There is a drawing which suggests there is such said rig but the issue is it would prevent the bulwark from lowering
Not necessarily. At a guess I'd say it was attached to the deck, inboard of the railing, which would allow the bulwarks to be opened.
Alternatively it could have been attached aft of the bulwark. Not exactly optimal, but not unheard of either.
“Close” only counts with horseshoes, hand grenades, and tactical nuclear weapons.
That which does not kill me has made a grave tactical error
Source Materiel is always welcome.