Automated Sliding Doors in Science Fiction

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Don't make sense to me in most cases. Especially if it's a seal or a blast door. Note that in this context, I mean any automated door or gate made up of any number of moving parts that slide in either direction to open; horizontal, vertical or diagonal.

• You have to account for a back space beyond the doorway to act as a door nest for the door to open in the structure, which increases material costs which may or may not be important depending on the context but especially so if the door is for safety or security, as you still need a solid frame between the area on one side, the nesting space for the door and the area on the other side, ie. double the reinforced surface.

• You also need to make them indented with a track for security and stability reasons if safety and security from either direction or both interchangeably is a design goal.

• Things can get more or less complicated depending on gravity.

• You have to account for additional space to house the motors, hydraulics, magnetism or whatever tech is employed, to operate the door and possibly several of them depending on the design and the intended function of the door.

• If the door is for safety or 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.

• That requires a full maintenance access to the mechanism from that other side or you're fucked when it malfunctions or gets jammed. Otherwise a simple repair could necessitate a wholesome disassembly and reassembly operation and that is clearly undesirable in most of the environments automated sliding doors are used in sci-fi. Doubly so 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 need external access inaccessible from the immediate area on either side, which further complicates the maintenance process and overall design of the entire complex housing such doors.

• Bigger the doorway and the doors, more complicated and resource demanding the entire thing.

For instance, when I think of the huge vertical gates in Aliens that the Armoured Personnel Carrier goes through in the colony, or the immense hangar gate on Sulaco that Ripley walks through in power loader, I can't help thinking about the overall design:

(1) you need as much space as the huge gate itself above the gate itself

(2) mechanism has to be strong and reliable enough to suspend that much load in open position indefinitely

(3) structure housing the mechanism must be even stronger

(4) for the colony gate example, how the fuck do you even access that shit if it gets jammed while up and open; ceilings weren't that high in there (as opposed to Sulaco cargo bay/hangar), so the door nest must be occupying the mezzanine between the current level and the upper level which, in turn, would potentially render the gate susceptible to damage from the ongoings of the upper level since there would be so little insulation between the two. Oh but I thought the mezzanine held the air vents the aliens crawled through and possibly other infrastructure? Those go around the door nests? Okay.

(5) Yet worse if it gets stuck while down and closed and a lift truck doesn't help (assuming the designers didn't just rely on the gate lying down on its own weight to seal it closed. Some kind of locking mechanism, perhaps). How and where the fuck do you move that much load? Since it's supposed to be sturdy, I imagine you can't -or at least shouldn't be able to- remove it from its tracks without a major disassembly/reassembly operation.

They are, however, okay when they don't serve a hard safety or security purpose. Labs IRL use such for containment, after all. I loved that they mostly used hinged and hydraulic doors in Battlestar Galactica.

Anyway, what are your thoughts? What do you think of far future in regard to doors? Anything I'm missing?

Good observations. I can't say any more about doors, but for the same practical reasons, I don't think there will be computers or activation panels with cool flashing lights, or screens in the far future. Everything would be wireless and routed directly to your brain.

For structural doors, it'd make more sense to have multiple overlapping doors, I think. That way the extra room to house the door wouldn't be as great on any individual wall. You could assemble a foot thick barrier from a pair of 6 inch panels and that way only need an extra 50% thickness of the wall housing each panel rather than an extra 100%.

I kind of assume most of these things are only there to protect specific parts of the ship though, so there's really no need for the wall housing the door to be as reinforced as the door itself. It's not like the sliding door on a train where you want the whole train to be equally durable when the doors are closed. You just want, for example, the area people are in to be protected and if the emergency hazard the door is stopping overflows into say, the water reclamation system, who gives a fuck? Let it burn, fix it later. Same logic applies for containment stuff. You need thick walls around the weapons system in case something fucks up, but there are no hazards among living quarters that are going to warrant significant structures.

In short, an emergency door only needs to be strong when it's closed. If someone blows up your emergency door before you've closed it, they could have blown up whatever the door was supposed to protect anyways. Nobody worries about how quickly you can ruin a safe's ability to work properly when it's already open.

Spend time on any naval vessel and you'll see that sliding doors is just a way to secure them when open, something very necessary on those types of vehicles.

Vaguely on-topic:

I was watching Aliens last night for like the millionth time, and I noticed that when the marines first enter the complex, there's a partially open 'sliding door'.

A marine on each side pulls on the door-halves but they only budge open a few inches while making a grinding sound. On the 2nd pull they try harder, opening the doors most of the way.

I thought this was very cool attention to detail by James Cameron. Most directors would have just let those doors open on the first pull (they're just foam after all). I'm sure he coached them to do it exactly that way, using the correct sound fonts to match. Directors like that are a dying breed

Naval as in military? Never seen one in a civilian ship. They all had good old hinged doors. Hatch type for outer doors. Classic in interior. I don't know about military vessels, though, but I don't remember any from films, games etc.

Also, I think all doors in ISS and all the past modules are and were hydraulics assisted hinged hatches.

I've got nothing further to say on IRL applications. The way it is used in sci-fi films, it seems as though every single door is made to seal and protect from either side. Whenever one is locked or jammed, some people die or have to find another way. In past/present time films, there is usually some an attempt to break a regular hinged door or to break through the door, for instance. In sci-fi, they try to slide open or to stop a closing door, usually without success.

Or shoot the control panel, which for some inexplicable reason always releases the lock mechanism.

I meant you'd see the utility in being able to secure the doors while open, not that it's presently being done.

I also rewatched Aliens recently, and the amount of detail in the environment was amazing. The base had a believable presence of its own, instantly immersive. Ominous foreshadowing (captured facehuggers), swinging fluorescent lights (knocked down during battle), leaking ceilings, half-eaten donuts...

And before it was destroyed, people on the base looked "normal-weary", and talked in believable fashion. It looked functional, as opposed to being there "for the camera", like they do in modern films.

I don't know the exact reasoning behind it (although I guess it might have to do with certain restraints due to special statics and architecture of the complex), but the place where I work has several big sliding doors that should close in case of a fire, to prevent further spreading of the fire.
It was build in the 70s, afaik, and at least for some of the sliding doors a "normal" one would not work due to columns being in the way. That's not true for all of them, though.

IIRC the reason they had sliding doors in Star Trek etc. was because they were easy to make and looked futuristic. Honestly, you just needed a flat piece of painted wood, some rope, a few pulleys and a guy pulling it at the right time.

Of course and that's the point.

That reminds me: some ships, especially freighters and cruisers also have vertically sliding seal doors in lower levels, to contain fire and flooding but they are only for emergencies and are not operational for casual use. They are not automated for two-way operation either but only to seal and then reopen manually. I'm not sure if they can be called "doors" at all. They are emergency compartment seals.

I'd guess sliding doors are easier to make automated, based on the large variety of automatic sliding doors you see in day to day life, compared to hinged doors.

Perhaps. I'd rather say that sliding doors are tidier for everyday use, since you can hide the mechanism from exposure to environment and people, I guess.

Unless I'm mistaken, NASA/ESA/FKA/JAXA don't use any sliding doors, btw, though I don't know if any door or lid is automated there at all.

Automated doors always bothered me in sci-fi. In any kind of vehicle that moves in a hostile environment you want something that is simple and rugged. A normal hinged door with simple rotating mechanism to extend steel spokes to fix it in space while closed is perfect on so many levels I hardly think it could be improved with any high-tech gadgetry. I also think that in the navy all bulkhead doors must be closed at all times when not in use.

Gravity-operated shutters would work in a submarine or a surface ship, but would be useless in any kind of realistic spaceship. So any kind of emergency separators would have to be mechanically, hydraulically or explosively operated.

I fucking hate star trek and how it influenced the idea of a spaceship in peoples minds.

Especially if said door is made out of Futuranium and weighs 300 kilos.

Generally speaking, if a ship is travelling faster than light under it's own power, I tend to assume any sort of mechanical movement within the ship is utterly trivial as a matter of power usage and miniaturization of the mechanisms. The cost of a heavy sliding door on a space ship that moves faster than light is akin to the fuel efficiency cost of a radio antenna on a 16 wheeler.

The argument against such doors makes more sense for lower tech space ships and facilities like in Aliens though.

I'm all for sliding doors as they are the easiest to make in an isometric game. No opening animation required, just move the bitmap around.

You lazy fuck

Are the doors really a problem in a genre populated with such technology as photon based explosives, FTL matter transportation, self replicating nano technology and human-like AI?

It's not about technology. It's not about theoretical possibility. It's about existing depictions in popular culture and the problems with those depictions.

But ultimately, the concept of sliding door itself with large blocks of moving parts has little relevance to technology. The latter will determine the size and energy requirements. All the other points in my OP will still stand. If you need automated doors that don't restrict living/working space during operation, things like advanced shape memory alloys that could fold into and out of shape with seal bindings at a molecular level or shutter doors made out of super strong alloys or what have you, could make more sense.

Flexible material that can roll up into itself.

This is a problem? Seems more like you are just stating something you would do.

How so? If anything I would think it easier if a ship lost gravity. Float near the door and it opens vs. trying to work the lock mechanics of a hinged door while hanging upside down.

Yes.

If anything a normal door is much weaker. It has obvious hinge points for tampering. A sliding door is purely limited by the strength of whatever material the door is made of. Given that we are in the future, assume its some super-material that is impenetrable to any kind of small arms or impacts.

I believe this is the point of the failsafe "blow the controls and it auto opens/closes" thing. At most, have a backup mechanism and send someone to repair it during the offtime. It's also probably very, very rare that a door would be damage without the ship itself having serious damage, at which point you have bigger problems.

A maintenance area for each level is probably standard for most concepts. So you need something that's already there?

The same for everything else?

Your reply doesn't make sense. The context is popular culture depictions, not how stuff could actually fucking work or existing real-life applications.

I have automated sliding doors in a grocery store a block away - they are not fiction.