptable. it does not take much effort to lay a railroad bed (although if a mining oparation occured, there would be a need for substaintal reinforcement of beds) and almost any source of energy could be used to propel the train. .the tracks do not limit the type of train (except electric) on the tracks!
4.Cheap. I'll grant the initial cost might seem a bit on the high side, but the tracks will last for 20-30 yrs of continuous use. Don't forget martain gravity is less, making wear and tear less, too. less wear and tear means less replacement, making it cheaper to run.5.verstile. Anysort of cargo can be moved, including large, heavy and bulky pieces. (mining, again, would most likly involve modification of track bed.
6.fast. It would be quicker than dune buggys for sure, never having to stop or slow down on the track.
I like this idea. Maybe a maglev/vacuum train? that's cool....
Or even just a regular train would be fast and simple to construct, and easy to run, perhaps powered with solar power.
Trains are proven to be reliable transportation in the harshest of conditions - i.e. Siberia, Alaska and Svalbard have train lines. A train can run on a variety of energy sources.
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fixed shiting issue on page 1 & 2
The rail once layed takes away all the obsticals that a rover has to go slow to avoid just look at the MSL;s wheels....
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If an internal combustion engine is possible on Mars, then a locomotive hybrid with gas turbine electrical transmission and fuel cells could be possible. At the beginning and major stops of multi-days or months of a railway trip, the fuel cells are recharged and gas tanks refueled. Major infrastructure would have been built -- not economical before human population in settlements will have been large.
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An old idea of steam locomotive could be revive on Mars. Can the Boudouard reaction of carbon monoxide exergonic convertion to carbon dioxide and carbon can be used for driving engine ? At the beginning, the locomotive stores pressurized carbon monoxide which was made using geothermal, nuclear or solar enegy and shipped from local power plant. When the train is running, due to low Martian temperature, the exergonic reaction from CO to CO2 is favored. The heated CO2 exhaust under pressure exhaust is the energy source for locomotive. The carbon byproduct removed at next train station and CO is refueled. The carbon is collected and returned to power plant to regenerate CO using Martian atmospheric CO2.
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An old idea of steam locomotive could be revive on Mars. Can the Boudouard reaction of carbon monoxide exergonic convertion to carbon dioxide and carbon can be used for driving engine ? At the beginning, the locomotive stores pressurized carbon monoxide which was made using geothermal, nuclear or solar enegy and shipped from local power plant. When the train is running, due to low Martian temperature, the exergonic reaction from CO to CO2 is favored. The heated CO2 exhaust under pressure exhaust is the energy source for locomotive. The carbon byproduct removed at next train station and CO is refueled. The carbon is collected and returned to power plant to regenerate CO using Martian atmospheric CO2.
Why not use stored carbon and liquid O2 as fuel? Or for that matter, liquid methane and liquid O2? As a rule, you want the highest energy density possible between refuellings. Another option might be banks of those super lightweight solar panels that Louis was talking about, feeding energy directly into a third rail. That way, your vehicle carries no fuel and is lighter and you have no conversion losses. With so little atmosphere and no moisture, losses will be low.
Last edited by Antius (2016-05-22 12:10:21)
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It may be a very good idea to cover the tracks with some kind of lightweight tenting, to keep out any dust that may otherwise cover the tracks. If you do that, then you might as well make the top from solar panels (complete with windscreeen wiper to keep off any dust, of course). At least some of the time, it's unlikely to require most of the track to produce sufficient power.
Use what is abundant and build to last
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Yes the continuous PV panels are a good idea - not unlike the "electric roads" idea, if you know about that.
knightdepaix wrote:An old idea of steam locomotive could be revive on Mars. Can the Boudouard reaction of carbon monoxide exergonic convertion to carbon dioxide and carbon can be used for driving engine ? At the beginning, the locomotive stores pressurized carbon monoxide which was made using geothermal, nuclear or solar enegy and shipped from local power plant. When the train is running, due to low Martian temperature, the exergonic reaction from CO to CO2 is favored. The heated CO2 exhaust under pressure exhaust is the energy source for locomotive. The carbon byproduct removed at next train station and CO is refueled. The carbon is collected and returned to power plant to regenerate CO using Martian atmospheric CO2.
Why not use stored carbon and liquid O2 as fuel? Or for that matter, liquid methane and liquid O2? As a rule, you want the highest energy density possible between refuellings. Another option might be banks of those super lightweight solar panels that Louis was talking about, feeding energy directly into a third rail. That way, your vehicle carries no fuel and is lighter and you have no conversion losses. With so little atmosphere and no moisture, losses will be low.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Why not use stored carbon and liquid O2 as fuel? Or for that matter, liquid methane and liquid O2? As a rule, you want the highest energy density possible between refuellings. Another option might be banks of those super lightweight solar panels that Louis was talking about, feeding energy directly into a third rail. That way, your vehicle carries no fuel and is lighter and you have no conversion losses. With so little atmosphere and no moisture, losses will be low.
Do you mean a some kind of levitation ? How about quantum locking by superconductors that push the whole freight train up. Then with Louis' talk on using electric power from solar panels, its propulsion on wheels is the only force resulted from pushing backward on the ground.
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This is just a guess, but I think any sort of rail tracks on Mars will need enclosing against the dust. There is the potential for the tracks to get buried. Same sort of thing happens to desert railways here.
If you go rail with real tracks, electrify them from a power plant and use electric locomotives. If there is a way to effectively plow the drifted dust, then so much the better. But it had better not short out your electrified tracks. Putting the power line overhead gets it out of the dust, but adds a lot more structures to build.
Most of those design decisions depend upon ground truth and experience we yet do not have about Mars. That's why I think rail will get built later, not earlier.
If you can power the vehicle, a truck can pull a train of trailers on a simple graded road. I think that's how bulk transport on Mars will get started. My guess for the power is fuel cell electric augmented by solar PV panels atop the truck and all the trailers.
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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So we would need to power down the tracks when the slides occur and then send a debri sweeper that gets powered by another method down the tracks to clear it before repowering up. I would see lots of cameras on this to aid in the tele robotic clearing.
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If you do rail transport on Mars in the manner that we do it here, there's the rails, and there's the ties, and there's the roadbed.
You don't lay track on unprepared ground (I know they did for the transcontinental railroad, but it didn't last). Roadbed is appropriately-graded gravel mix of the correct stone shapes, and it must be available in truly mass quantities. Without it you bend or break your tracks. This is not something you just scrape up with a bulldozer.
Ties here are most often wooden, but on the faster lines, can be cast reinforced concrete. We would need a concrete substitute on Mars, in mass quantities, to make the ties. And we need steel for its reinforcing. About the only other useful material strong enough to do the job as a tie would be steel itself.
The rails are not plain low-carbon steel. They are a low-carbon alloy steel using some other metals that confer enormous strength and resilience. Plain carbon steel wears out way too quickly, and is far too easily destroyed in a derail incident.
There's a lot of manufacturing infrastructure needed to support building such a thing on Mars.
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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If you do rail transport on Mars in the manner that we do it here, there's the rails, and there's the ties, and there's the roadbed.
You don't lay track on unprepared ground (I know they did for the transcontinental railroad, but it didn't last). Roadbed is appropriately-graded gravel mix of the correct stone shapes, and it must be available in truly mass quantities. Without it you bend or break your tracks. This is not something you just scrape up with a bulldozer.
Ties here are most often wooden, but on the faster lines, can be cast reinforced concrete. We would need a concrete substitute on Mars, in mass quantities, to make the ties. And we need steel for its reinforcing. About the only other useful material strong enough to do the job as a tie would be steel itself.
The rails are not plain low-carbon steel. They are a low-carbon alloy steel using some other metals that confer enormous strength and resilience. Plain carbon steel wears out way too quickly, and is far too easily destroyed in a derail incident.
There's a lot of manufacturing infrastructure needed to support building such a thing on Mars.
GW
Plain carbon steel rails would undergo brittle fracture in Mars temperatures. You would need to find a lot of alloying elements to make the steel usable- eg Manganese and Nickel.
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Like I said, even here, rails are not plain carbon steel. Most of the tougher alloys we use here are brittle in Siberian cold. The 300-series stainless alloys are good to cryogenic temperatures, but they aren't very tough, not for use as railroad rail.
We'd have to select the right alloy to get get toughness at cold temperatures, for sure. I don't know one right off the top of my head. But maybe one or two of the heat-treatable stainless alloys like D6 or 4130 might work. That would be something to research.
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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I wonder if canals would be a good idea, if sufficient water is available? You don't need to contain that much pressure to keep them liquid (and the dust out!).
Use what is abundant and build to last
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Assuming we do this near 0 C liquid water temperatures, and assuming a humid atmosphere is maybe 3% by volume water vapor, we need 6 mbar water vapor partial pressure to keep the liquid stable. At 3% of total, the atmosphere pressure inside the cover over the canal is near 200 mbar.
If you fill that cover over the canal with pure oxygen, 200 mbar is plenty for unassisted breathing without any sort of mask or suit. It is pure oxygen, so there's problems with long-term exposure, and with a horrific fire hazard. But it might be habitable.
That is an entertaining notion: humans putting canals on Mars. I suppose we could even have draft animals pulling the canal boats, generating fertilizer, for farming along the banks of the canal inside the pressurized space. Not a short term prospect, but something to think about.
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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Actuallly, I was thinking more of a 50% partial pressure. The covering is just to keep it from evaporating away, and of course to keep the dust out.
Use what is abundant and build to last
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Actuallly, I was thinking more of a 50% partial pressure. The covering is just to keep it from evaporating away, and of course to keep the dust out.
A slight variation on the idea: a seam welded carbon-steel pipeline, pressurised to 200mbar with atmospheric CO2, filled to 50% height with brine and covered with regolith to a depth of 1m to eliminate thermal stresses due to temperature variations. That eliminates evaporation and with no free oxygen, there can be no corrosion. As soon as a Mars colony is capable of mass producing plate steel, this becomes a possibility. Maybe polypropylene or concrete pipes would do the job just as well.
Pipelines could be useful for transporting bulk liquids as well. Liquid CO2 from polar regions could be piped to gas-cooled nuclear reactors or solar thermal plants closer to the equator, which would then boil the CO2 into a high pressure gas and release it through a gas turbine. The resulting power plant could be remarkably compact and without the need for a recompression cycle, quite efficient even at low peak temperatures. Water and air are other precious commodities that we would have interest in transporting about. Produce them at the poles using a nuclear reactor and transport them to colonies anywhere on the planet by pipe. Minerals could be transported as finely ground slurry. Without the obstacles presented by rivers, lakes and oceans, a Martian civilisation could literally grid the planet with pipelines.
Last edited by Antius (2016-07-19 17:16:12)
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Ah means to an end for getting materials and people to and from cities and resources on mars.
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Can carbon nanotube be useful? Less carbon nanotube material than ferromaterial is used in electromagnet for Maglev?
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