Brief scenario: Evil Genius (EG) with a lot of money and lots of loyal henchman wants to take over the world by mass-producing vast quantities 2-3ft tall spider robots (SR).

The plan would begin with the EG distributing around a thousand shipping containers around the globe that contain machinery that can 1) outfit another shipping container with a copy of itself and 2) Can outfit another shipping container to become a mini-factory for producing the SR units.

The battle for world domination would begin by securing raw materials needed for SR production, and cranking up production so that targets could be overwhelmed by tens/hundreds of thousands of SR units.

Ultimately, the EG needs to make the production sites safe have a secure source of power to keep the manufacturing going. This requires a believable power source that could be packed into a shipping container but still crank out enough power to melt down any available steel for use in SR production.

Essentially, I'm trying to close the plot hole as to why authorities can't simply blackout the power grid to stop new SR units from being produced to stop the invasion. Plus, it would give the ability to manufacture SR units in places that don't have power grids.

What would be believable tech for shipping container-sized power generators that could be produced en masse without being detected prior to the trap being sprung? (This probably rules out miniature nuclear reactors, since they would be detected before they could get distributed around the world.) Ideally, it should be able to run >3 weeks with fuel initially contained in the shipping container.

FWIW: A standard 20′ shipping container can hold 1,170 cubic feet and the max gross weight is 30T

  • $\begingroup$ When? If this is a do it today question the answers are very different to those that are possible with a little future tech, or a lot of it. $\endgroup$ – Ash Aug 8 '18 at 18:16
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    $\begingroup$ If your container-based factory can recreate a copy of itself, why can't it build as many generators (solar, wind etc.) as it needs? $\endgroup$ – Alexander Aug 8 '18 at 18:18
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    $\begingroup$ THere's an inconistency here. If your shipping containers outfit a second shipping container to produce SRs, they have to split the available fuel and wasted fuel outfitting it instead of building SRs. Perhaps it would make more sense to answer the question from the perspective of a single container that only makes SRs, and does not waste any energy making factories? $\endgroup$ – Cort Ammon Aug 8 '18 at 18:23
  • $\begingroup$ Hamster power is a broadly underrated source of short-term energy. $\endgroup$ – boxcartenant Aug 8 '18 at 18:31

Ant power

Okay, not really powering this by ants, but powering it using the same methodology ants use.

You will find all answers to your question end in "don't." You don't want to store the energy with you. Unless you are interested in nuclear power (which you have stated you aren't), energy densities are in the 40 to 100 MJ/L range for reasonable fuels. Most are around the 40MJ/L range, like gasoline which weighs in at 34MJ/L.

A shipping container full of gasoline has an amazing amount of energy. But the task you strive to do requires a lot of energy too. I did some handwavy calculations with lots of fudge factors, and it would surprise me if you could process more than a few tens of tons of steel using ultra-state-of-the-art approaches, such a designing your process similar to how Matrioshka Brains might be built around a star.

Ignoring mythical design capabilities, I'd point out that an army runs on its stomach. And the stomach of a Bradley tank is a fuel tank that is ravenous. Modern militaries live on the back of their logistics branches which bring fuel to the front lines. If it was even remotely close to possible to produce a bunch of automated war robots on the front lines with nothing more than a cargo container of fuel, the military would have been all over that by now. Such a capability would be such an I-Win button for a military that you can't even fathom how quickly they would pursure that tech.

Given that we have no evidence of such approaches, I think it's reasonable to assume that the idea falls apart.

But there's a silver lining.

You need steel for your SR. Something has to be going out to get that steel for you. It needs to be smart enough to identify the correct alloys of steel that you need, cut them up, and bring them back to the shipping container for further processing.

In other words, I expect your spider robots are out forging for new resources, taking everything they can find. Have your spider robots seek fuel as well.

Shipping containers are generally found near shipping ships. Large ships like shipping ships and cruise ships can easily burn through 80,000 gallons of fuel a day. It should be easy for your robots to find a way to siphon fuel off of the nearby ships. Now we're no longer talking about fueling this production using a shipping container's worth of fuel. Now we have the hundreds of thousands of gallons of fuel of a ship!

This is how ants do it. When a new queen starts a new nest, the first thing she does is lay an egg which will grow to be a worker. When it hatches, it's primary job is to bring back food for the queen so that she can pump out more eggs and grow the colony. Your shipping container is as immobile as a queen, rooted in her nest, but the spider robots can explore as widely as worker ants.

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    $\begingroup$ I can't help but feel that someone is going to notice an army of killer spiderbots siphoning fuel from major ports. Although that sounds, in and of itself, like a great setup for an action sequence. $\endgroup$ – Cadence Aug 8 '18 at 18:47
  • $\begingroup$ @Cadence That's okay. There happens to be an army of killer spiderbots nearby ensuring that, even if they do notice, they really can't do much about it. It's harder to move ships full of fuel than it is to cut off an electric power grid, espeically when under fire. $\endgroup$ – Cort Ammon Aug 8 '18 at 18:48
  • $\begingroup$ I like where this is going. The idea is to beat the world military powers by staying so spread out that they wouldn't have enough ammo to possibly stop them all. (If soldiers all carry 100 rounds of ammo, and get attacked with 125X their numbers of spider robots, it all becomes mathematics.) Maybe the initial wave of the assault takes over fuel depots, etc. That would slow down counter attacks when they realize that wiping out the world's fuel infrastructure would hurt them as badly (or worse) than it would hurt the EG $\endgroup$ – SvdSinner Aug 8 '18 at 19:51
  • $\begingroup$ The spiderbot production could even begin while on a ship. If they are stealthy enough, they can increase their numbers en-route to port, then offload some of their numbers to the port city to wait until the attack signal. Considering how much shipping goes on daily, and how many ships there are, you could have hundreds of spiderbot queens producing and offloading boots all over the world. Added bonus of taking over the ships after the attack begins, crippling supply lines. $\endgroup$ – Starpilot Aug 8 '18 at 22:58

One billion dollar solar panels.

If you want your factories to be totally autonomous, they need some kind of renewable power (assuming that you don't want to be sending them resupply shipments at intervals). Solar is probably the easiest to have a factory deploy on its own, and is most broadly useful; if you're relying on wind or water power, you're going to have a limit on how many locations you can use, and you might run into problems getting the factories to reliably engage with local power.

Jet fuel will melt steel ingots.

If you're okay with your factories having a limited supply of power, the question becomes how to cram the most of it into your limited space, and honestly, in this arena it's tough to beat petrochemicals. Hydrogen is lightweight, but it doesn't pack well; pressurizing it requires a lot of bulky and heavy steel tanks. Natural gas has similar problems. You might want to look into different combinations of engines and fuels to see what will provide you with the best overall bang for your buck; I suspect it will be some type of aviation fuel, since they're already intended for use in a very space- and weight-sensitive environment.


Mr. Fusion.

Mr Fusion https://backtothepredictions.com/mr-fusion/

I understand that in the future we will have these. Your genius might need the next larger model for smelting iron but that is fine. One spiderbot can be in charge of feeding metal chips and waste rubber into the hopper.

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    $\begingroup$ The OP was specifically looking for more believable techs, and specifically nixed nuclear generators because of that. However, I have to admit, Mr. Fusion was the first thing I thought of when I read the problem. As an added bonus, I think the Delorian would fit into the shipping container, so if the evil scheme fails, he can always escape by traveling in time! $\endgroup$ – Cort Ammon Aug 8 '18 at 23:04

Wireless Transmission of Power

Inside the shipping containers is not the power source itself, but finely tuned, futuristic, power-absorbing antennae that absorb energy from a power source placed somewhere very safe (the moon? orbiting earth?).

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    $\begingroup$ Tesla would be proud! $\endgroup$ – Cort Ammon Aug 8 '18 at 18:33
  • $\begingroup$ I don't want to be in that transmission field, the amount of juice you'd need to be putting out is going to cause secondary effects, that would be a very mild side-effect. $\endgroup$ – Ash Aug 8 '18 at 18:48
  • $\begingroup$ This has the added benefit that you could leach off of the public power grid at first, then in your story once the public power is cut in order to stop the factories, then the antagonists own power transmission source comes online and lets them continue. $\endgroup$ – Loduwijk Aug 8 '18 at 18:50
  • $\begingroup$ @Ash Lasers or Masers could be used instead of regular radio waves $\endgroup$ – 0something0 Aug 9 '18 at 2:10
  • $\begingroup$ @0something0 At the kind of wattage you'd need to punch through the atmosphere don't miss the collector or you won't need robots to devastate the scenery. $\endgroup$ – Ash Aug 12 '18 at 11:04

Obviously you're going to use either a highly charged D-sink, a miniature universe containing only highly compressed energy or a singularity tap, a leashed blackhole from which mass is debited as energy at a rate of E=mc2. Both give locally unlimited energy at almost unlimited density and they can only be noted by gravity wave detectors, they're perfect.


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