Vault door When Vault - Tec constructed their Vault s , they made sure that their inhabitants were well protected from outside threats . One of the key pieces of engineering that protected the dwellers was the Vault door . Door variants . Standard door . A typical door used in the Vaults , composed of two pieces that connect and seal ( with the use of special interlocking cones ) when the door closes . An emergency override handle is placed above the connection seam . Under normal circumstances , when a hatch is locked , only an experienced locksmith could lockpick the hatch . Each door is operated by hydraulic motors that effect 3300 lbs of pressure when operating the door . Doors are designed with three safety features . The first is a caution zone marked by yellow lines on the floor . The second is an automated system that reverses the door if it detects an obstruction , and attempts at closing the door a few moments later . If the obstruction remains under the door , it will continue repeating this motion until powered off or the door finally closes . The final feature is a power box next to the door , which can be used to shut off electricity to the bulkhead and seal it . Under normal circumstances , the lamps on the power box are green . If the power to the door is cut using the switch , they glow red . Interior doors . The Vault Door is a type of electro - mechanical door used in the Vault - Tec Vault s for creating physical barriers between corridors , rooms , and stairways . The hatch is a heavy steel door , of either one or two pieces , supported in a heavy steel frame built into a wall and powered by concealed powerful hydraulic motors . Security door . This model is identical in function and safety features to the door above , except there is a centrally painted white vertical band with a stop sign and the words " " No Access - Authorized Personnel Only " " . There are downward pointing chevrons above and below the text . Maintenance hatch . This is a one - piece hatch . Hydraulic motors swing it 90 degrees on a hinge when opening . On one side of the hatch , there are two circular indicators . When the hatch is closed , both indicators display diagonal red lines on a white background . As the hatch is opening , the indicators display OPEN in red text on a white background , while the other shows STAND BACK in red text on a black background . 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 used a number of different door models in their shelters , the most common being the ' 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 . In " Fallout Shelter " , player - created vaults use the Seal - N - Safe 343 , which can be upgraded to the nine cog model seen below . Nine cog model . East and West Coast . A different model was used in the East Coast and the Mojave Wasteland Vaults ; this particular one had a larger opening diameter and was much thicker than the Seal - N - Safe 343 . Usually mounted near the door is a warning light and siren which are both turned on during the first few seconds of the door ' s opening or closing cycle . One installation has the ability to mount security cameras beside the door . The East Coast model is opened from the inside using a large mechanical arm mounted to the vault entrance ' s ceiling . When the door control panel is used to open the door , the arm swings down and pulls the door inward and onto a gear rack built into the entrance floor , allowing the door to roll aside . Inside and outside the vault , there is a control panel that activates the vault door from either side , however the controls can be locked with a password . It is assumed that the password is a voice command , as there appears to be a microphone and speaker on the console . Commonwealth . A different model was used in the Massachusetts region , and also in Vault 118 in Maine . This model is very similar to the doors seen in the Capital Wasteland and Mojave Wasteland regions . When properly maintained and serviced , the door has a dark grey base , and has a bright yellow center and outer rim . The Vault number is neatly drawn in black . On the rear - side of the door are black - and - yellow warning symbols , and a light bearing the text " clear " mounted beside the door . Within the base is a yellow purge valve with a hydraulics tank . It is one of the only doors so far known to have text on the door . Vault 111 in particular has an elevator , an additional protective measure as a nuclear blast wave would pass over it . leading to the surface entrance to the Vault . It is a large convex structure , and has a vault - shaped elevator and blue and grey paint throughout the structure . It also bears yellow pipes , gas tanks , warning lights , black plates dotted throughout , and a red in - take valve . From the inside and outside , the vault door is controlled by a control panel , but unlike its East and West Coast counterparts , the Commonwealth control panel requires to be connected to the adapter plug of a Pip - Boy 3000 Mark IV to unlock the controls . Also , unlike the Capital and Mojave Wasteland Vault doors , a large mechanical arm rolls the door to one side instead of the door simply rolling to the side by itself . " Fallout Shelter " . Every Vault in " Fallout Shelter " , has the same standard model of door . When the vault door is upgraded to Level 2 , the nine cog model is used .