The Cog - A Cargo-carrying Vessel of the Middle Ages

The cog was a single-masted ship with a square sail and a stern rudder. The cogs had a length between 15 and 25 metres, a width of 5-8 metres and a side height of 3-5 metres. The loading capacity of the cogs is measured in "loads". Originally, this was the amount of rye that a team of four horses could transport (approx. 2 tons). Large cogs could be loaded with up to 100 loads, i.e. approx. 200 tons.

First listed in 948 in ship's entries from Muiden near Amsterdam, the cog was the Hanseatic League's "common ship" for over 200 years during the 13th and 14th centuries. It was the characteristic cargo-carrying vessel of the Hanseatic economic association - the "transporter of mass goods" - according to the standard of that period. Its main sailing areas were the Baltic Sea and the North Sea. It was possible, with the help of cogs, to secure the expanding exchange of raw materials, foodstuffs and handicraft products. The striving town of Hamburg with its harbour and the type of ship known as the cog are inseparably joined together.

The transport container of the Middle Ages was the barrel. Not just liquids were transported in barrels; they also contained herrings as well as knives, metal bars or also lumps of ore.

The measurements of a part of a cog seen here in reproduction are based on a wreck found in a harbour basin in Bremen in 1962. The characteristic features of this type of ship have been reproduced here in almost normal size. Originally, the ship's hull was made of wide oak planks which were nailed to each other, built up in layered structures and caulked from within. The ribs (cross-ribs) were chopped from crookedly grown timber, inserted later and joined to the outer skin by means of oak dowels. The only superstructure that the cog had was a castle on the stern with a large winch.

Technical data of a cog:

Length: between 15 and 25 m
Width: about 5-8 m
Side height: between 3-5 m
Length of mast: approx. 25 m
Area of the sails: approx. 200.00 m2
Loading capacity: approx. 150.00 m3
Draught when loaded: approx. 2.25 m*
Crew: 10-18 men

Characteristic features:

open deck
caravel planking (touching each other on the sides) on the flat area of the floor, which then merges into a clinker planking on the side walls.
strong crossbeams (edge length about 40 cm), the ends of which jut out from the ship's side.
two-part, towering stem and stern frame
a rudder, attached to the stern frame
the inner caulking of the clinker planks

- From a Saxon Village to a Fortified Mission and Trading Post
- Ecclesiastical Hamburg
- Hamburg as a Hanseatic City
- The Cog - A Cargo-carrying Vessel of the Middle Ages