164 ruthy gertwagen
ships used “frame-based” Mediterranean technology. The cog’s features were not
simultaneously adopted in the whole Mediterranean. Genoese notarial acts of 1286
and 1292 were the first to mention the cocha which transported alum from Phocaea
to northern Europe. This evidence pre-dates what is traditionally taken as the first
reference to the cocha’s actual use in the Mediterranean in 1302–1312. It should be
noted that northern cogs appeared in the Mediterranean for the first time with the
Crusader fleets in 1217. After 1340, the Genoese replaced all their great merchant
galleys sailing to Flanders and England with coche. A decade earlier, the coche replaced
the Genoese buzius naves in the Mediterranean. In Catalonia the cog replaced the
navis towards 1380, then disappeared for 60 years, after which it became very com-
mon until the end of the sixteenth century. In Venice, although first introduced in
1310, the cocha only became dominant from the last quarter of the fourteenth
century. It is hard to explain why the process of adoption of the cocha was uneven
across the Mediterranean. It is easier to explain why the Genoese were the first to
adopt it, as they had to confront Biscayan pirates on the route between the
Mediterranean and England and Flanders starting from the late 1270s. The cocha’s
high sides presented difficulties to assailants climbing from galleys. Moreover, the
cocha’s structure both protected its defenders and enabled crews to throw projectiles
at lower galleys. The coche’s high fore and aft castles provided battle platforms and
allowed crossbowmen time to aim and fire their improved crossbows, the main
weapon that could penetrate armor. Archers could also be stationed in the crow’s
nest. Furthermore, the straight stem post and sternpost enabled cutwater that
reduced leeway considerably, thus easing pointing to the wind while sailing to England
and northern Europe (Gertwagen, 2004: 554–555).
However, from the second half of the fourteenth century a new type of ship, the
carrack, appeared in the Mediterranean; from the second decade of the fifteenth cen-
tury, it became the typical navis in the West whereas only a small number could have
been seen in the Byzantine and Muslim worlds in the eastern Mediterranean. The
Venetian Pizigani’s portolan chart of 1366 is the first evidence for this new type of
vessel, several characteristics of which remained constant from the fourteenth century
through the first half of the sixteenth: a large, wide, deep and imposing hull with two
to three decks, ideal for bulk cargoes. Venetian and Genoese documents display car-
racks, with tonnage ranging from 300–600 tons. The carracks had a flat floor at least
amidships, a legacy from the cocha, and a curved stem with a marked rake and castles
fore and aft, the forecastle usually substantially higher than the after-castle. Its gradual
disappearance from iconography in the sixteenth century is one sign of the carrack’s
gradual transformation into another type of large vessel (Gertwagen, 2004: 555–556).
The other characteristics of the original northern cogs copied in the Mediterranean
concerned propulsion: the steering mechanism and the rigs. Until the fourteenth
century, all types of vessels had stern quarter steering oars (timoni), a standard feature
since Greek and Roman times, mounted on a single level pivot. As cargo ships
increased in size, the length and weight of the steering oars also grew, to up to 17 m
long and 11 tons in weight. They required complex tackle systems to control the oars,
notwithstanding the flotation effect of the water (Pryor, 1994: 71).
The introduction of the cog/cocha into the Mediterranean and the naus in
Catalonia in the late thirteenth century lead to major changes in Mediterranean
steering gears with the adoption of the northern stern rudder. Easier to use than the