Another thread a few weeks ago brought up an often overlooked factor: the glassed-in wood shelf that supports the front of the bunk. It, not the hinge, carries the weight
. It was noted that undetected or neglected leaks
in the window can cause the wood to rot inside the fiberglass.
I'm unable to find/post that link right now, but it did have some good ideas re strengthening the bunk set-up. If you use the Google search for "Scamp bunk" it should show up.