Sunday, May 10, 2015

Ships were integral to the Crusades

Crusader vessel - medieval cog

Ships were integral to the Crusades. Most Crusaders gathered on the coast of southern France and embarked at Marseilles. Since their warfare was dependent on horses and they could not easily buy or train them on the other side of the journey, they had to get ships with stables built below the deck. Travel was uncomfortable; knights traveled with retinues of servants and squires, and the ship was too crowded to afford sleeping quarters for all of them. Although this 15th-century painting imagines the voyages in a cheerful way, the actual conditions must have been squalid. Horses needed some rest periods on islands in order to regain their health.

The Romans had used two basic kinds of ship. Galleys were their warships, and they used cargo ships known as round ships. During the Middle Ages, both types were adopted and improved on century by century. Early Byzantine dominance was challenged by new Muslim navies in the seventh century. Although the Arabs had been sailing the Indian Ocean in Indian-style ships, their Mediterranean fleets were in the same style as the Roman and Byzantine ships, since they bought surplus ships and hired local crews.

Roman warships were galleys that moved by means of both sail power and the muscle power of dozens of men at the oars. The basic Roman galley had been developed into larger versions—the bireme and the trireme— that used two or three levels of oarsmen, with several men on each oar. An even-larger galley had used five levels of oarsmen. Throughout the Middle Ages and even into the 18th century, Mediterranean warships continued to be galleys, most of them using both oars and sails.
One important development formed the principal warship of the Byzantine Empire—a dromon. There were three variations of the dromon. The smallest, the ousiakon, carried a company of 100 men (an ousia ). It was a two-banked galley. The men on the lower bank only rowed; the men on the upper bank rowed but were also the fighters in battles with other ships. The pamphylos was a little larger; it carried a crew of more nearly 150. The true dromon carried a crew of about 200, with 150 oarsmen on two banks of oars and 50 marines (fighting men). These larger dromons had a raised tower near the mast, where the marines could stand to shoot arrows or throw spears or other projectiles. Most dromons also carried either a powerful catapult, which could throw a 20- or 25-pound object more than 250 feet, or a pressurized siphon flamethrower that propelled liquid Greek fire onto the enemy ship’s deck. Greek fire was an incendiary substance that continued to burn even when it hit water.
Venice created its own version of the dromon while it was under Byzantine rule. It was called the galeagrossa, and it was put to both commercial and military use. In the Mediterranean, the two purposes ran together. Merchant ships needed defense, and navies had to carry cargo. Sailors learned to fight. Venice’s Arsenal built galleys that eventually challenged the cogs’ dominance in bringing Flanders wool to the Mediterranean.

Mediterranean ships, beginning with Greek fishing boats and including the massive dromon, developed a new type of sail during the Byzantine era. Roman sails had been square, but square sails moved a ship only in the direction the wind was blowing; adjustments allowed some variation but not much. Lateen sails were triangular, not square. They were hung from a yard (crossbar) that was fixed partway up the mast at a slant. A long, narrow triangle of sailcloth hung down almost to the deck. This shape creates a baggy lower part of the sail that traps the wind and funnels it up to the narrow top, creating a substantial amount of lift when a ship is sailing with the wind. It could be angled to let a ship steer a course that was not directly with the wind or almost against the wind. By the ninth century, the ships of the Mediterranean were generally lateen rigged and capable of working their way windward. The triangular sails were huge, and the yards they were fastened to were made of large tree trunks. The square sail eventually made a comeback around the 1300s, partly because of the amount of manpower needed to swing lateen rigging around. The square sail caught more wind and enabled the ship to move faster. 

Mediterranean ships were not only different in having galleys of oars and lateen sails; they were constructed in a completely different manner from Baltic and North Atlantic ships. Viking ships and the cogs of northern waters were clinker-built: outer shell first, with overlapped strakes, and then construction of the inner framework. The method of construction in southern waters was just the opposite. They built the framework first, with beams and ribs, and then covered the framework with planking. Boats built this way are called carvel-built. Three medieval shipwrecks show advances in construction methods over several centuries.

A carvel-built hull from the seventh century found in the eastern Mediterranean, off the coast of Turkey, shows the basic construction method. The builders laid the keel first, then added high, curved endposts. They fastened planks alongside the keel, joined by mortise and tenon and pinned by trenails (wooden pegs that swell when wet to tighten the construction). They added planking up to the waterline, nailed to a framework, and set crossbeams from side to side to bind the hull together. These crossbeams protruded through the hull. At the stern, the crossbeams were a good place to hang a steering rudder on each side of the hull. In the middle of the ship, crossbeams helped support the mast. This particular ship was about 67 feet long and could carry more than 65 tons of cargo. When it sank, it was carrying 900 containers (amphorae) of wine. It also carried 11 anchors.

Another wreck along Turkey was dated by coins to the 11th century. The cargo was mostly glassware, and this ship also carried a large number of anchors. The carvel construction was more advanced by the 11th century. The framework was laid out, then curved timber ribs were added and planking was nailed on with iron spikes. The alternating of the scarphed joints contributed to the strength of the hull, as there was no continuous line of joints across the ship. A third wreck from the estuary of the Po River was dated to about 1300 and was 65 feet long. A new method made the ship strong enough to hold two masts. They used frames attached to floors that crossed the keel and were then secured to a timber bolted to the keel for extra strength.

In the years after 1000, the role of the ship changed dramatically. Commerce was increasing, merchants were becoming wealthy, and ships were increased in size to hold more cargo. After Crusaders set up a Christian kingdom in Jerusalem, there was a great surge of Christian pilgrims wanting to visit Jerusalem. All these factors created demand for larger ships.

The Crusades spurred a great deal of shipbuilding to transport knights and horses from Marseille or Venice to the Holy Land. At first, Crusaders rented any ships they could find, but by the Third Crusade of the 13th century, more were required. King Louis IX of France contracted with merchants in Genoa, Venice, and Marseille to provide custom-built ships for his two Crusades, in 1248 to 1254. These were substantial vessels, several with three decks. The horses were led into the ship through a door that was then caulked shut to keep water out when the ship went out to sea.

In the 15th century, the Baltic and Mediterranean traditions began to mix. The Hanseatic League had extended its reach into ports in the Mediterranean, and Venetian galleys were trading directly in Flanders. One early hybrid was the buss, a wide, carvel-built cargo fishing ship built in the Netherlands. Using the buss, Dutch sailors could stay out at sea longer. The buss sailed with the fishing boat; it was a floating fish-processing plant. The pair of vessels could stay out for several weeks and return with its catch salted while fresh.

The ultimate round ship of the late Middle Ages was the three-masted, full-rigged, ocean-going carrack. The carrack’s precursor was the cog, the clinker-built cargo carrier of the Hanseatic League. In Mediterranean shipyards, the cog had been modified and refined; it was no longer clinkerbuilt but was now carvel-built. Its sails also blended the best of north and south.

The carrack was large and heavy. Huge ribs formed the hull and supported multiple decks, a high sterncastle, and an even higher (though smaller) forecastle. The ship’s tiller passed through a port to move the sternpost rudder. The edge-to-edge planking of the ship was caulked with oakum and tar or pitch to help keep seawater out. For the same reason, the ship was constructed with few hatches and no companionway (a stairway leading from the deck to the cabins below). Its three masts were the main mast and foremast, both square rigged, and the lateen-rigged mizzenmast, which rose from the sterncastle. Later versions of the carrack included another small sail—the spritsail on the bowsprit. Improvement in managing the ropes made the huge sails easier to handle, and multiple sails gave versatility to managing the course of the ship.

A large merchant carrack could carry 1,000 tons of cargo in its hold as it moved around the whole length of the Mediterranean and to and from the Baltic. Its great size made it an expensive ship, and it was expensive too in that it required a large crew. There were smaller carracks, too, such as the 100-ton Santa Maria, the ship that carried Christopher Columbus to the islands of Central America.
Columbus’s other ships, the Niña and the Pinta, were caravels, not carracks. The caravel was a fast sailing ship developed in Portugal around 1440. It carried two or three masts, with either lateen sails or a mixture of square and lateen. The caravel had excellent sailing characteristics and did not need the large crew that was necessary on a carrack. It could move at a relatively fast pace; records show that on the return trip from America in 1493, the Niña and Pinta had at least one day when they covered nearly 200 miles of ocean. Caravels were generally the ships of choice for the voyages of exploration that marked the end of the 15th century and continued into the 16th century.

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