How long could we preserve technology post-apocalypse?

Question

If we specifically engineered a doomsday bunker to preserve technology and weaponry, what could we preserve and how long could we make it last? I'm looking at a timeline of circa 300 years.

You can assume that it has power (e.g. geothermal) and is completely undisturbed until it is opened. Any type of preservation we're currently capable of is on the table: airtight, vacuum sealed, submerged in oil, wrapped in your grandmother's couch cover, etc.

I'm looking for things that would work "out of the box", so a gun without working gunpowder isn't much help. Would any kind of explosives still work? Nuclear weapons? Computers or electronics? Motors (with fuel)?

EDIT: Sorry, first time on the site. Thanks for the responses. I did read the other posts, but they were all centered around how long our current technology would remain working. I didn't see anything about how long things could last if we specifically tried to preserve them.

I'll try to answer/clarify things here.

Say the human race knew that we were facing an extinction event like an asteroid collision and wanted to preserve ourselves. We built a number of bunkers to house and preserve the human race. One of these was a military bunker that did not contain people, but was designed to rearm them whenever they were able to come recover its contents. What would they put in it and how long could they make it last?

Our hero discovers one such bunker. What would he find it in it? Assuming he has all the knowledge necessary, what could he pick up and use more or less immediately?

EDIT #2:

Good point on the word "technology". I mean stuff. Maybe some specific example questions would help:

Assuming the bunker had a continual working geothermal power source, could they build electronics that still worked? Computers?

My current version of the bunker is protected by a large blast door that requires a motor to open it. Ideally, I'd like to have working electronics and motors so that a single person could open it. For example, a modern keypad and keycard. Could that still work? Is there another way?

I'd like our hero to be able to fight his way back out of the bunker with some kind of advantage. For the sake of this discussion, assume he can figure out any technology. It sounds like it would be possible to preserve guns and gunpowder for that long, so that would be an option for this.

There also needs to be a reason that the new nations of the world want to get into the bunker. Guns are a good motivator, but bombs are better if they would keep that long.

Hope that helps and thanks again.

Answer 1

Simply placing a device in a vault and hoping somebody finds it is by technical definition preserving the technological artifact itself, but it is not preserving the knowledge of what it's for and how to make it. If you handed a modern smart phone to a guy from the 17th century he wouldn't even know what the heck its intended purpose was, what it was made from, how to use it, or how to make it. It might as well be an inert glass tile to him.

In order to preserve the technological knowledge just the artifact isn't enough. you need to be able to not only explain what it is and what its for, but how to use it, what its made out of, how it works, and how to make it. This becomes a GARGANTUAN task when you consider that most modern technological devices require other machines to make, which themselves require machines to make them. Though seemingly counter-intuitive you want to store simpler components and devices and trust that your regressed descendants will be able to discern useful tasks to apply the devices to. Things like steam engines, electric motors, dynamos, batteries, simple radios, etc etc. In this manner your descendants who fell back to a pre-industrial level can create and combine things in the most useful ways to themselves. Simpler components of more complex devices also means that they can find existing artifacts left over from the old civilization elsewhere and discern their function and have a basis for back-engineering the remnants of society on their own.

Rather than trying to hoard a cache of every piece of technology in society you ought to instead plant a sort of seed for your descendants to re-grow their own technological prowess with.

Answer 2

Modern 5D data stores could keep all of known history in a stack of disks that would fit in a soft drink can for the estimated remaining life of the sun. That's technological information storage, technological artifact storage is both more simple and more complex:

The problem is going to be with fuels, propellants, and explosives; you can have guns easily enough, grease and vacuum bags will keep most metal built mechanisms good for decades, but bullets are tricky. By their nature fuels, propellants, and explosives are unstable and readily oxidised, they break down or burn when left alone for long periods. Propellants and explosives are especially problematic because they are self-oxidising so even in a vacuum they will decay and possibly detonate spontaneously. You could potentially store bulk chemical components and processing equipment to make the fuels, explosives and propellants you need to run stored machines with solar power equipment kept in storage to kickstart things but I think that's as close as you're going to get to army equipped and ready when you open the bunker.

Answer 3

This way of thinking is very... American. You see, preserving weapons for later use. Against whom? The whole technological advance was made because some people wanted to kill people who didn't wanted to get killed.

The use of black powder by Europeans. In the early age of using it regular cuirass was able to deflect bullet and protect the owner. So we figured out how to kill them even if they were wearing it.

Why do you need automatic, systematic, hydromatic weapons? To hunt? A string and a stick would suffice and you would call it a bow.

Conquer? How many people are left on earth that you need to kill them by the thousands a day? How large army you will gather?

Imagine this, your hero discover said bunker, he take more shiny metallic weapon. A rail gun. And he go for an adventure to avenge his gather because his name is Inigo Montoya. He wait, he shoot, he miss. He is killed with a sticks and stones because he can't figure out what the quack "reload time" is.

What would be more needed is technology to make good quality steel. Easy to preserve in form of pictures, chemical reactions, sample example. How to make artificial fertilizer. How to acquire water and purify it.

Use of nuclear weapon in post apocalyptic world scare us because we don't live in such world. If in post-apo you have N-bomb what you gonna do? Set it off in the most inhabited city and kill all 2 thousands of it citizens?

Also, for "how to preserve technology" see Cheyenne Mountain Complex and Svalbard Global Seed Vault.