Parma Antonio & Figli, Milan

[wylk]

Well, maybe not this exact door but...I just found an emergency door inside a vault door at The Vault Cafe in Phoenix, AZ.

Wow, too bad I'm 644 miles away! Some observations, things to look for:

The door seems way older than the building (and mounted outside?). I wonder where it came from originally? Who built it?

I don't see any combination dials. Are both doors automatic?

The crane hinge on the emergency door looks like it's unusually articulated with three sets of hinges instead of the usual two sets. This makes some sense because the emergency door's crane is anchored to the big crane and the two have to move in relation to each other.

The main door crane hinge blocks have some sort of brass caps on the right and left (some missing).

While there are pressure bars for the main door, there aren't any for the emergency door.

There is a door stop block on the lower-right, perhaps latching.

Google Images came up with the image below. Something like this fooled me before; it's just a big poster print stuck onto the glass.

[VaultDoors]

Strauss also patented a door-in-door, US 901,047:

Attachment 13223

Found another 'Door-in-Door', US 411669:

[Huw Eastwood]

Found another 'Door-in-Door', US 411669:

Looks like another example where the secondary smaller door serves only to provide access to the bolt throw handle of the main door. With all the extra manufacturing involved of the door on door design, it makes me wonder whether there was an unusual application that needed this, or was it down to the boom years and everyone just trying to come up with something different.

[Chubby]

It's a bit like the idea of the Chatwood Milner Manifoil "blister" that used to be used on some government safes in UK. An easy way of providing dual control.

[Huw Eastwood]

That's weird you mentioned the Manifoil blisters Chubby- I'm actually doing two on the bench right now! One of the early square pattern and a later round one.

yes there's definitely a similarity, but remember the Manifoil blisters were fitted onto existing safe doors over the keyhole to block key access to the existing lock underneath. This was More because the MoD insisted that everything had the protection of the Manifoil, including the old war department safes and anything else old without it. It was an easy way of providing dual control like you say, and some were used as dual with different holders to comb and key where situations demanded it, but the idea was more down to an easy solution to Manifoil protection on everything and most users had both the key and the combination.

The unusual design of the vault in the last pic here has no visible additional locking under the small secondary door, it's straight through onto the handle to withdraw the main boltwork, so it doesn't appear to serve a dual control purpose and seems an usual idea all round.

My bet is its just one of those oddities from the booming years when the industry was growing at a tremendous rate and it was straight to the patent office whenever they came up with something new.

[Huw Eastwood]

Here ya go. A blast from the past. Was originally going to just get them working, but will now more than likely strip them down for painting and do the full works on them.

[Chubby]

Of course with some government storage the important thing is that you know if it has been compromised and that is where the blister was so useful. As you say they were a useful way of applying manifoil protection which I think was mainly for the above reason. How much extra security they afforded I don't know. Sticking out as they did they must have been a fairly easy target. Again, though, that wasn't really the point. They would be on a base with a guard 24/7. I have seen large amounts of cash kept in what was known as a "sub standard plate safe". Frankly it didn't matter as the whole area was so secure that the safe was purely to keep the cash together and restrict access to the paymaster or adjutant.

That's weird you mentioned the Manifoil blisters Chubby- I'm actually doing two on the bench right now! One of the early square pattern and a later round one.

yes there's definitely a similarity, but remember the Manifoil blisters were fitted onto existing safe doors over the keyhole to block key access to the existing lock underneath. This was More because the MoD insisted that everything had the protection of the Manifoil, including the old war department safes and anything else old without it. It was an easy way of providing dual control like you say, and some were used as dual with different holders to comb and key where situations demanded it, but the idea was more down to an easy solution to Manifoil protection on everything and most users had both the key and the combination.

The unusual design of the vault in the last pic here has no visible additional locking under the small secondary door, it's straight through onto the handle to withdraw the main boltwork, so it doesn't appear to serve a dual control purpose and seems an usual idea all round.

My bet is its just one of those oddities from the booming years when the industry was growing at a tremendous rate and it was straight to the patent office whenever they came up with something new.

[VaultDoors]

it makes me wonder whether there was an unusual application that needed this, or was it down to the boom years and everyone just trying to come up with something different.

It may have been a cost saving measure instead of building a separate emergency door structure. Perhaps it was used to provide more space for safe deposit boxes if the vault was small to begin with and they didn't want to use wall space for the emergency door.

[Huw Eastwood]

Is it an emergency door though? I'm referring to the last one you posted Ed US 411669.

The small secondary door in the second sketch just opens to reveal what looks like the central hub of the main doors boltwork- with a 'T' shaped handle in the vertical position in the centre. It's basically a main door with a hole cut in it and a handle to operate the boltwork, covered by the smaller door which locks. Once the small door is open, you simply turn to handle to withdraw the boltwork on the main door.

It doesn't appear to serve a dual locking purpose as it gives access directly onto the handle for the main door, but it also presents a problem as an emergency door as opening it means you're confronted with the boltwork and handle behind it. It'd take a seriously slim person to squeeze through the gaps In the mechanism!

[VaultDoors]

Yes, I was referring to the other Door-in-Door examples. Sorry, I should have clarified that. I was able to visit a real Door-in-Door yesterday (by HHM) at the National Bank of AZ and took over 100 photos that I will be sharing soon. I wonder how many were actually built, seems very rare.