Vault door

Vault-Tec, when constructing their Vaults made sure that their inhabitants are well protected from outside threats. One of the key pieces of engineering that was protecting the dwellers was the .

Vault Blast Door
A Vault requires proper sealants against radiation and other hazardous elements that may be created in the event of a nuclear war, to properly protect its inhabitants. Vault-Tec, in their infinite wisdom, used a number of different door models in their shelters, the most common being the tried-and-true Seal-N-Safe Vault Door Model No. 343 (denoted as such in the Vault 15 townmap).

Seal-N-Safe Vault Door Model No. 343
Most common model, this door was first used in the demonstration Vault beneath Los Angeles. It had a smooth outer surface and opened outwards, rolled to the side by an extending mechanical arm. It was a very compact design, usually followed by a long air lock, ending in a high security door, with two layers of steel and a slab of lead in the middle.

East Coast model
A far more crude model was used in the East Coast Vaults, this particular one opened inwards, with the use of a hydraulic arm. They are shaped like cogs. When opened a large mechanical arm swings down from he ceiling and open the vault door from the inside. It pushes inward and rolls off to the side allowing access. This manner produced an extreme amount of unhealthy grinding noise during opening, easily damaging one's eardrums.