Independence Hall Key and Lock

[BillB]

I just got back from a trip to Philadelphia. Here's a photo of the key and lock to Independence Hall. I was told that the key could open the door with a double turn from inside and outside. However, when we tried from the outside, the key could not be fully inserted, being blocked by the stop ring which aligned it when opening from the inside. The folks could not explain how it worked. I'm guessing that the stop ring could be adjusted (rotated?), possibly with fingers or a metal instrument. Anyone familiar with how this system might work? Anyone have measurements of the door, lock, and key?


The key is approximately 7.5 inches long, as is Mount Vernon's Bastille Key. The shoulder is 2 and 3/8 inches from the end of the pin and is 3/16 inches wide. Based upon my marked pen gently stuck into the hole, from the inside of the door, the stop is approximately 3 and 1/4 inches in from the lock surface; from the outside of the door, the stop is approximately 1 and 5/8 inches in from the escutcheon. Unfortunately, I was in a rush and didn't bring my list of measurements to be made and the appropriate tools with me. I am also attaching a view of the entrance area which was undergoing some repair. As well, I'd like to estimate the thickness of the door and the size of the lock. Thanks for comments!