Tuesday, May 27, 2008

Lovely Locks

I was completely taken with these locks from the height of the Republic of Ragusa, of which Dubrovnik was the capital. For many hundreds of years this small and wealthy maritime city-state held its own against the Venetians on the North and the Ottoman Empire on the East and South. Their maritime prowess was surprising, given their size and their small population; they were one of Venice's biggest competitors in sea trade; the Ottomans saw them as an important port, and treated with them accordingly.

And so, of course, they needed good trunks to lock up their valuables.

These are a few of the trunks I saw at the Rector's Palace in Dubrovnik. The lock mechanisms fascinated me, because they seem to use curved levers to shift movement from vertical to horizontal, and vice versa. Enjoy.

This one uses steel arcs to shift movement around the surface of the lid, opening or releasing the bolts into the locks, which are on the walls of the trunk. ( I have a picture of this but haven't been able to find it - I'll keep looking). I spent about half an hour staring at this, following the mechanism. It's superb.

This lock uses a snake motif to distract you from understanding the mechanism. I itched to play around with it to find out how it worked; but alas, there was an attentive docent...


spacedlaw said...

The mechanisms are so ornate that they look like some tpe of calligraphy.

Anonymous said...

There are two kinds of curved pieces in the first mechanism, so I'm not sure which ones you're referring to as "arcs," but neither kind appears to serve as a lever.

The first kind is the kind that looks something like a fish; those seem to be mainly decorative except that the "mouth" end serves to hold one of the straight moving bars.

The other kind of curved piece is more of a spiral; those appear to be springs.

Changes in the direction of motion from vertical to horizontal and vice-versa are accomplished with the L-shaped pieces. For example, the L-shaped piece attached to the bolt on the right side of the lid retracts that bolt (pulling it leftward) when the vertical bar attached to the rightmost bolt on the top edge moves downward. The springs serve as the return mechanisms for all of the L-shaped levers.

The second box, with the snakes, appears to work similarly; if you look closely you can see the same L-shaped pieces (and some V-shaped pieces in the corners.) You can also see some springs that serve as return mechanisms here. In this mechanism, they look more like modern springs, coiling several times around their attachment points.

Heather McDougal said...

I'm glad to see that you are looking at the pictures so closely! It means you are as fascinated as I am.

Actually the curved pieces that look like fish are not decorative. I looked closely at it as well, thinking the same at first, but they serve to guide the other pieces' movements so that they pivot while moving downward or to the side, enhancing their effectiveness.

Wonderful things, though, eh?

Anonymous said...

Yeah, I didn't express myself very well when I said that about the fish pieces. They are indeed guides for the straight moving bars. And I am indeed quite fascinated by them. I want to play with them and see all of the bits move.

Something I noticed about both designs that might not be immediately apparent on first glance is that the mechanisms appear to be designed to allow the chest to be closed and locked without access to the key. If you pushed in on any of the bolts, they would move, and the associated L-shaped pieces would move, but the pieces that push on the L-shaped pieces would not move. That seems to be why there are so many springs; there's one for each bolt.

Assuming the lock is a simple warded one, it doesn't seem that it's possible to unlock this chest and leave it unlocked. All of the springs would also serve to push the lock back to the locked position.

Unknown said...

Whoever made this lock is really a genius! Unlocking this seems difficult than decrypting an online account that has the strongest password combination. I bet that the only person who is able to understand the mechanism is the locksmith.

Rachelle Suezo