The bulwarks (or, less commonly waist) of a vessel are protective structures built on top of the deck to prevent persons or cargo from falling overboard. Railings are often included as bulwarks, though when both are present, bulwarks may be used to refer to the built sections only (this article assumes the latter, see also railings).
Bulwarks consist of:
- Exterior Sheathing: Plate which forms the face of the bulwarks.
- Stanchions: Vertical supports, spaced every 1-3 frame spaces. Support the sheathing.
- Top Cap: Horizontal surface on top of the bulwarks, sometimes of traditional wood.
- Freeing Ports: Openings in the bulwarks which allow green water to escape.
- Scuppers: Freeing ports fitted with gates, to limit ingress of water from seas.
- Chocks: Openings in the bulwark, fitted with rollers or round pipe, to permit the passage of mooring lines or similar.
- Interior Sheathing: On vessels which work over the bulwarks, the inside is sometimes fitted with an inner plating to prevent snags.
- Screens - Raised section of bulwarks for protection, concealment or visual appeal
The height ranges from aproximately 900mm to 1200mm. Bulwarks through the bow tend to follow the flare of the hull, however further aft, it is common to see bulwarks inset from the shell plating, or with some tumblehome.