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I've been playing a lot of Deserts of Kharak lately, and I am wondering if landships depicted in game, which are essentially seagoing ships on tracks, would work in a Snowball Earth scenario. By Snowball Earth, I am using the classic Snowball Earth scenario, where all of the oceans are frozen, and the equatorial regions have temperatures of around modern-day Antarctica.

So would landships be a preferred method of transporting bulk cargo from one place to another in a snowball earth, say, compared to airlift? What challenges might a landship that runs on tracks or wheels might face on the glaciers other than structural issues of building such a titanic vehicle in the first place?

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  • $\begingroup$ glaciers are incredibly treacherous to cross, full of crevasse, icefalls, and snow bridges (chasms hidden by a layer of snow), made even worse by the unpredictability and constantly changing terrain. Even on foot they have a high risk, regularly trying it in a fast moving or heavy vehicle is just expensive suicide. Go around the glaciers. $\endgroup$
    – John
    Jul 8 '17 at 4:59
  • $\begingroup$ I had a similar question. Not exact but should give you an idea: worldbuilding.stackexchange.com/questions/36860/… $\endgroup$
    – Marky
    Jul 8 '17 at 6:01
  • $\begingroup$ @John Not really. en.wikipedia.org/wiki/South_Pole_Traverse is routinely traversed with heavy equipment and supplies. In fact this road was built (for lack of better word) specifically to make resupplying Amundsen-Scott base easier. Other regions routinely use en.wikipedia.org/wiki/Ice_road - frozen lakes as roads in winters. Using large tracked vehicle with pressure spread out over large area isn't as dangerous as you describe. $\endgroup$
    – M i ech
    Jul 8 '17 at 13:02
  • $\begingroup$ First ice roads are very very different than glacier roads, and the south pole traverse was laid out to avoid terrestrial glaciers whenever possible, requires constant maintenance to map, level, and fill in crevasses, and it still has lost entire cargo "trains" into crevasses. $\endgroup$
    – John
    Jul 8 '17 at 14:13
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I am not familiar with Deserts of Kharak, so I had to look up what their landships looked like... and I must say, those do not look like "ships" to me. They look like very big trucks or tanks. So if you're willing to call all of the things "ships" that that game chooses to identify as "ships", then sure. Just call whatever your preferred land-based mode of transportation is a "landship", and "landships" will be the preferred mode of transportation, by default. It is a trick of language, and nothing more.

So, I'm going to split the rest of this answer into two parts: what are the challenges associated with massive ground vehicles on a snowball Earth, and what would actual ship designed to run on ice and snow be like?

As far as massive tracked vehicles go, you'll note that powered vehicles designed specifically for travelling on ice and snow in the real world already use tracks! Some of them also use skis (i.e., snowmobiles), which are much better than tracks or wheels for unpowered support elements, but always tracks for the motive force. This is for two reasons: 1) ice and snow are slippery, and you need tracks to get enough grip (the same reason you can use skis for non-powered support); 2) ice and snow don't support as much weight as rock and dirt, so you need to spread out the weight of your vehicle over a larger area. So the tracks are a pretty good feature, and the challenges faced by a gigantic, aircraft-carrier size multitrack vehicle will be largely the same as those faced by present-day snowmobiles: distributing their weight over a large enough surface area to avoid sinking into the ground, and maintaining traction (although solving the first problem takes care of the second pretty much for free).

Tracked vehicles do have some unique problems that get worse with size, however, and are at odds with the need for traction on snow and ice: in particular, they skid when they turn. The simplest way to deal with this is to make the vehicle much wider than it is long, but that is not always practical. Another, more flexible option is to segment the vehicle, like a train, and/or complicate the track mounts to allow individual track sections to rotate independently for steering. Realistically, however, even with both strategies employed, these things are going to have very large turning radii, even compared to their enormous size. In that sense, they are rather like actual ocean-going aircraft carriers!

As for actual ship-like things, snowships have a big advantage over, e.g., sand sailers, in that snow, as previously noted, is slippery! That means you can get away with having a primary hull in direct contact with the round, stabilized by outrigger skis, and it's plausible that wind could still propel them. If sailing still proves impractical, however, snowships could propel themselves with snow screws, analogous to the screws / propellers of ocean-going ships. Unlike the propellers of an ocean ship, however, the propulsion screws of a noon-sailing snowship would also provide direction support and balance, taking the place of outrigger skis. On very large ships, however, a continuous line of screws from bow to stern would initially seem to present similar problems in turning as tracks do, although that could be ameliorated by simply have the screws at the back and support the front of the ship on skis, more like a traditional water-going ship. However, screws have some distinct advantages over treads, in that if you rotate both screws in a pair in the same direction.... you move sideways! I.e., these ships can strafe, which a tracked vehicle cannot do, and while turning around curves still involves some amount of skidding, a screw-driven snowship of arbitrary size with bow-to-stern screws could easily rotate in place with little or no skidding, which a tracked vehicle cannot do.

If sail-powered, rather than screw-powered, snowships can be made to work, then they might well be a major method of transporting bulk cargo. But, while a whole lot of cargo is moved around our world by trucking and oceanic shipping, and those options are cheaper and can carry larger loads than air transport, tracked or screw-driven vehicles are at a major disadvantage compared to contemporary trucks and ships: without power, they stop moving. A truck on wheels can roll for a good long ways while idling, and a ship can coast on inertia for a long while before hydrodynamic drag stops it. In either case, the engines need to provide far less power to maintain speed than they do to get up to speed. With tracked or screw-driven vehicles, this is not the case, and they are far less efficient. It thus seems far more likely that bulk cargo transport would be accomplished with trains, hovercraft, or perhaps even aircraft. Aerostatic craft (i.e., cargo zeppelins) may even be a quite reasonable option.

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  • $\begingroup$ Nice one with the screws and their features! I've completely forgotten about screw propelled vehicles. $\endgroup$ Jul 8 '17 at 6:14
  • $\begingroup$ I enjoyed your thoughtful and informative answer. Loved the idea of screw-propelled snowships turning in circles or sliding sideways. Plus one. $\endgroup$
    – a4android
    Jul 8 '17 at 7:00
  • $\begingroup$ Alternatively, you could use propellers like hovercraft do for propulsion. $\endgroup$ Jul 8 '17 at 9:05
  • $\begingroup$ Strafing land-based carrier/factory, mental image right out computer game, and yet, according to your answer, oddly realistic. I would upvote your answer just for this image alone. $\endgroup$
    – M i ech
    Jul 8 '17 at 13:07
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Air lifting is very expensive when transporting resources across a planet. If you wan't any kind of serious trade between different locations on the planet, land travel is essential. In our world, trains are used for transporting heavy goods such as coal or grain. A world like this would need a complex rail system for trade to be practical.

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