I noticed that elevator doors are always narrower than the compartment, so people get jammed up trying to exit.

Why don't they just design elevator doors so they are wide enough for everyone to exit comfortably?

closed as off-topic by Izhaki, Graham Herrli, Charles Wesley, msp, JonW Apr 7 '15 at 7:06

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  • 6
    This is an engineering question. The design choices are guided by the physical restraints of the system. – Evil Closet Monkey Mar 30 '15 at 4:14

A typical passenger elevator's doors, even when opened, must fit in the elevator shaft. Unless each side of the door is split into multiple sections, that means that the doors can be at most half the width of the car. If the doors are split in half, that allows a width up to 2/3 of the car width. If they're split in thirds, that allows a width up to 3/4 of the car width.

Freight elevator doors are usually the full width of the car, but to allow the height to be more than half the distance between floors it is necessary that the distance the doors travel be less than the distance between them. This is generally accomplished by having the doors split into upward-moving and downward-moving portions. That allows the same part of the shaft to house the bottom half of third floor door when it's open as would house the top half of the second-floor door when it's open. Having the doors split into parts that move up and down also means that each half of the door serves as a counterweight for the other. Unfortunately, while manually-operated doors which move up to close are reasonably safe, doors which rise from the floor automatically would pose a tripping hazard. Most passenger elevators need to be designed so that they won't be disabled if someone leaves without closing the doors, but freight elevators don't have that limitation.


Because the doors need double the space of the compartment to open, they need to go somewhere you know... so if an engineer decided to use that extra space needed for the door to open, as space for the compartment, someone would ask: why is the door narrower than the compartment? :)

PS. I don't know about you but the elevators I've been using have doors to match the compartment (which is already small).

  • 1
    "someone would ask: why is the door narrower than the compartment?" - I think the premise of the OP is that the door is narrower than the compartment (e.g. like here, here, or here. – O. R. Mapper Mar 29 '15 at 10:04

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