Lane Metres – Roll on-Roll off (Ro-Ro) ships have their cargo spaces divided into lanes in which vehicles will be stowed one behind the other. The total length of all the lanes in metres is used to describe the cargo capacity of the ship. TEU – Container ships are usually described in terms of the number of containers they can carry. The abbreviation ‘TEU’ stands for Twenty-foot Equivalent Unit and is the customary way of referring to a container ship’s size. Are just what the name implies, they show the main parts of the ship from a side view as well as from above for each deck. They usually include one or more cross sections, simplified general arrangement plans are used in some of the descriptions of ships which follow. The General arrangement plan will also indicate the features of the loadline and the vessels displacement scale – that is a scale showing the distance by which the vessel will sink into the water for each tonne loaded on board. Similar to General Arrangement plans but particularly showing full details of the hatches, cargo carrying spaces, bunker, ballast and fresh water tanks. Plans which are created as the ship is loaded to show where each parcel of cargo is placed in the vessel and the ports between which it is moving. The importance of stowage plans and their relationship to vessel stability is discussed later in the course. A basic knowledge of how ships are laid out will also assist in understanding the operational and commercial aspects of the business. Below is a simple conventional vessel with most of the important components marked. The hull comprises steel frames covered with steel plate. The hull is divided at intervals into compartments that are separated by watertight bulkheads. The first of these in the bow of the ship usually contains a water tank (forepeak tank) and a storage area (forecastle or fo’csle) because it is not a convenient shape for carrying cargo.