09.ship dimention

The ship dimensions, such as the ship breadth, depend on the number of containers placed abreast on deck and in the holds. Thus, one extra container box abreast in a given ship design involves an increased ship breadth of about 2.8 meters. The average loaded container weighs about 10-12 tons but, of course, this may vary, so the modern container vessels are dimensioned for 12-14 dwt per TEU.

Containership capacity is normally expressed in Twenty-foot Equivalent Units (TEU), which is defined as the number of 20' x 8' x 8'6" containers it can carry; or, similarly, in Forty-foot Equivalent Units. Containerships vary considerably in size. Some of those serving major ports have capacities exceeding 5,000 TEU. Some recently built for feeder service (i.e., serving small outports from a major port) have capacities of 400 TEU or less.The delivery in 1980 of the 4,100 teu Neptune Garnet was the largest container ship to date. Deliveries had now reached a level of 60-70 ships per year and, with some minor fluctuations, it stayed at this level until 1994, which saw the delivery of 143 ships. With the American New York, delivered in 1984, container ship size passed 4,600 teu. For the next 12 years, the max. container ship size was 4,500-5,000 teu (mainly because of the limitation on breadth and length imposed by the Panama Canal). The hull dimensions of the largest container ships, the so-called Panamax-size vessels, were limited by the length and breadth of the lock chambers of the Panama Canal, i.e. a max. ship breadth (beam) of 32.3 m, a max. overall ship length of 294.1 m (965 ft), and a max. draught of 12.0 m (39.5 ft). Panama Canal lock chambers are 305 m long and 33.5 m wide, and the largest depth of the canal is 12.5-13.7 m. The canal is about 86 km long, and passage takes eight hours. The corresponding cargo capacity was between 4,500 and 5,000 teu. These maximum ship dimensions are also valid for passenger ships, but for other ships the maximum length is 289.6 m (950 ft). However, it should be noted that, for example, for bulk carriers and tankers, the term Panamax-size is defined as 32.2/32.3 m (106 ft) breadth, 228.6 m (750 ft) overall length, and no more than 12.0 m (39.5 ft) draught. The reason for the smaller length used for these ship types is that a large part of the world's harbors and corresponding facilities are based on this length. At present the canal has two lanes, but a possible third lane with an increased lock chamber size is under consideration in order to capture the next generation of container ships of up to about 12,000 teu.