- Double rubber lip seal – In case of reduced weathertightness on cellular container vessels, some classes allow to use a joint between panels fitted with a double rubber lip seal preventing rain and spray from entering the hold.
- Swing-seals – Hydraulically- or manually-operated seals for weathertight non-sequential operation. The swing-seal comprises a foldable steel beam fitted with gaskets. In the sea-going condition, the beam seals the joint, and when the hatch is open in port the panels can be handled in any order. Folding of the sealing beam can be performed by hydraulic cylinders, or manually by a ratchet or pneumatic power tool.
