Crane Hinges

VaultDoors

Do large vault doors with pressure bars in front or in back of the crane hinge have a wide range of motion like the this Fort Knox vault door?

[video=youtube;utGGS5mte_Q][/video]

The Fort Knox door has no pressure bar so nothing prevents the door from pivoting almost 360 degrees but the only doors I have seen pivot greatly on crane hinges are emergency doors. Pressure bars on large vault doors detach on the non-hinge side but appear to be fastened on the hinge side which would restrict the door from pivoting to only a few degrees - which may be all that is needed for the door to be pushed in straight. It seems that doors with pressure bars behind the crane hinge would have a wider range of motion than doors with pressure bars in front of the crane hinge. Does anyone know the typical range that large vault doors with pressure bars are able to pivot on the crane hinge when fully opened?

Gary Stephenson

That seems to be a weird crane hinge design that is just for show rather than doing what a crane hinge is designed to do, allow the door to enter the frame more squarely thus making it possible to minimise door/frame gaps.

VaultDoors

Agreed, the video only serves to illustrate the range of motion a vault door can achieve without a pressure system restricting it. Vault Structures, Inc. makes a round vault door with a real crane hinge without pressure bars which I assume can pivot almost 360 degrees (less the thickness of the crane hinge) when fully opened. Unrestricted access to the front of a vault door may be desirable for maintenance. Not sure why there is a pressure wheel on the front, perhaps the pressure system is internal?

wylk

VaultDoors wrote
… Not sure why there is a pressure wheel on the front, perhaps the pressure system is internal?

If I understand the door from images, the small hand wheel causes the 24 bolts to retract/extend by rotating the ring that attaches to the “tie rods.” The larger hand wheel engages/disengages four tabs that prevent/allow that ring to rotate. In other words, the small hand wheel locks the door into the frame and the large hand wheel locks that mechanism in place.

I don’t see anything like a pressure system.

Here are some images of the Vault Structures boltwork:

[unknown]

Huw Eastwood

Have to agree with Gary on that Fort Knox crane hinge. The video certainly gave me a good laugh, his opening sentence alone started me off, but the “heavy duty 2S crane hinge” followed by “full rotation articulating door” saw me on the floor.

Regards the boltwork sequence for the Vault Structures round door its actually described in the link that you posted, under Specifications on the right hand side of the page.

wylk

I’m having trouble imagining a case where such extreme door rotation has any advantage.

Even the small movement allowed on large traditional doors could be dangerous. Witness the case of the Cincinnati Fed door clipping off one of its combo dials.

Chubby

That “distressed” door is about as nasty and phoney a piece of kit as I have ever seen.

Huntlocks

Agreed, looked cheap and nasty.