Bolted plates for removal of machinery may be fitted.
Such plates shall be insulated to A-60 class standard.
Signboards giving instruction that the plates shall be kept closed unless the ship is gas-free, shall be posted on board.
Wheelhouse windows may be non-fixed and wheelhouse doors may be located within the above limits as long as they are so designed that a rapid and efficient gas and vapour tightening of the wheelhouse can be ensured.
Windows and side scuttles shall be of the fixed (non-opening) type.
Such windows and side scuttles except wheelhouse windows, shall be constructed to A-60 class standard.
