Bremen cog

The Bremen Cog at German Maritime Museum, 2002
History
Laid down:	1380s
Fate:	Sank while under construction, salvaged between 1962 and 1965, currently a museum ship
General characteristics
Class and type:	cog
Tonnage:	90 tons
Displacement:	55 tons
Length:	23.27 m
Beam:	7.62 m
Sail plan:	Square-rigged
Notes:	Dimensions taken from exhibition notes at the Hanseatic Museum in Bergen

Bremen cog or Bremer Kogge is a well-preserved wreck of a cog dated to 1380, found in 1962 in Bremen. Today it is displayed at the German Maritime Museum in Bremerhaven as one of the main features. Three nearly identical replicas of this cog have been built: Ubena von Bremen, Hansekogge and Roland von Bremen.

On 8 October 1962 wooden fragments of a ship were found in the Weser River during dredging operations. They turned out to be remnants of a cog that seems to have sunk during a storm flood after drifting away from a shipyard before completion. Until then cogs had only been known from medieval documents and seals. Based on the dendrochronological analysis of the oak timber from which the cog was built the ship was dated to about 1380 AD.

The large parts were measured, registered, and stored in water-basins in a pier-shed in Bremen to prevent the wood from drying and shrinking. A further search with the aid of a diving bell-ship in 1965 retrieved more than 2000 additional parts which also were stored. It was decided to exhibit it in the planned German Maritime Museum in Bremerhaven. In 1972 the Koggehalle had been completed and the parts were reassembled under constant sprinkling. Almost the complete starboard side and a third of the port side could be reconstructed. The construction then was encased in a tank to be impregnated in polyethylene glycol for 18 years. Finally it was cleared from the remnants and is on display since 2000, 25 years after the opening of the museum.

The Bremer cog had one mast and was square-rigged, with a carvel-built bottom and clinch-built sides. The rib timber was built in after the hull had been made. The cog was 24 m long, 8 m in the beam and just over 4 m high on the sides. These measurements would have produced an estimated load capacity of 130 tons. Other estimates put the cargo capacity at only 90 tons.