The attached is a photo of a HMS Bounty hold door from the Anatomy series book.
On initial examination of the door, It looked like the top section had a series of vertical iron bars fitted. A close-up reveals something not so straightforward, but I am at a loss to identify. Any ideas?
(The photo is on its side. Could not figure out how to rotate it.)

On initial examination of the door, It looked like the top section had a series of vertical iron bars fitted. A close-up reveals something not so straightforward, but I am at a loss to identify. Any ideas?
(The photo is on its side. Could not figure out how to rotate it.)
