= The Holk (Germna: Holk) =
In the 15. century the reliable Cog became increasingly replaced by the Holk. The naming as well as the form can be traced back into the pre-hanseatic Flanders as with the Cog. Then the Holk sailed predominantly between the western european continent and England. It was a single masted clinker built ship. Through many English and Dutch seals the development from the simple bananaform like clinker ship to a ship with keel and stem can be traced. Based on the change of the length width ration from 3:1 for the Cog to 4:1 on a massive keel with stem the dimensions increased. As this also impacted the castell the Holk became a strong and spacious transport ship. Until the middle of the 15th century the Holk could carry between 100 and 150 bales.
[c]The Holk in its late form[c]
Due to the upgrading to 120 bales capacity and the transition carvel like ship building the regging became more and more difficult.  The necessary oversized sail proved to be difficult to control even in good weather. Through the use of three masts the surface of a single sail could be reduced. Probably the carvel built Holk was the first to carry three masts. After this structural form had been established the castells were reinforced to carry additional weapons and fighter. The crow's nest was replaced by a top on the main mast. Later on the other masts were also equipped with this biggertop castels, that could carry several marksmen. Long lasting siezure conflics and hence resulting the necessity for convoys required these changes. The shipwrights fulfilled this requirement by the construction of these top ships, which antedate the development of warships. More artillery could then be loaded onto the ship.
Source: Günter Krause, Handelsschifffahrt der Hanse, 2010,  S. 135 ff.