Unusual double-arm boltwork

[wylk]

I found an image of a postcard that shows a large round vault door with unusual boltwork. It has two arms for each bolt, which I haven't seen before. Any guesses as to the maker?



I have tried to research the German American Trust and Savings Bank in Los Angeles. Sometimes old banking magazines will describe details such as who constructed the vault, but not in this case. The building is now condominiums.

The boltwork is vaguely reminiscent of certain Herring Hall Marvin doors, which used only one arm per bolt. This looks like a solution in search of a problem :-).

[Tom Gordon]

Perhaps only one arm was activated which would then cause the other end of the bolt to move around the circumference of the door instead of shoot outwards - it looks like that on the edge of the door.

[wylk]

My thought was that like the HHM doors, there is a circular plate that rotates but here there are two plates and each rotates in the opposite direction, each taking an arm in opposite directions, withdrawing its bolt. Assuming this door is unlocked and bolts withdrawn, then when locked both arms would come together and be positioned radially (which also gives it the best strength against an unlikely sideways attack).

I also wonder if they found their shortest employee for the photograph!