Watertight Doors and Bulkheads

* See also Securis
* See also Construction
* See also Sewers in Rapture
* See also Utility Distribution
* See also Airlocks
* See also Tall_Buildings
* See also Trams
* See also TechnicalDrawings (Diagrams)
How to keep Rapture from Accidentally ALL Drowning. KEEPING THE OCEAN WATER OUT ...
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The Crushing Pressure :
* Failsafe Seals 'failing' - report any indicators of failure IMMEDIATELY
* New leaks breaking out every day - need for quick repairs (water fills up pretty quickly)
* Securis doors Warrantee Expirations
* Bulkheads between large building sections have to have self actuating mechanisms so that they seal if the ocean pressure ever breaks thru to either side. Electrical breakers have to throw, valves have to close and open passages ( like Pneumo tubes ) have to be blocked strongly enough to withstand the many (19+) atmospheres of pressure that will suddenly bear down on the entire bulkhead. Obviously the entire bulkhead itself must withstand the pressure. The large opening of doors likewise have to seal completely.
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Rapture Warning Signs
"Workers - Please Remember to - Always Seal the Watertight Door behind You !!!"
Seen in the Foundation Maintenance levels with their many 'submarine doors'.
There would/could be simple monitoring/alarms when doors stay open too long (left open), or adjacent sets of doors are open at the same time.
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WaterTight Section Door On HMS Titanic
Leak-Proofing Rapture : Missing Bulkhead Doors :
Many things they show in the game are simplistically impractical, and didn't include "serious" details of how things would really work. Most was done simply for visual effect ( It is a Game after all ). Again, there's the game production issues of budget/time/effort/rendering limitations when it is a 'shooter game' with a Sci-Fi caricature overlay. It is logical that they wouldn't spend much effort detailing spaces out of sight ( but still might have been indirectly indicated -- AND showing they thought about such things as if it WAS a real place ).
Since we have the evidence of Rapture still being inhabited (in BS2) 20 years after its construction, its structural design could not have been THAT shoddy or ineffective in containing the inevitable leaks ( including an extended period with a lack of competent maintenance ). We see the frequently used AE doors (BS2) still operational, and the Bathyspheres which likewise needed some kind of hefty airlock doors. There would likewise be mechanisms used for emergency bulkheads which close off major portal connections ( normally large openings ) between buildings ( the biggest probably being for Metro Trolley Transit tracks passing between buildings ).
Adequate Bulkhead Door mechanisms would have existed to assure the safety from catastrophic leaks. Employing a mechanism with counterweights adds complexity, and the idea of a simple gravity drop (of a fairly bulky heavy door) but with additional weight added could work for an infrequently used mechanism ( raising it again could be very slow and manually supervised, thus allow simplicity ). Consider though how much (huge) weight is needed to cut through a steel tram frame, so a less massive tandem pair of spaced doors might be used ( redundancy is always good when it prevents a section of the city becoming a Cold Wet Dark Tomb ).
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Big Inter-Sectional Bulkhead Doors :
A number of my Level Maps have these Bulkhead Doors added and indicated, located between major sections of the city and the major connection passages. Emergency bulkheads would only be deployed/activated when required, and not constantly be opening and closing.
Such a barrier would have to seal tightly -- Grooves in walls and a sufficiently deep indent into floor to receive and seal strongly the entire edge of the 'door'. A spring loaded plate covered catchment large enough for any likely obstructions to be crushed/sheared and pushed into by the doors, for which you probably want hydraulic driving force ( and some similar mechanism to lift them again - after emergency is fixed or after routine testing/maintenance - though slower is OK then ). Consider if a Trolley/Tram Car was in the way, the door would have to shear through it to seal properly ( utilizing shear blades on the doors edges to facilitate that ). You don't want any significant openings left by crushed materials, as water pressure at Rapture's apparent depth will pass through even small/thin gaps and fill-up virtually all the air volume in a very short time (minutes). Small hairline openings/leaks could be handled by local pumps while repairs were completed.
Such a Bulkhead safety door (and its mechanisms) would have to be up or down in the building structure within its own sealed space. With the larger size of the portal openings ( versus a 6 X 7 foot Securis door ) these 'big' doors would be quite huge ( and being a flat plate be quite thick enough to withstand the force put upon its whole surface at ocean pressure, with the force being transferred to the door's well anchored frame ). Two inter-meshing doors might work, but would be that much more complicated. You probably would want a bulkhead like this protecting each end of those in-game Tramway Viaducts. IF it was a real logically engineered system running through/continued between multiple building clusters, you might want each Building Cluster's Tram Station sealed separate, and protected by the smaller/simpler Securis doors, and thus requiring only one of these huge/expensive bulkhead door system for the tracks. You would also have man-sized airlocks built into the track Viaduct to allow repairs, to do the pumping out, and the repressurization IF/WHEN such a catastrophic leak took place.
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thumb|center|550px|Bulkheads for Elevator Shafts
The Emergency Bulkheads DESIGN : 
* Them being Drop Doors (so they operate using Gravity as an assist or redundancy (Failsafe)
* A Simple Lock mechanism to hold the barrier 'door' up when NOT tripped/closure-activated.
* Explosive Bolts or some mechanical release mechanism ( foolproof and minimal power using to trigger )
* A piston can't really easily hold that much weight up ( you need rugged mechanical rack/gear/rollers )
* Actuator with Automatic Sensors to detect the catastrophe event (pressure shift) and activate the Bulkhead.
* Remote activation (authorized personnel) ? Manual activation at the Bulkhead site.
* Security measure to prevent unauthorized activation/tampering/sabotage, but accessible mechanism for maintenance/inspection.
* The Bulkhead's opening back up is NOT automatic, as the mechanisms should be made with the least complexity (to be Failsafe) and reasonable expense (Ryan had enough other things to spend money on building Rapture). Opening would be done manually with jacks, and only AFTER whatever caused the emergency has been corrected.
* Built with a 300 percent engineering Safety Margin 
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A Proper Emergency Bulkhead Mechanism :
Not being quite as fantastical ( Fantasy Mechanics/Science/Society/Religion/Lack-Of-Consistency and Cohesion ) as Infinite BS, you can probably reason for Rapture to be built at an appropriate expense, and with the use of available ( and well proven for its time ) era technology and materials/techniques being employed. Simplicity usually also helps with reliability in mechanisms. For Rapture there would be a Systematic and extensive use of such Barriers ... definitely. Nobody is stupid enough NOT to have them and for half of Rapture to drown from one major leak. A meter+ thick slab of reinforced concrete dropping within a reinforced edged slot is pretty effective if those edges can be sufficiently sealed, and it can be seated properly ( not blocked from closing - water at the pressure involved would fill up large volumes quite fast, from a gap any more than a crack ). For aesthetics they would be made unobtrusive ( excusing why we didn't notice them ) - There can be thin veneer over the slots. More substantial 'break away' flooring is fairly simple mechanically ( WHEN the Tram tracks go through a bulkhead THAT is a bit more complicated, but hardly difficult to make workable ).
By leaks, I also would include massive structural failure which Big Daddies likely couldn't solve ( and the pump systems cannot possibly handle ). The BDs also didn't exist ( and were not foreseen ) when Rapture was first built, so humans would be 'it' for all the expected work. Smaller leaks BDs could handle, and probably even were trained to predict and take preventative action for ( ie- "OOOOOM" Sonar sounding out internal cracks in structure components ). This all relies on Rapture being well designed and built from the start which its seems it mostly was.
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Those Airlocks which the game has used as Level transitions could only work for low traffic paths as they restrict traffic/free passage ( by their cycling time ). I suppose they could be located at building/structure 'Break' points - intended flexible connections where they can compensate for some shifting seabed ( minor earthquakes in particular - Rapture is located near a Divergent boundary, and not a Convergent boundary where tectonic plates move at each other and generate significant earthquakes ).
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OTHER Doors That Slam Shut :
Air Vents especially would have automatic bulkhead seals ( probably with redundant sets) as they are usually left open (Pneumo tubes are closed off by the machinery, but also have closeable seals ).
If a major flooding situation happened, water would spray in with great force (like 280 psi) and any air in the space would compress and shoot thru those vents at some similar pressure ( imagine the Little Sister being in that Vent/conduit/ducts and shooting out the other end at several hundred feet per second ).
The truly monumental bulkhead doors are the big openings for the streets ( including Trolley tracks ) entering a Plaza. They are Emergency doors larger than those seen for the train airlocks in the Atlantic_Express stations. They have to be able to handle anything that might get stuck in them and close with enough force to cut any obstruction in half. Pusher bars move to clear any objects that might block the doors guideways. Such doors are usually in double pairs to be relatively fail-safe and can handle any single failure.
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Emergency Bulkhead Considerations :
Any automated seal or a blast door or gate is made up of any number of moving parts that slide/rotate in either direction to open - horizontal, vertical in one or two parts.
Things can get more or less complicated depending on the mechanisms use of gravity ( dropping a heavy door is easier than lifting one into a closed position and its weight may 'crush' obstructions out of the way ).
If the door is for security, then it needs to be firm and resilient to tampering, inaccessible to disassembly and to external damage from at least one side, but securely contained also from the other side to keep the mechanism stable and isolated from accidental damage.
The bulkhead door should be inset within a track for proper securing/sealing and for structural stability reasons. You need safety and security from either direction as a design goal ( either side could have the leak/flood ).
You also have to account for additional space to house the motors, hydraulics, magnetism or whatever tech is employed to operate the door ( possibly several mechanisms depending on the design and the intended function of the door ).
You usually have a space/volume beyond the doorway to act as a door rest/recess into the structure for a heavy door to clear, which increases its material costs. A worthwhile expenditure especially if the door is for safety or security. You need a strong containment wall between the area on one side, the resting space for the door and on the other side - doubling the reinforced surface structure at that point.
The door mechanism requires a full maintenance access from both sides, or you are 'out of luck' when it malfunctions or gets jammed. Even simple repair/servicing otherwise would necessitate some major disassembly and reassembly operation, which is clearly undesirable in most of the environments in which automated sliding doors are used in popular Sci-Fi. If the door itself is damaged, you would have to completely remove it from its track.
If access to the mechanism is meant to be sealed away from both sides, you'll also need external access to be inaccessible/secured from the immediate area on either side, which further complicates any maintenance process and overall design of the entire complex housing such doors.
The Bigger the doorway and the doors, more Complicated and resource required for the entire thing.
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Various Seal Mechanisms Between Building Structures and Other Things :
Rapture's Utility system is composed of Vents/pipes/cables/etc ... have to connect through the compartmentalization that makes up Rapture. Materials expand and contract at different rates, so there will always be some kind of gap involved, which needs to be sufficiently secured and plugged with a strong (preferably narrow) flexible material (Seals). There are such transitions especially at the points where prefabricated building sections are joined.
When any major leaks happen, causing increased pressure in a compromised section, the seals beyond it at least minimize/contain the leakage spreading until a time when the leak's cause can be fixed.
The doors which seal sections (in MY design plans) are often in sequential pairs for a safer redundancy, and which allow immediate passage unlike the 'cycling' Security Airlocks we see in a number of places ( Those are used for game 'level' transitions which you CANNOT just walk through ... ).
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Real Submarine Section Doors are Made Small - Must Resist Pressure and Force :
http://adjunct.diodon349.com/US_Subs/DBF_photos/Guppy_Book_guppy_1A_watertight_door.jpg
http://www.williammaloney.com/Aviation/USSAlbacore/GalleyNCrewsMess/pages/13WatertightDoor.htm
Most submarines have a maximum operating water depth (much) less than Rapture's depth ( The one I figured which has a 'street level' of about 600 feet ).
MMORPG Rapture's large sliding Section doors are big enough to let Trolleys go thru their portal ( and similar doors are used for the AE train Airlocks ). Such large doors have to be massive to resist the water pressures that would act against them ( same problem as large single-pane windows - Leverage works against them ). The Bathysphere airlock doors are smaller, but have to be just as strong and operate constantly without failure. The common Securis doors ( used to enforce local compartmentalization of buildings ) are yet smaller ( about 7 foot tall by 6 foot wide ) and so can be thinner/easier to move.
Submarine style doors are simpler (cheaper) than the various automatics seen in Rapture. Down in the Basement/Foundation levels ( where Maintenance Workers usually only go ) they are used extensively to partition off the drainage sections ( each section has its own pumps ). Players who go down to those levels will be opening and closing alot of those manual water-tight doors.
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Pressure_Doors.PNG
AEdoors2.jpg
SecurisDoor.jpg
AEdoors.jpg
SEC111.jpg
BioshockMovieConcept2.jpg|Bathyspheres require doors able to withstand the same high pressure
Realdoor.jpg|Real Submarine door
SubDoor.png
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Stuck/Broken Pressure Seal Doors In 'Wrecked' Parts of Rapture :
Don't try to blow them open with explosives - damaging them will cost a great deal of effort to get them working again or to replace them ( having them working is highly desirable for YOUR safety ). The City Council has posted warnings about doing things like this.
Actuating pistons - repairs, powering units, triggering sensors - simple, robust, critical.
Alternate access to other side of bulkheads - maintenance/emergency airlocks usually in parallel ( sometimes a round-about path to get there ). The bulkhead doors are designed to LOCK when activated til authorities confirm the situation is safe and reset them.
Some were welded shut during the Faction Period to keep undesirables out ( like Lamb's Family zombies w)
Difficulties in working underwater to do repairs. Impairments/damage to door mechanisms caused by long immersion in salt water ( even though they were designed to largely resist that environmental factors. They still can require replacement/major repairs ).
Numerous Player missions will involve opening/repairing/maintaining/sealing of doors and bulkheads ( major operations that can require alot of cooperative activity as part of New City expansion ).
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Pump Control Substation/Pump Station :
Those huge pumps (Sirens Alley) are rather large for normal structural leakage and Rapture pressure sections are not expected to flood. Smaller local pump units ( like in the basement of each building -- and likely in redundant sets ) would be more logical and require fewer/shorter pipes/small sumps. Large portable emergency pumps distributed throughout the city ( transported where needed by the utility Trams or even submarines ), with local ocean outlets and adjacent-section draw/drain pipes at strategic points, would be less expensive and more flexible ( it would save literally miles of excessive piping and inefficient pumping ).
If a section did flood (catastrophic damage), it would flood so fast that no pumps could keep up ( ocean pressure would be equivalent to a high power fire hose from every square inch of a hole ). Such a large leak would first have to be repaired and then construction pumps would empty out the water. There would be no rush, as the destruction was already done - no one inside would have survived. Efficient 'normal' pumps can be made small and would NOT require HUGE sumps to drain. Centralized 'flood' pumps just don't make sense. The Dionysus park recovery would have had pumping done by portable equipment - not some permanent huge machinery in an adjacent building.
All buildings are subdivided into sections protected by self-closing doors (ie- Securis Doors) that help to isolate flooding.
The doors are strong enough to hold back full sea pressure during a major leak situation. All utility conduits close ( and major ones have independent protection ) so that any possible leak is limited to small sections of any building. All building sections were designed with more than one access path ( and/or protected escape paths ) to prevent Citizens being trapped by a leak in any section. Automatic Pressure Doors can be overridden to allowed trapped Citizens to leave the damaged section -- if the large leak is found to be slow enough not to imperil the entire structure. Many buildings provided safety airlocks which also could fulfill this operation, with full safety.
Would having evacuation drills periodically make sense in old Rapture ?? Or would that kind of thing make people more anxious about where they really are 'under those crushing depths'. School children might have basic drills on where to go ( 'duck and cover' kind of thing ). Maintenance and security personnel would be trained to handle the situations should they arise ( were very few incidents in old Rapture ).
New Rapture is a bit more precarious, with the Citizens being all too aware of what can happen and The City holds regular drills especially of the Automatic bulkheads and evacuation procedures. This subject would be yet another source of possible City related quests/missions for the MMORPG.
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need pix 
That Wrecked Trolley and Track, and a Safety Barrier that Seems to be Down :
BS1 at the Athena's Glory end of the Trolley Viaduct on the Olympus Heights level.
That end of the Tramway is blocked off with alot of debris. Ignore that the tracks (simply stop) don't continuing properly, when they should ( that will be well-fixed in the MMORPG ). There is what appears to be a flat solid wall behind all that wreckage. 
I would have emergency barriers at such strategic spots to protect large areas from being flooded during a containment failure. So here, one reason such a theoretical barrier may be down is that the Athena's Glory building DID suffer a catastrophic leak, and IT was then closed off from the rest of the City. 
I don't think the game designers considered anything in that scene beyond 'flavor', and we don't see anything like an unlowered barrier mechanism even on the other Viaduct end, where we DO have a clear unobstructed view. I forget if there was in-game any indicator that Athena's Glory was still inhabitable ( go back and look to see if any windows are lit ). 
I would have the buildings themselves also have some internal bulkhead protected sections, and multiple paths allowing people to get out/be rescued from any "Secured" (locked down) sections ( and to allow controlled ingress for repairs ). There would be emergency barriers at many other points ( like for the Utilities which have their own separate network system of widely interconnected pathways/accesses ).
I would say that spot is the right place to put a bulkhead. A monolithic sliding slab would be a good way ( one view there even looks like it has edge reinforcement slots the slab would move within. ) Smaller doors/portals into the buildings along main paths would be atypical ( when the Trolleys need large ones ). You'd think there would be more decorations around the door, but those always could get blasted away or pulled off to build barricades ( alot of real Art Deco was cast Terra Cotta or Pressed Metal panels fastened to flat structure surfaces ).
A simple effective (reliable) mechanism is all that is required - not something expensively fancy. These Emergency Bulkheads, being part of the interior, aren't constantly exposed to Salt Water, so they aren't really subject to significant corrosion problems ( allowing cheaper steel Rebar to be used for their reinforcement and Steel plate for the working surfaces/mechanisms ). 
Very Important is : to be reliably deployed FAST in an emergency. And THEN once the problem was solved ( repairs of the major leak ) it can be 'Reset' -- THAT not needing to be done so fast. Actuators only have to drive the bulkhead one direction, and the reset can be manually done ( using repair jacks, etc ... ) 
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