History Main / SlowDoors

If they close downward, expect this to turn into the IndyHatRoll SubTrope. Otherwise, people will jump or squeeze through whatever gap is still left when they reach the door, [[JustInTime which is conveniently ''just'' wide enough]].

If they close downward, expect this to turn into the SubTrope, IndyHatRoll. Otherwise, people will jump or squeeze through whatever gap is still left when they reach the door, [[JustInTime which is conveniently just wide enough]].

So, you're running towards a top-secret facility with heavily armed bad guys in hot pursuit. Or you learn that an airstrike or AlienInvasion is inbound. You need to initiate {{Lockdown}}! Fortunately, the first thing you did when you was install [[BigDoor huge, nearly impenetrable blast doors]]. Once they're closed, nothing can go through. You run in, press the BigRedButton marked '

* Averted in ''Film/JurassicWorldFallenKingdom'' when Claire Dearing and Franklin Webb are trapped in a control bunker when a malfunction causes the doors to shut before they can reach them. They're so focused on getting the doors open again they fail to notice the fire ladder leading to a hatch in the roof, until a dinosaur forces them to look for another exit.

* The alien mother ship in ''Film/IndependenceDay'' had a single triangular access opening that slowly closed after the heroes fired their nuke into the center of the ship. Naturally their spaceship managed to squeeze through while the pursuers all smashed into the closed door.
** In this case it's definitely justified as being slow as said doors are HUGE!

* Zigzagged in Literature/TheMurderbotDiaries novella ''Exit Strategy''. Murderbot and Dr. Mensah are trying to sneak out through the space station docks to their shuttle, when someone puts the docks into LockDown. At first the trope looks like it will be played straight as only air barriers go up, designed to hold in the atmosphere against decompression, but you can force your way through them. Then metal security barriers come up just before they reach the entrance. Murderbot is able to convince the dock supervisor to raise the barrier enough to let Mensah escape, [[WhatMeasureIsANonHuman but not himself]].

* Averted in ''Film/TheAtomicSubmarine'' (1960). A sailor tries to flee an alien spacecraft through a DilatingDoor as it slowly closes, but he's not quick enough and gets his arm caught and crushed.

So, you're running towards a top-secret facility with heavily armed bad guys in hot pursuit. Or you learn that an airstrike or AlienInvasion is inbound. Fortunately, the first thing you did when you was install [[BigDoor huge, nearly impenetrable blast doors]]. Once they're closed, nothing can go through. You run in, press the BigRedButton marked '

So, you're running towards a top-secret facility with heavily armed bad guys in hot pursuit. Or you learn that an airstrike or AlienInvasion is inbound. Fortunately, the first thing you did when you was install nearly impenetrable blast doors. Once they're closed, nothing can go through. You run in, press the BigRedButton marked '

Fictional blast doors may be on heavy hinges or they may drop or roll down down into position. In science fiction, some blast doors use an iris-like design which creates a progressively smaller circle as it closes.

So, you're running a top-secret facility with heavily armed bad guys in hot pursuit. Fortunately, the first thing you did when you was install nearly impenetrable blast doors. Once they're closed, nothing can go through. You run in, press the BigRedButton marked '
"emergency Blast Doors close" and...

There are some RealLife examples that lend this trope some credibility. Of course, the armored doors are gonna need to be heavy and strong for protection. The watertight doors on the RMS ''Titanic'' closed very slowly, with only the last foot or so dropping quickly, in order that personnel could escape the sections that were closed off alive. Some rather large and heavy doors also use high-torque hydraulics or electric motors to raise and lower, which are notoriously slow, having traded off speed for strength.

"emergency close" and...

So, you're running a top-secret facility, and the first thing you did was install nearly impenetrable blast doors. Once they're closed, nothing can go through.

There is only one flaw: they take time to close. ''Way'' too much time. Sometimes it seems that the "message" to close the doors takes its time to get to all of them as well; Door #1 will start to close, then sometime after that Door #2 will start to close, then Door #3 etc.

There are some real life examples that lend this trope some credibility. Of course, the doors are gonna need to be heavy and strong for protection. The water-tight doors on the RMS ''Titanic'' closed very slowly, with only the last foot or so dropping quickly, in order that personnel could escape the sections closed off alive. Some rather large and heavy doors also use high-torque hydraulics or electric motors to raise and lower, which are notoriously slow, having traded off speed for strength.

If this is done with vehicles and the escapee is being pursued, expect the pursuers to be unable to stop in time and crash into the blast doors.

* Averted in chapter 18 of ''Manga/{{Blattodea}}''. Alice lures Hanakamakiri into getting smashed by a blast door she had hacked into. The gate drops instantly with a large shockwave on impact, but despite leaving him trapped between it and the floor it seems to not have injured him at all.

* Averted in ''Film/{{Dredd}}''. When Peach Trees goes into LockDown, a nuclear blast door comes down on top of a BeggarWithASignboard before [[DeathByLookingUp he can do more than look up]]. The blast doors at the very top of the megastructure's air shaft close more slowly, but no-one can exit through them anyway.

* Averted in ''Film/{{Dredd}}''. When Peach Trees goes into LockDown, a nuclear blast door comes down on top of a BeggarWithASignboard before [[DeathByLookingUp he can do more than look up]].

-->-- '''Buster''', ''Fanfic/Plan7Of9FromOuterSpace''