Ship Terminology and Structure
Ship Structure and Terminology
Deck Definitions
The main deck (or upper deck) is often exposed to the sea and weather, providing shelter for the vessel’s contents. The forecastle is the foremost part of the upper deck.
The tweendeck divides the vessel into separate holds. The tank top is the intermediate deck between the upper deck and the vessel’s bottom.
Upper holds and lower holds contain cargo. Hatches provide access to the holds. Spaces for liquid cargo are called tanks.
Peak tanks, located at the fore and aft ends of the vessel, store ballast water and absorb impact forces during collisions.
Compartments and Features
The chain locker, situated over the fore peak tank, stores the anchor chain. The boatswain’s (or bosun’s) locker, in the upper part of the fore peak tank, stores ropes, paint, and dunnage (stowage material).
Bulkheads are vertical separations between holds and spaces. The fore peak bulkhead and aft peak bulkhead are watertight, preventing flooding in case of collisions.
The engine room is a watertight space containing the propulsion plant. The steering engine room, also watertight, is often located over the aft peak tank.
The double bottom provides strength and storage for fuel, lubricating oil, fresh water, salt (ballast) water, and potable water. Cofferdams are empty spaces for separation; the longitudinal cofferdam runs fore to aft.
The superstructure, located on the main deck, houses crew and passenger accommodations, the mess room (dining area), the galley (kitchen), and the pantry. The master compass is usually situated on the monkey island, a small deck or platform above the wheelhouse.
Nautical Terms
- To hoist: Raising or lifting.
- Hawser: A thick rope or cable for towing or mooring.
- Fairlead: A guide for a mooring line through the bulwark.
- To berth (atracar): To bring a ship into its mooring place.
- Heaving line: A lightweight line with a weight, used to pull a heavier line.
- Fenders (defensa): Cushions to protect the ship from impact.
- Chock (“cuña”): A guide for a mooring line or towing wire.
- Bunkering: Supplying fuel to ships for their own use.
Ship Dimensions and Types
- Moulded breadth: Horizontal distance between the insides of the moulds.
- Moulded depth: Vertical distance between the insides of the moulds.
- Beam: Extreme breadth of the vessel.
Merchant Ships (vaixell mercant)
Vessels designed to transport cargo and/or passengers, including general cargoes, bulk cargoes, refrigerated cargoes, heavy cargoes, and timber.
- Liners: Carry cargo between fixed destinations on a prearranged schedule.
- Tramps: Carry cargo on non-fixed schedules.
Additional Terms
- Bulkheads: Vertical compartment separations.
- Decks: Horizontal separations.
- Upper deck: The imaginary line from bow to stern is called the fore-and-aft line.