A Pushmi-pullyu in Middle Earth!?!
 

A Pushmi-pullyu, an animal in the Hugh Lofting's 'Doctor Dolittle' books, has the front sections of two animals connected at the middle. When it tries to move, it has trouble as both heads go in opposite directions, resulting in it going nowhere. This animal has yet to be seen in Middle Earth, even in the movie adaptations. That said, there is a reference to a different kind of 'push me - pull you' in the LotR. Where? Well, in the the Chamber of Mazarbul in Moria.

This has always bothered me. When the Fellowship is caught unawares by the orcs after 'Gandalf's story time,' the following is stated about the door between the company and the enemy:
Why is this not a good thing? I would think that a door opening inwards would be easier to hold closed. Sure, the enemy would have maybe an easier time pushing the door inward, but, using wedges as the Fellowship does, it would seem that this type of door swinging would be preferable to the defense than the other orientation.

How would one easily defend a door that pulled open?

So I think that Gandalf must have been just letting us know the layout of the room, and not making any negative comment about the door being a push me-pull you.

Actually I doubt it... Trying to ram an inwrad swinging door would be easier than and outward on also an inward swinging door requires defenders to back before going out will the outward hinders the attackers

I understand that one's fellows would have to step back as the door is being opened, but from the defenders' side, how would you keep the door closed?

The door opened inwards, and so if you wedge it, the wedges would become tighter the more the opposition pushed. Given the right circumstances, you could put something across the door (assuming you have something to hold the bar) to keep it closed as well.

Think that Boromir does this in Peter Jackson's movie.

Also, the door could be braced from the opposite wall, or using the tomb.

None of these methods work if the door opens outwards.

I don't know much about this subject, but I have seen that in some of the few medieval castles we have arround, that their main gates opened outwards. . . The door was then constructed so that you could blokade it. I guess it must give better resistance in case somebody tries to force the door open.

Precisely Alatar I hate to say it like this but if I had a castle and I saw you pulling o the door I wouldn't be worried they're barred and also locked usually reinforced not often you see people pulling on castle doorks unless its drawbridge style.

Much depends on the door mechanism and handles, doesn't it?

The door on the other end of the room, the one that Gandalf put a shutting spell on, had metal rings as door handles, which makes me assume the door in question did too. This should mean that there was no mechanism to keep the stone door closed unless the lock was turned, obviously a bad thing for the defenders. If the door opened outwards however, and they had metal bars, swords, spears or anything long enough, they would probably have been able to block the door by threading it/them through the iron ring and past or preferably across the doorpost. Then the door would have been very hard to open from the outside, as you can't get much force pulling on a handle, even if you are a cave troll, and able get your bulky fingers inside the ring. Who says that cave trolls have fingers anyway? Then don't have toes!

As the door did open inwards the attackers could apply a lot more force on it by ramming it. Unlike pulling on a handle, this can be a collective effort too, although I suppose the cave troll just kicked it in.

Yes. There are many factors that could influence the door's swinging. Like if I had a door that swung open, specifically designed to knock people off the narrow railless bridge that led to my castle, well, then, I might have one type of door in mind. If I could put something across the door from the inside that would make it virtually impossible to open, then I might consider a door that opened inward.

But we're discussing one door in Moria here, and have what's written, and can assume the rest (as long as it fits my argument :D).

That makes sense, though I thought that there wasn't much available on the door to secure it.

And I don't even want to go into how a troll walks without toes (did you ever know how important your big toe was? Not completely necessary, but surely a big help.)

That makes sense as well, though the defenders can jam it up more easily.