Koch (boat)

The koch (Russian: коч, IPA: [ˈkotɕ] ⓘ) 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.

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.

There invariably were the fore-part compartment used as the crew's quarters, the stern cabin for the captain, and the cargo hold amidships.

Special Arctic design features included the rounded lines of the ship's body below the water line, an additional belt of ice-floe resistant flush skin-planking (made of oak or larch) along the variable water-line, a false keel for on-ice portage (and for damage prevention from running aground in shallow waters), and the shaft-like upper part and wide lower part (below water-line) of the rudder.

Each iceboat had the cargo capacity of 1.5 to 2.0 metric tons (3,300 to 4,400 lb) and was equipped with long runners (5 to 7 m or 16 to 23 ft) for portage on ice.

Other tools and means of navigation were the detailed charts and sailing directions, the stars, and the pilot's marks on the familiar shores.

The first, a mixed classification, distinguishes between three subtypes of kochs depending on both their place of origin (Siberian and Mangazeyan) and their sea-worthiness (morskiye, that is "seafaring").

The second classification does not pay any attention to minor shipbuilding differences and divides all kochs into two categories according to the main spheres of their maritime operations: river/sea, and morskiye (seafaring) for long-range sea voyages.

The flat or rounded bottom made them maneuverable when dodging ice floes, but probably unstable in a severe storm.