Piggy-back hatch covers for minimised rolling cover stowage space
For open hatch bulk carriers (OHBC’s), rolling covers of the Piggy-back type are preferred as the deck allows little or no free space for stowing the covers when the hatches are open.
This system always comprises two panels, with one panel being raised high enough for the other to roll underneath and to support the lifted panel on to its ‘back’. Both panels can then be rolled back and forth.
The system can either be applied to a pair of hatches or to the two panels of a single hatch. If the number of panels exceeds two, the system is called ‘stacking’, and special high lifters are needed.