Yes, I'm aware that tweendeck covers can be simply handled by own cranes & stacked where needed (I saw many photos with cargo vessels having their tweendeck covers stacked in front of the superstructure & the hold is fully closed by hatch covers), but in the DEO VOLENTE brochure it says:
An electro-hydraulic Rodenstaal traveling hatch cover crane is used to handle and transport the pontoon hatch covers which can then be stacked up to a maximum height of covers. The same traveling crane can be used for moving and setting up the two transportable grain bulkheads fitted for bulk cargo stowing purposes that can be slotted at several positions in each hold.
Both hatch covers and tweendeck hatches are handled by an electric hydraulic driven gantry crane.
So I wonder how...