Record Tower Floor, Dublin Castle

I’m quite new to this site but am enjoying reading lots of previous posts.

The cantilevered floor of the Record Tower at Dublin Castle (currently closed to the public pending remedial works) has me stumped. It appears to be supported from the wall but when you look at the pattern of the individual stones many don’t meet the wall but meet other stones which do (I hope that makes sense). I’ll attach some pictures if I can.

What I really want to know is does anybody have any idea of how the floor is held up?
(the green steel brackets were added in the late 80’s/90’s “just in case”)