I was looking at the DEO VOLENTE & OCEANIC (both are Hartman vessels) general arrangement plans & I'm wondering how are the tweendeck hatch covers are opened/closed/stacked. For first vessel I read that it's gantry hatch cover crane can handle both hatch covers & tweendeck covers, second vessel also uses it's gantry crane to do the same. And not just that, but same gantry crane can also rotate tweendeck covers on 90 degrees & stack one on another forming a bulkhead. I looked at gantry cranes for those 2 vessels on photos & how it's drawn on GA plans & by the looks of it, it can only handle the upper hatch covers. The crane's spreader has 4 hooks & connects to covers at their sides, it also can't change it's width. Yet the the hold is narrower than the spreader which can't be fully lowered to reach the tweendeck.
Also, from those ships' GA plans I think the tweendeck covers can only be stacked within the hold... or the same gantry crane can somehow lift them & stack on the upper deck?
Could someone shine a light on this?
Regards,
Denis