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#1 2025-11-10 19:12:43
- tahanson43206
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Suspension Bridge Martian City Roof Design
This post is inspired by a vision of Calliban for open air cityscapes that look like Amsterdam.
This vision depends upon the presence of a roof so far above the street level that LED lighting systems can create a plausible simulation of Earthly blue sky and clouds moving slowly across the scene.
This topic is available for NewMars members who might wish to add link, images or text about how this concept might be implemented on Mars, and how life in such an environment might look, sound and feel.
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#2 2025-11-10 19:13:33
- tahanson43206
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Re: Suspension Bridge Martian City Roof Design
This post is reserved for an index to posts that may be contributed by NewMars members.
Index:
Post #3: Image of the longest suspension bridge on Earth.
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#3 2025-11-10 19:17:12
- tahanson43206
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Re: Suspension Bridge Martian City Roof Design
This post shows a suspension bridge between Europe and Asia at Turkey.
The central span is over a mile long (2 kilometers). That is on Earth! The same span would be easier to achieve on Mars.
A requirement is for the roof to be overlaid with regolith to counter 1/2 bar atmospheric pressure inside the habitat, and to provide radiation protection.
The underside of the roof would be fitted with LED lighting systems to simulate blue sky and clouds moving as they might appear on Earth.
Such a roof could easily simulate the dark sky scene, with every sun, planet, galaxy and other visible object.
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#4 Yesterday 17:59:45
- Calliban
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Re: Suspension Bridge Martian City Roof Design
For Calliban re new Suspended Roof topic...
https://newmars.com/forums/viewtopic.php?id=11235
Of all our members, it seems to me you may be best qualified to add substance to this new topic.
I am hoping your previous work on cast iron would extend to this structure.
It seems likely you would need stronger material for the cables, and that would require energy, but a city like this is going to happen only if there is sufficient energy available to splurge on metalurgy. Assuming you have enough energy, am i correct in thinking a city scape using suspended roofing with regolith cover for pressure balance and radiation protection would make sense?
The alternative is to dig underground, and it seems to me that unless huge natural cavities are found, it would ** always ** take more energy for excavation than would be required for the suspended roof concept.
(th)
One material that we have examined in the past is cast basalt. This has compressive strength of 300-500MPa. This is about the same as the tensile strength of low alloy steel. From the data in the attached article, I estimate that between 1.5-2MJ of heat are needed to transform 1kg basalt from a room temperature solid to a castable liquid. Basalt has density 3t/m3, whereas low alloy steel is 7.8t/m3.
http://www.rmag.soil.msu.ru/articles/478.pdf
Low alloy steel has an energy cost of about 30MJ/kg if produced from ore rather than recycled metal. On Mars, it will all be produced from ore for a long time to come. This means that 1 cubic metre of cast basalt has about 2.5% of the energy cost of the equivelant volume of steel. We also need a lot less equipment to produce cast basalt. An electrically heated furnace and a set of moulds to cast the ceramic members.
Cast basalt tiles could then be glued together using a thin film of epoxy resin to produce a tibrel vaulted roof. If the tiles are polished after casting, then the epoxy film could be as thin as 0.1mm thick. The vault would then be covered in a thick berm of compressed graded regolith.
Last edited by Calliban (Yesterday 18:26:50)
"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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#5 Yesterday 18:35:13
- tahanson43206
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Re: Suspension Bridge Martian City Roof Design
For Calliban re cast basalt as a building material. In the context of a Suspended Roof system for Mars (as distinct from a roof that depends upon support from below such as a tibrel vaulted roof), would cast basalt have the strength needed to support suspension cables.
This topic is designed and intended to provide a venue for development of designs using suspension to hold a roof against Mars gravity. We have a topic in Architecture where the idea of a tibrel vaulted roof might be developed.
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