Initially, the typical vessel in service on the Atlantic coast was the “long boat”, the Viking knorr whose appearance seems to have sown terror in the 9th century, and enabled the Normands to colonize Iceland and Greenland. This is a light boat, easily pulled onto the beach. In the 11th century quite a different type of boat appeared, one of much greater capacity: the cog. The expansion of commerce and the development of more protected harbors led to this evolution in boats. The newer, heavier vessel cannot be hauled up onto the dry beach. Therefore it is not necessary for it to have a flat bottom, and consequently its hull evolves toward a round form with a keel. This keel also gives the ship much better nautical performance, since it drifts less in a crosswind. The boat is equipped with an axial rudder. This device was known in China since the 1st century AD, but it was possibly invented independently on the Atlantic coast of Europe, where the greater freeboard makes it difficult to use the ancient rudder-oar. As was the case for the earlier boats, the cog has a single and very large sail rigged on a yard. The sail area could be increased in light weather by the addition of small sails attached to the edge of the mainsail or reduced in heavy weather using reefing straps sewn into the sail.
These new boats could attain capacities of 200 tons, even 300 tons in the 13th centu-
ry. On the Mediterranean Sea, ships having two or three masts and lateen rigging are
used by Italian mercantile cities.
Sheltered embayments progressively become ports with wooden quays, especially starting in the middle of the 13th century. Notable among these are Caen and Rouen in Normandy, developed by William the Conqueror; Genoa, Pisa, Venice, Amalfi,
29 Gies and Gies (1994), pp. 154-158.
Barcelona in the Mediterranean; La Rochelle, Boulogne, Dunkirk, and the cities of Flanders and of northern Germany, linked to the sea by channelized rivers often with outer harbors such as Nieuport for Ypres. In 1169 navigation is made much safer by the widespread adoption of the magnetic compass from China, and by the advent of navigation buoys and markers, and even beacons — fires burning on towers. But for the most part navigation does not continue through the winter months between December and March, as had been the practice since ancient times.
Navigation markers are set on shoals to warn of danger or mark an access channel. Often made of wood, they proliferate around the ports of the English Channel and the North Sea, as well as in the Mediterranean. For example the turret of Meloria was built of cut stone in 1157 in the mouth of the Arno River at the port of Pisa. Lighted beacons had already existed during the time of the Roman Empire, and were not entirely forgotten in the Middle Ages. Indeed in 810 Charlemagne had the Tower of Order of Boulogne, originally constructed in 40 AD by the Romans, rebuilt and illuminated. But this development of aids to nighttime navigation accelerates in the 13th and 14th centuries, as shown in table 9.1. However not all of these beacons are permanently illuminated, for wood is an expensive commodity.
Table 9.1 Lighted beacons between the 12th and 16th centuries (after Fichou, Le Henaff, Mevel, 1999)