Could this tie into why the guy was gasping and [censored] when he came out of the vault?

Also. Can my submarine vault be yellow?

One guy left, from the yellow submarine... the yellow submarine...

This could certainly explain why he catches his breath when he reaches the surface. Notice also that the top of the lift-shaft is sealed by some kind of blast door until just before he emerges. The level of the blast door, relative to the top of the lift-shaft, corresponds with the 'gap' we can a few feet below the surface in the post-war scene of the trailer. This suggests that even inside the lift-shaft, the air pressure is different to that outside.

I think I just figured out what the red wheel is actually for! It attaches to a valve used to depressurize the lift-shaft, so that the vault inhabitants can then go down to the main vault level. This ties in with the yellow pipes we see around the lift area that will be used to quickly expel air during the depressurization. As I said earlier, the writing on the vault door suggests that when we access the door controls, the area immediately behind the door is also depressurized, and the door then opens so we can go through. The last area is the inside of the vault itself, which will be through a third door (similar to the sealed pressure-doors inside a submarine). This will be where we find the cryogenic pods. As I suggested earlier, once our 5 survivors have entered the main part of the vault, one of them seals the inner-door shut, trapping the scientist outside in the area between the two doors. This air pressure in this area is then rapidly increased to seal the vault door, and the scientist is killed.

If this is correct, then it also confirms my theory that no-one was actually inside the vault prior to our 5 survivors and the scientist getting in. If anyone else was already down there, the air pressure would have killed them.

When you see yellow pipes or valves, that means pressurized air. All gases in the US have a color identification. Oxygen is green and so on. You need the vault to be pressurized because of the cold temperatures. High pressure prevents the formation of ice at very cold temperatures. This is something I've been saying since day one of the trailer.

This ties in very nicely with the above theory then, and it also pretty much rules out anything involving 'lots of survivors' going down into the vault. The high pressure would prevent our survivor's from being turned into ice-cubes during cryostasis, and the pre-requisite to depressurize before entry means there was only one trip down, which was immediately after the blast.

Pink Submarine > Yellow Submarine.

https://www.youtube.com/watch?v=EYekeKr8r5I

Just figured out that the security guard makes it into the vault as well. So that leaves us with the protagonist and their family, 2 of the civilians we see above the vault, the scientist and finally the security guard. This makes a total of 7 people.

EDIT: the security guard is required for plot purposes.

What, you mean for a 10mm pistol?

The high pressure would of course ensure that nothing breaches the vault, but there is another far more important reason.

Extreme high-pressure stops water from expanding as it freezes, and every cell in the human body is around 70% water.

Let's just say that the scientist, the security guard, and even the 2 civilians each have their own part to play in what happens inside the vault.

It's certainly a good theory.

Thank you. I've been working on this since the trailer was first shown, and I think I've even managed to figure out how they get out of the vault and a lot of what comes after.

When i read the title i was like Huh, but looking at your theory it does make sense. Why else would there be a lift and then a separate vault door, instead of just the standard cave and vault door like in FO3 and all other games. I like the idee about the scientist too, could be he got stuck there during the closing of the vault and either died of asphyxiation, hunger or thirst, or even by suicide using the 10mm gun.

In the town, where I was born, blown to hell, as far as I can see...

But I carried on my life, in the land, blown to smithereens.

So we walked under the sun, met a dog, happy as can be.

Now we fight against the waves, of enemies in our T-51b...

This theory really makes a lot of sense...

I think he/she (the OP) would only like to point out that Vault 111 is built like a submarine, not entirely a real submarine, and he coupled it with the theory that our character is cryogenised...

So, yes, he/she only pointed out that the Vault 111 is pressurised like a submarine in order to support human cryogenesis...

As someone who used to work in freezers, I can concur that there is certainly a certain amount of pressurization in those things...

Also, F--- you, Sam's Club, my middle finger raised.

Well you are near a coastline. They may have figured the apocalypse would cause that area to flood which is why the vault entrance is designed unlike the others that we see.

If I recall, according to Fallout 2, the vaults were designed as a means to study various elements and challenges posed by space travel, as before the war, it was the Enclave's intention to colonise another planet, studying such things as radiation exposure, demographic imbalance and isolation for prolonged periods, given that space travel would take thousands of years to get to the next star system. For Vault 111, I guess was to test how cryostasis will last over a prolonged period - both the subjects and the equipment (you don't want to get to the 50 year mark and start to suffer critical system failures), and how it effects different demographics (men, women, infants, let's pretend Mrs Neighbourino was in the pudding club). This form of cryostasis would be compared in direct comparison to Vault 112's stasis experiment where the cost benefit anolysis of 111's infrastructure intensive form of stasis, compares to the more self contained virtual reality units that stimulate the mind but the body weakens (I imagine, given a pod's presence in Anchorage, that these pods were in fairly common existance but the long term effects were relatively unknown and unstudied).

And Van Buren's Boulder Dome is exactly what you described here. Dr Presper and Coleridge were both to be from the pre war years, placed in cold storage at Boulder Dome and awoke many years later, joined the NCR then betrayed them. Both have pipboys in the game.

The deep diving submersibles are pressurized, I believe......but military submarines are not. The pressure on the inside is pretty much normal, outside is quite a bit higher at the ususal operating depths. For an amusing discussion of that, watch the scene in "Down Periscope" when the retired Diesel boat guy explains it to the newbies. lol