Usually driving methods for a Side Rolling hatch cover are either rack and pinion type or chain driven type using the power generated by shipboard hydraulic system.
Rack and pinion type; Covers are sliding on a pair of rack located transversely at the underside of panels. A hydraulically operated pinion drive is positioned on the outside of the side coaming which is engaged in the rack.
When two panels are fitted, each own rack and pinion drive system allows independent operation.
Chain driven type; this system are available including a hydraulic motor driven chain drive arrangement that opens both the panels of a hatch cover simultaneously.