Koch (boat)

The koch (коч) was a special type of small one or two mast wooden sailing ships designed and used in Russia for transpolar voyages in ice conditions of the Arctic seas, popular among the Pomors. Because of its additional skin-planking (called kotsa) and Arctic design of the body and the rudder, it could sail without being damaged in the waters full of ice blocks and ice floes. The koch was the unique ship of this class for several centuries. The development of koch began in the 11th century, when the White Sea shores began to be settled. This type of ship was in wide use during the heyday of Russian polar navigation in the 15th and 16th centuries. There is documentary proof that in those days the private Russian civil fleet in the Arctic seas numbered up to 7,400 small ships in a single year. In the 17th century, kochs were widely used on Siberian rivers during the Russian exploration and conquest of Siberia and the Far East. In 1715, during the Great Northern War, the Russian Arctic shipbuilding and navigation were undermined by the ukase (decree) of Tsar Peter the Great. According to the ukase, only novomanerniye ("new-mannered") vessels could be built, that is the civil ships, which could also be used for military purposes. The koch with its special anti-icebound features did not suit this aim. In the 19th century the anti-ice floe protective features of koch were adopted to the first modern icebreakers, and in fact koch may be regarded as the most ancient form of icebreaker, though wooden and relatively small. The koches were traditionally built shell-first, with overlapping planks, following the once-widespread Northern European clinker shipbuilding tradition. Iron rivets and brackets, as long as shrub branches or tree roots, were used to fasten the planks to each other. Ribs were inserted into the hull once the shell of planking was assembled. As these ships were in use as late as early 17th century, this may be by far the last use of the clinker technology on large sea-going vessels.