It sounds like it was designed at the folding wingtip which makes sense
I am curious if any other aircraft might have had the Safety Wing Tip feature
The point of detachment was three feet in from the tip, had it been at the wing fold you would have had no ailerons, the wing fold was six feet inboard of the tip, not a feature of any other aircraft that I'm aware of.
You can read of test pilot Corky Meyer's testing of the wing tip feature in his book "Flight Journal", a disjointed account here.
https://books.google.com.au/books?id...20wing&f=false