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For SpaceNut ...
I am looking forward to seeing how this topic develops over coming Sols ... The idea of making a tunnel only 1 meter in diameter caught me by surprise. Is there an example of such a tunnel having been bored horizontally on Earth? Vertical bores that size would not be surprising (to me at least), but ....
Oh! Perhaps the (relatively new) technology of bending the path of a bore allows for horizontal runs of that size.
In "real world on Earth" practice, bending bores are quite common for routing of new gas lines in residential neighborhoods. Perhaps extension of that technology to Mars situations would turn out to be practical and cost effective.
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In past topics in NewMars forum, members have discussed manufacture of bricks from regolith. I would imagine such bricks could be manufactured for use as tunnel liners. In that role the bricks would be taking compression loads as the regolith above the tunnel descends/ compresses vertically.
(th)
The issue for mars has more to do with the equipment needed to produce the desired diameter tube with regards to delivered mass and energy needs to make it work on mars.
A 1 meter diameter tube still can act as a crawl connection. with Of course a 2 meter tube is a walk in the park and large is where we can get serious about other uses..
The other part of the issue for materials is the mass that is supported on its surface to ground as there is limited ability to shore up from within as a mine shaft would do. Adding a grid re-enforcement on the outside like the iso grid pattern using extra materials like that which is use in the space capsule design would give the tube more load baring weight.
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I think the small tube of 1 or 2 meters could be done with partial covering via trenching method as proposed by Loius in other topics in that digging should be kept to a minimum for creating these types of connecting solutions in the early days of mars growth.
The tunnel bricks would need to be shaped and interlocking linner so as to keep them in place before the tube were inserted to create a sealed pathway for man, fluid, gas or for electrical to pass through.
Maybe google or others will chime in on the 1 meter diameter question for practicle or not size and use.
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High Density Polyethylene can be used for making pipes for power distribution, sewage or drainage. Ethylene can be made from hydrogen reduction of carbon dioxide.
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Burried in the ground not issues with UV once installed, temperatures would be moderated but would be effected by how cold the content of the pipe is and the pressure needed to keep it in liquid form. Only room temperature and up are indicated in the articles for thus far.
https://en.wikipedia.org/wiki/High-density_polyethylene
https://www.creativemechanisms.com/blog … ng-and-cnc
Numbered types of plastics
https://sciencing.com/hdpe-plastic-5839257.html
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A Preliminary Assessment of the Initial Compression Power Requirement in CO2 Pipeline “Carbon Capture and Storage (CCS) Technologies”
https://res.mdpi.com/technologies/techn … tachment=1
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For SpaceNut re #105 ...
Interesting paper! Thanks!
The work done here seems (to me at least) pertinent to the Mars environment, but NOT (of course) because of combustion of fossil fuels. I can imagine there might be a need to ship compressed atmosphere from one location to another via pipeline.
I cannot think of a reason why this would be useful on Mars for long distances, but on the other hand, if a separation plant were to be constructed to isolate Oxygen (for example), then shipment of compressed CO2 over short distances inside the facility might make sense.
(th)
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A novel idea. For this to really be workable, we would need to mine the southern polar cap and use a heat source to melt the dry ice at a pressure of several bar and temperature of about -50C. This would allow the CO2 to be pumped. Maybe geothermal power could be used as the heat source. If we were clever, we could use CO2 phase change to power the mining equipment.
A pipeline 1m in diameter, with flowrate of 10m/s could carry thousands of MW of power. Liquid CO2 would be pumped to cities closer to the equator, where solar heat would be used to generate high pressure CO2 to power gas turbines for electricity production or to generate direct mechanical power, such as for compressed air tools or mining equipment.
The absence of intervening seas and oceans allows for the development of global grids on Mars, transporting power using CO2, as well as electricity; and water harvested from ice deposits and pumped to cities thousands of km away. It is also possible to transport physical goods and raw materials by pipeline, by encasing them within floating hydraulic capsules in either brine solution or liquid CO2. Kind of like an enclosed canal network.
Of course, pipelines represent a significant investment in infrastructure. A pipeline from the southern cap to the equator would require tens of thousands of tonnes of steel or plastic. Not something that would be done until significant settlements existed on Mars.
"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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Calliban to further your delight in topics that are related.
Compressed gas energy storage.
Hopefully that will get you thinking some more...
You may like this front page Journal article as well Mars Air and Water might be the key to power storage
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Testing of such analog functions here on earth for the Mars society stations seems a perfect fit for insitu creation. Both primary and secondary goals need this.
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Moved from http://newmars.com/forums/viewtopic.php?id=307
Interesting thread. On Earth, large diameter pipelines are one of the most energy efficient ways of moving bulk commodities. On Mars, it is easy to imagine a global network of cast basalt pipes transporting air, liquid CO2 and water, to cities on every part of the planet. Could we use pipelines to transport solid goods also?
In principle there's no reason why you couldn't have canals inside insulated pipes, with the interior being heated above zero celsius by PV panels or other energy systems on the surface. The canals could be used for transport of goods by narrow boats.
I would query though why we would go to that expense.
Pipeline transfer of liquid CO2 and water sounds more likely, though probably not for the first few decades. For the first few decades I think the emphasis will be on road transport of essentials, because the population levels won't justify pipeline construction. Remember also that the likelihood is that the Mars settlement will have very efficient forms of water recycling, minimising the need for importation of water into the settlement.
Calliban wrote:Interesting thread. On Earth, large diameter pipelines are one of the most energy efficient ways of moving bulk commodities. On Mars, it is easy to imagine a global network of cast basalt pipes transporting air, liquid CO2 and water, to cities on every part of the planet. Could we use pipelines to transport solid goods also?
Not something we would do in the early days of Mars settlement I don't think. This sort of infrastructure makes sense if you need to ship a lot of raw materials and/or freight from one place to another. If you are operating a mine for example, that is producing 20million tonnes of iron ore each year and you want to ship it to a city with a big steel works 1000km away, then a 1m diameter pipeline, carrying floating capsules at 2m/s, will get the job done at a very low energy cost per tonne/km. It wouldn't make sense trying to heat the water. Rather, we would put some sort of antifreeze (salt) into it and bury it under a few feet of soil to protect it from temperature fluctuations.
When serious colonisation of Mars begins and millions of people move there, we will find there is a mismatch between where we concentrate industrial capacity and people and where the raw materials are. To make steel, we would need iron ore, electricity and a reducing agent (methane) would be useful, if Mars has any. To a certain extent, we would try and move production to where the most logistically difficult resource is. But either way, some resources will need to be transported. Finished steel may be needed at some other city, maybe on the other side of the planet. Without any seas or oceans to get in the way, we can transport materials anywhere on the planet using roads, railways, pipelines, etc. Pipelines are simply an energy efficient, though slow way of doing this.
"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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For transport of goods, I had 'floated' the idea of water pipes containing capsules carried along by the flow, rather like a modern canal system using a continuous stream of barges. One weakness of this idea is it's relatively slow speed. To keep friction low and avoid excessive energy costs, water speed must be no greater than a few metres per second. That means that a 1m diameter pipeline could deliver at most 1tonne/second of freight.
A train moving freight at 50km/h, with a gauge of 1m, could deliver freight 10 times more quickly. Then again, there would need to be gaps between trains for safety and railways must be constructed from steel and sit on a compacted bed capable of withstanding dynamic loadings. It would be interesting to know which option would be better in terms of delivered freight for invested cost.
Pipelines only make sense if you are prepared to wait quite a while for the goods to arrive. At a velocity of 2m/s, it would take 58 days to transport a capsule from side of Mars to another. A railway system could do the same job in week. The energy costs would be greater, but still quite small. Would it be easier to lay a pipeline than a railway?
"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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I've always been a fan of road transport on Mars. As far as I can see, if you choose your routes carefully, the roads on Mars are ready-made, a bit like the ice roads of North America. Clear the boulders, put down some markers and off you go...
On Mars, as in Australia, we could have road trains:
https://www.youtube.com/watch?v=0iFkKRh5kcM
One 250 ton vehicle can transport by road a quarter of a million tons of ore per year. Maybe carrying something like 700 tons of ore on one load ...not sure exactly.
When you consider the expense involved in building and running railroads - ensuring the rails and sleepers are in good order etc. - I think the road alternative makes good sense, certainly while the population remains under 100,000.
For transport of goods, I had 'floated' the idea of water pipes containing capsules carried along by the flow, rather like a modern canal system using a continuous stream of barges. One weakness of this idea is it's relatively slow speed. To keep friction low and avoid excessive energy costs, water speed must be no greater than a few metres per second. That means that a 1m diameter pipeline could deliver at most 1tonne/second of freight.
A train moving freight at 50km/h, with a gauge of 1m, could deliver freight 10 times more quickly. Then again, there would need to be gaps between trains for safety and railways must be constructed from steel and sit on a compacted bed capable of withstanding dynamic loadings. It would be interesting to know which option would be better in terms of delivered freight for invested cost.
Pipelines only make sense if you are prepared to wait quite a while for the goods to arrive. At a velocity of 2m/s, it would take 58 days to transport a capsule from side of Mars to another. A railway system could do the same job in week. The energy costs would be greater, but still quite small. Would it be easier to lay a pipeline than a railway?
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Ice road truckers on Mars. I like it. The truck could drive during the early morning and late afternoon and roll out a flexible PV array to recharge in the midday sun. I think that would work well. Without any roads or competing traffic, there is a lot of flexibility when it comes to the size and shape of such a vehicle.
"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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Plot 0039 plot 0040 and plot 0008 for inclusion of concept for My Hacienda On Mars elements to business growth.
Drop arrays and battreries along the path and you can make it back to home base by following the bread crumbs. The dropped stations are for fast recharge as they will be active all the time for storing energy once deployed. This is how we extend the range for all mobile exploration missions. Now to figure out if these few posts plus a few more can be the start to a new topic....or just a benchmark in the My Hacienda On Mars topic under the mobile survey exploration plot.
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How expensive would the canals be to construct? Particularly with salt water, the pressure doesn't need to be more than say 20mb. Could we use prefabricated sections, dropped into a trench with regolith bulldozed over the top? Would they have to be circular cross sections, or could we get away with an ellipse, giving us quite a flat and wide bottom?
A 5m wide, 20m long, 1m deep barge would carry 100 tonnes of cargo. If it moves at 3m/s, it can cover 10km every hour.
Use what is abundant and build to last
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Yes, that's pretty much my thinking. Probably just single rover trucks to begin with but likely becoming more like road trains over the years. The rover trucks or road trains can be robot vehicles guided by GPS and roadside transponders. Might make more sense to have solar power stations along the way, so that the vehicles can immediately start charging up, so they aren't delayed for too long. You'd probably need humans to journey up and down the road trails inspecting the road, maintaining the way stations and clearing sand or anything else that accumulates on the trail.
Ice road truckers on Mars. I like it. The truck could drive during the early morning and late afternoon and roll out a flexible PV array to recharge in the midday sun. I think that would work well. Without any roads or competing traffic, there is a lot of flexibility when it comes to the size and shape of such a vehicle.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Probably cheaper than a railroad I would think if looked at over say a 30 year period as maintenance would likely be fairly minimal. As long as you are not leaking you're good! As long as humans aren't required to navigate it, that should keep costs right down. Heating the water is probably not that expensive if the pipes are well insulated.
How expensive would the canals be to construct? Particularly with salt water, the pressure doesn't need to be more than say 20mb. Could we use prefabricated sections, dropped into a trench with regolith bulldozed over the top? Would they have to be circular cross sections, or could we get away with an ellipse, giving us quite a flat and wide bottom?
A 5m wide, 20m long, 1m deep barge would carry 100 tonnes of cargo. If it moves at 3m/s, it can cover 10km every hour.
Last edited by louis (2020-02-10 14:30:31)
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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For hydraulic capsule pipelines, cast basalt pipes would be both strong and wear resistant and can be cast in iron moulds. With perchlorate antifreeze, water will remain liquid even at -60C. Vapour pressure at such low temperature is negligible. A few feet of soil cover should be enough to protect the pipe from temperature swings. The pipes could be slotted together and glued.
"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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Excellent point about anti-freeze...what percentage of the water has to be the anti-freeze substance? When you say perchlorate, is that as per what is found on the surface of Mars?
For hydraulic capsule pipelines, cast basalt pipes would be both strong and wear resistant and can be cast in iron moulds. With perchlorate antifreeze, water will remain liquid even at -60C. Vapour pressure at such low temperature is negligible. A few feet of soil cover should be enough to protect the pipe from temperature swings. The pipes could be slotted together and glued.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Excellent point about anti-freeze...what percentage of the water has to be the anti-freeze substance? When you say perchlorate, is that as per what is found on the surface of Mars?
Calliban wrote:For hydraulic capsule pipelines, cast basalt pipes would be both strong and wear resistant and can be cast in iron moulds. With perchlorate antifreeze, water will remain liquid even at -60C. Vapour pressure at such low temperature is negligible. A few feet of soil cover should be enough to protect the pipe from temperature swings. The pipes could be slotted together and glued.
Last time I looked into this, there appeared to be far more data available that wasn't behind paywalls. Calcium chloride solution (30% weight) reduces freezing point to -42C.
https://www.engineeringtoolbox.com/calc … _1186.html
But it does bad things to viscosity. Water with that much CaCl2 in it, has 20 times the viscosity of pure water at 20C. Sort of like syrup. That raises the obvious problem of much higher pumping power needed, unless speed is reduced even more. Unless an antifreeze can be found that depresses freezing point to Mars ambient without pushing viscosity too high; the concept of hydraulic pipeline capsule transport looks a lot less attractive.
"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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For everyone contributing to this topic ...
Why use liquid at all?
Transports would move a LOT faster if they were sleds with runners on ice.
I'm not sure if it is practical for Mars, but it seems reasonable (to me at least) to suppose that ice tunnel pipes would work fine for high speed transport through the (remaining) glaciers of Antarctica.
To my knowledge, there's been little need for such a transportation system in Antarctica, but if there WERE a need, it shouldn't take too long for an energetic contractor to excavate ice from a trench, install a roof of some kind, and replace the excavated material over the trench.
(th)
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The are chlorites but not much in the way of calcium...
So is the canal an open faced trench under the plastic that is stretched and hung over its length or is the over sized pipe partially filled with water solution to which the transport system floats down its path. I would think that the top 3rd of the over sized pipeline would be clear while the other portion can be normal. Hopefully the mass of the water solution could hold the waterway from float due to air pressure such that we would not need to do such heavy anchoring as a surface greenhouse would need. The clear portion would be coated to filter UV and might even have some water tubes to lower the radiation that might get through.
actually there is no need for water at all as the tunnel can be made from basalt or other cast materials to create it. This would amount to a subway for mars for that configuration due to size. One could walk, scotter ect...from location to location under protection and no space suit.
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Wouldn't regular passing of sled blades melt the ice? Sleds only work well when they are isolated vehicles, or perhaps a few vehicles, passing over the same spot. If you had 100s passing over the same spot in one sol, then I suspect you'd get melting of the ice, blades would experience increased friction as they dug into the ice and you'd have a problem on your hands...
For everyone contributing to this topic ...
Why use liquid at all?
Transports would move a LOT faster if they were sleds with runners on ice.
I'm not sure if it is practical for Mars, but it seems reasonable (to me at least) to suppose that ice tunnel pipes would work fine for high speed transport through the (remaining) glaciers of Antarctica.
To my knowledge, there's been little need for such a transportation system in Antarctica, but if there WERE a need, it shouldn't take too long for an energetic contractor to excavate ice from a trench, install a roof of some kind, and replace the excavated material over the trench.
(th)
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Allow solar heating via heat exchanger panels on the surface and allow fish to swim in the water as in fresh and salty for ocean water and grow food in these tunnels that have light coming in through the top part of them. Solar reflect more light and line the area inside to reflect it about inside.
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