Folding type hatch cover is operated by external hydraulic cylinders acting directly in such a way as to ensure safe and correct operation of the panels.
When, from the closed position of covers, the cylinders push up the end of the panel, the section of cover is folded and trailing panel, fitted with wheels, rolls on the rails to the stowage position, within the pre-designed space which is minimum.
The hatch covers consisting of 2+2 covers and both folding pairs can be operated separately and individually (non-sequential and partial).
The panels are provided with manual and automatic cleat system which secures the panel when closed. And the panels usually secured in the open position by using semi-automatic securing devices.