Plating of a Vessel

the watertight shell designed to provide the longitudinal and transverse strength and the buoyancy of a vessel. The plating either consists of a number of strips called strakes, which are made of materials such as steel sheets or wooden planks, or it is a continuous sheath of reinforced concrete or plastic. Plating strips are usually placed lengthwise or, less often, crosswise on a vessel’s hull. The longitudinal joints between strakes are called seams and the transverse joints are called butts. In steel vessels the sheets are welded to one another and to the framing; more rarely, they are riveted. In wooden vessels the planks are secured only to the framing, and the seams and butts between the planks are caulked.

The longitudinal strip of side plating at the upper deck is called a sheer strake, the plating at the junction between the side and the bottom is called a bilge strake, and the middle strip of bottom plating is called the keel strake. These three strips have a greater thickness and are built to higher specifications in materials and construction. The hull of vessels built for navigating through ice has a band of reinforced plating known as an ice strake at the waterline.

A ship may have have an inner shell plating in addition to the outer shell. The inner side plating and second bottom serve to increase the strength, safety, and operating advantages of a vessel and to reduce the chances of polluting the ocean if the vessel is damaged.