Bilge keels are added to the outside of the land on which the boat would lie on a hard surface to stiffen it and protect it from wear. The thwart risings are fastened through the timbers with its upper edge on the level of the undersides of the thwarts. With the timbers all fitted, longitudinal members are bent in. Sometimes the timbers in larger craft were also joggled before being steamed in.
in Scandinavia, in Thames skiffs, and larger working craft like the coble, sawn frames are used, assembled from floors and top timbers, joggled to fit the lands. As the timbers are bent in, they are copper riveted to the shell, through the lands of the planking. Elm species are not durable where the boat is used frequently in fresh water. Once the shell of planking is assembled, transverse battens of oak, ash or elm, called timbers are steam-bent to fit the internal, concave side. Gripes are used to hold the new strake in position on the preceding one before the fastening is done. Before the next plank is laid up, the face of the land on the lower strake is bevelled to suit the angle at which the next strake will lie in relation with it. This means that the boat's passage through the water will not tend to lift the ends of the planking away from the stem. This allows the end of the strake to be screwed to the apron with the outside of the planking mutually flush at that point and flush with the stem. That is, in each case, the land of the lower strake is tapered to a feather edge at the end of the strake where it meets the stem or stern-post.
At the stem and, in a double-ended boat, the sternpost, geralds are formed. From the hog, the garboard, bottom, bilge, topside and sheer strakes are planked up, held together along their ‘lands’ – the areas of overlap between neighbouring strakes – by copper rivets. In normal practice, this will be the same way up as they will be in use. In building a simple pulling boat, the keel, hog, stem, apron, deadwoods, sternpost and perhaps transom are assembled and securely set up. Clinker-built ships were a trademark of Nordic navigation throughout the Middle Ages, particularly of the longships of the Viking raiders and the trading cogs of the Hanseatic League.Ī comparison of clinker and carvel building styles. 320 AD, is the oldest preserved clinker-built boat. The oldest evidence for a clinker-built vessel, dendrochronologically dated to 190 AD, are boat fragments which were found in recent excavations at the site of the Nydam Boat. Overlapping seams already appear in the 4th century BC Hjortspring boat. The technique of clinker developed in the Nordic shipbuilding tradition as distinct from the Mediterranean mortise and tenon planking technique which was introduced to the provinces of the north in the wake of Roman expansion. 4 Comparison between clinker and carvelįrom clinch, or clench, a common Germanic word, meaning “to fasten together”.3.1 Fastening the centre-line structure.