For 600 years, the waters off Copenhagen have hidden an exceptional secret. Now, maritime archaeologists from the Viking Ship Museum in Denmark reveal the discovery of the world’s largest cog, a medieval cargo ship whose size and previously unknown construction details offer new insight into the maritime technology and trade networks of the Middle Ages, shedding light on the scale and organisation of medieval trade across Northern Europe.
The ship, named Svælget 2 (Svaelget 2) after the channel where it was found, measures approximately 28 metres long, 9 metres wide and 6 metres high, with an estimated cargo capacity of 300 tons. Built around 1410, the cog represents the largest example of its type ever discovered anywhere in the world.
According to the archaeologists, a ship of this size reflects a society in transition, because such a vessel required a well-established trade structure:
“A ship with such a large cargo capacity is part of a structured system where merchants knew there was a market for the goods they carried. Svælget 2 is a tangible example of how trade developed during the Middle Ages,” stresses Otto Uldum.
The cog was an efficient ship type that could be sailed by a remarkably small crew, even when heavily loaded. Large cogs were built to make the hazardous voyage around Skagen from what is now the Netherlands through the Sound and reaching the trading towns of the Baltic. Svælget 2 points directly to the extensive trade networks that bound Northern Europe together in the 15th century:
“It is clear evidence that everyday goods were traded. Shipbuilders went as big as possible to transport bulky cargo – salt, timber, bricks or basic food items,” says Otto Uldum.
The cog was the super ship of the Middle Ages. Developed in the North Sea region, it made it possible to transport large quantities of goods efficiently and at low cost. This ship type was central to economic development in the 14th and 15th centuries, and with its enormous cargo capacity, it transformed trade patterns. Where long-distance trade had previously been limited to luxury goods, everyday commodities could now be shipped across great distances.
“The cog revolutionised trade in Northern Europe. It made it possible to transport goods on a scale never seen before,” says Otto Uldum.
Read the full press release on the Viking Ship Museum website
