The Clinker was another name for the Cog (In French and English), Kogghe (in Batavian), Koggen (in German) or "Coque", from the Spanish Coca or Cocha, or Concha in Latin, Coccha in Venetian. This was typical of the versatile cargo ships of northern Europe between the early Middle Ages and the era of great discoveries, although this type later coincided with the nava, more typical of the Lateen-rigged cargo ships. The clinker kogge was the first and most emblematic of these northern ships.
It was not created as an imitation of the nava but rather a derivative of the Scandinavian cargo ships, lined with clinkers, while in the Mediterranean freeboard construction, as in the past, Predominated. The Kogge was above all a functional, very large and belly-ish cargo ship: 3 to 1 ratio, rarely more than 30 meters long and 150 tons. She possessed only one mast, but in the fifteenth century two or three, before turning into a carrack.
Classical kogges primarily used primarily in the Baltic by the rich merchant cities of the Hanseatic League united in 1241, were built in oak with ash couples, and with a deck clearing a large hold. Their slowness was to be Compensated by better management of the hold, well-closed bilge panels to avoid flooding, and a single sail. The small bow mast, served only to to suspend a small square sail for harbour duties. The hull was often reinforced by transverse beams, like those showed here.
Quickly adopted by the British who also produced a local version of the nava, the Roundhip Cog had a raised platform for archers and a small front forehead almost always rectangular. The stern post was almost straight, supporting a large rudder with straight bar, the transverse lever system only appearing much later. The hull was quickly adopted in the Mediterranean, with local constructions, such as the freeboard, and a rounded bow instead of right. In fact they were almost identical to the naves. This ship dominated trade waterways for three centuries as an all-purpose do-it-all ship, evolving by first adopting a mizzen carrying a Lateen sail on the quarter-deck and then a short bowsprit carrying a small square sail. From the Clinker derives the Hulk, and then the carrack, the classical XV-XVIth Cent. large northern ship.
< Left: Picture of a rudder (wikipedia)