Discoverers, Navigators and Cartographers

Parts of the following text are quoted from http://en.wikipedia.org/wiki/Viking_Age and from http://en.wikipedia.org/wiki/Viking_ship

Viking Navigators

Late in the 9th century Norse Vikings explored the north atlantic, resulting in the foundation of independent settlements in the Shetland, Orkney, and Faroe Islands and later on Iceland and Greenland. After Erik the Red had explored and settled in Greenland in 986, an expedition under his sun Leif Ericson, reached North America around 1000 and set up short-lived settlements in present-day L'Anse aux Meadows, Newfoundland, and Labrador, Canada. This was about fivehundert years before Columbus re-discovered the american continent.

For the next couple of centuries, an intense north atlantic trading trafic developed between Norway and the colonies in Iceland and Greenland during which Norse Viking developed great maritime skills allowing them to navigate through stormy and foggy seas. But by about 1500 the settlements in Greenland were abandoned and the Norse Greenlanders and their explorations of the New World receded into the realms of myth.

Technology

The Vikings were equipped with the technologically superior longships; for purposes of conducting trade however, another type of ship, the knarr, wider and deeper in draft, were customarily used. The Vikings were competent sailors, adept in land warfare as well as at sea, and they often struck at accessible and poorly defended targets, usually with near impunity. The effectiveness of these tactics earned Vikings a formidable reputation as raiders and pirates.
Chroniclers paid little attention to other aspects of medieval Scandinavian culture. This slant was accentuated by the absence of contemporary primary source documentation from within the Viking Age communities themselves. Little documentary evidence was available until later, when Christian sources began to contribute. As historians and archaeologists have developed more resources to challenge the one-sided descriptions of the chroniclers, a more balanced picture of the Norsemen has become apparent.

The Vikings used their longships to travel vast distances and attain certain tactical advantages in battle. They could perform highly efficient hit-and-run attacks, in which they quickly approached a target, then left as rapidly before a counter-offensive could be launched. Because of the ships' negligible draft, the Vikings could sail in shallow waters, allowing them to invade far inland along rivers.

The ships' speed was also prodigious for the time, estimated at a maximum of 14-15 knots (26-28 km/h). The use of the longships ended when technology changed, and ships began to be constructed using saws instead of axes. This led to a lesser quality of ships.

While battles at sea were rare, they would occasionally occur when Viking ships attempted to board European merchant vessels in Scandinavian waters. When larger scale battles ensued, Viking crews would rope together all nearby ships and slowly proceed towards the enemy targets. While advancing, the warriors hurled spears, arrows, and other projectiles at the opponents.

When the ships were sufficiently close, melee combat would ensue using axes, swords, and spears until the enemy ship could be easily boarded. The roping technique allowed Viking crews to remain strong in numbers and act as a unit, but this uniformity also created problems. A Viking ship in the line could not retreat or pursue hostiles without breaking the formation and cutting the ropes, which weakened the overall Viking fleet and was a burdensome task to perform in the heat of battle. In general, these tactics enabled Vikings to quickly destroy the meagre opposition posted during raids.

Together with an increasing centralization of government in the Scandinavian countries, the old system of leidang - a fleet mobilization system, where every skipen (ship community) had to deliver one ship and crew - was discontinued. Changes in shipbuilding in the rest of Europe led to the demise of the longship for military purposes. By the 11th and 12th centuries, European fighting ships were built with raised platforms fore and aft, from which archers could shoot down into the relatively low longships.

The nautical achievements of the Vikings were exceptional. For instance, they made distance tables for sea voyages that were remarkably precise. They have been found to differ only 2-4% from modern satellite measurements, even on such long distances as across the Atlantic Ocean. The archaeological find known as the Visby lenses from the Swedish island of Gotland may be components of a telescope. It appears to date from long before the invention of the telescope in the 17th century. Recent evidence suggests that the Vikings also made use of an optical compass as a navigation aid, using the light-splitting and polarization-filtering properties of Iceland spar to find the location of the sun when it was not directly visible.

Viking ships

The war ship was the cultural icon of the Vikings. Ships functioned as the centrepiece of Scandinavian culture for centuries. In fact, the importance of the Viking ship is deeply rooted in Scandinavian culture, as the vessel served both pragmatic and religious purposes. Scandinavia is a region with relatively high inland mountain ranges and easy access to coastal ports. Consequently, trade routes primarily operated via shipping, as inland trading was both hazardous and cumbersome.

Viking kingdoms thus developed into coastal cities, all of which were deeply dependent on the North Sea for survival and development. Control of the waterways was then of critical importance, and consequently the most advanced war ships were in high demand. In fact, because of their overwhelming importance, ships became a mainstay of the Viking pagan religion, as they evolved into symbols of power and prowess.

Scandinavian tradition of shipbuilding during the Viking Age was characterized by slender and flexible boats, with symmetrical ends with true keel. They were clinker built, which is the overlapping of planks riveted together. They might have had a dragon's head or other circular object protruding from the bow and stern, for design, although this is only inferred from historical sources.

They ranged in the Baltic Sea and far from the Scandinavian home areas, to Iceland, Greenland, Newfoundland, the Mediterranean, and Africa.

The ships are normally divided into classes based on size and function:

Knarr: The knarr is the Norse term for ships that were built for Atlantic voyages. They were cargo ships with a length of about 54 feet (21m), a beam of 15 feet (4.5m), and a hull capable of carrying up to 24 tons with an overall displacement of 50 tons. Knarrs routinely crossed the North Atlantic centuries ago carrying livestock and stores to Greenland. It was capable of sailing 75 miles within in one day and held a crew of about 20-30 men. This type of ship was used for longer voyages and also hazardous trips. It depended mostly on sail-power and used its oars only as auxiliaries if there was no wind on the open water. The vessel also influenced the design of the later cog, used in the Baltic Sea by the Hanseatic League.
Karve: Karves were a type of small Viking ship similar to the knarr. They were used for human transport, the movement of livestock and other goods. Because they were able to navigate in very shallow water, they were also used for coasting. Karves had broad beams of approximately 17 feet (5.2 m).
Faering: A faering is an open boat with two pairs of oars, commonly found in most boat-building traditions in Western and Northern Scandinavia and dating back to Viking era Scandinavia.
Longship: Longships were naval vessels made and used by the Vikings from Scandinavia and Iceland for trade, commerce, exploration, and warfare during the Viking Age. The longship-s design evolved over many years, beginning in the Stone Age with the invention of the umiak and continuing up to the 9th century with the Nydam and Kvalsund ships. The longship appeared in its complete form between the 9th and 13th centuries. The character and appearance of these ships have been reflected in Scandinavian boat-building traditions until today. The average speed of Viking ships varied from ship to ship but lay in the range of 5-10 knots and the maximal speed of a longship under favourable conditions was around 15 knots.

The long-ship is characterized as a graceful, long, narrow, light, wooden boat with a shallow draft hull designed for speed. The ship's shallow draft allowed navigation in waters only one metre deep and permitted beach landings, while its light weight enabled it to be carried over portages. Longships were also double-ended, the symmetrical bow and stern allowing the ship to reverse direction quickly without having to turn around; this trait proved particularly useful in northern latitudes where icebergs and sea ice posed hazards to navigation. Longships were fitted with oars along almost the entire length of the boat itself. Later versions sported a rectangular sail on a single mast which was used to replace or augment the effort of the rowers, particularly during long journeys.

Longships can be classified into a number of different types, depending on size, construction details, and prestige. The most common way to classify longships is by the number of rowing positions on board. Types ranged from the Karvi, with 13 rowing benches, to the Busse, one of which has been found with an estimated 34 rowing positions.

Longships were the epitome of Scandinavian naval power at the time, and were highly valued possessions. They were often owned by coastal farmers and commissioned by the king in times of conflict, in order to build a powerful naval force. While longships were used by the Norse in warfare, they were troop transports, not warships. In the tenth century, these boats would sometimes be tied together in battle to form a steady platform for infantry warfare. They were called dragonships by enemies such as the English because they had a dragon-shaped bow.

The best excavated and preserved ancient viking ships (Tune, Gokstad and Oseberg) can be seen by visiting the permanent public exhibition of The Viking Ship Museum at Bygdøy, Oslo in Norway. Another very interesting place to visit is the "Vikingeskibsmuseet" in Roskilde, Danmark. The Viking Ship Museum is focused on ships, seafaring and boatbuilding culture in ancient and medieval times. But the museum has also a boatyard, which is very active in projects on maritime experimental archaeology, which resulted in the building of some fully seaworthy replica of viking ships, especially of the Skuldelev series.

Propulsion

The longships had two methods of propulsion: oars and sail. At sea, the sail enabled longships to travel faster than by oar and to cover long distances overseas. Sails could be raised or lowered quickly. Oars were used when near the coast or in a river, to gain speed quickly, and when there was an adverse (or insufficient) wind. In combat, the variability of wind power made rowing the chief means of propulsion.

Longships were not fitted with benches. When rowing, the crew sat on sea chests (chests containing their personal possessions) that would otherwise take up space. The chests were made the same size and were the perfect height for a Viking to sit on and row. Longships had hooks for oars to fit into, but smaller oars were also used, with crooks or bends to be used as oarlocks. If there were no holes then a loop of rope kept the oars in place.

An innovation that improved the sail's performance was the beitass, or stretching pole - a wooden spar stiffening the sail.

Construction

Viking ships varied from others of the period, being generally more seaworthy and lighter. This was achieved through use of clinker (lapstrake) construction. The Vikings built their ships of fresh wood. The long planking for the ship's sides, the strakes, were cleaved from long, straight oak trunks, while the inner and more curved timbers were made from parts of the oak tree crown that had already grown into more or less the correct form.

The planks from which Viking vessels were constructed were rived (split) from large, old-growth trees - especially oaks. A ship's hull could be as thin as 2.5 cm, as a split plank is stronger than a sawed plank found in later craft.
Working up from a stout oaken keel, the shipwrights would rivet the planks together using wrought iron rivets and roves. Ribs maintained the shape of the hull sides, but were not intended to provide strength to the hull. Each tier of planks overlapped the one below, and waterproof caulking was used between planks to create a strong but supple hull.

Remarkably large vessels could be constructed using traditional clinker construction. Dragon-ships carrying 100 warriors were not uncommon. Furthermore, during the early Viking Age, oar ports replaced rowlocks, allowing oars to be stored while the ship was at sail and to provide better angles for rowing. The largest ships of the era could travel five to six knots using oar power and a hasty ten knots with the sail hoisted.

Navigation

With such vast technological improvements, the Vikings began making increasingly more ocean voyages, as their ships were infinitely more sea worthy. In order to sail in ocean waters, the Vikings needed to develop methods of relatively precise navigation.

Most commonly, a ship was piloted using ancestral knowledge. Essentially, the Vikings simply used prior familiarity with tides, sailing times, and landmarks in order to route courses. In fact, scholars contend that the mere position of a whale allowed the Vikings to determine their direction. Whales feed in highly nutritious waters, commonly found in regions where landmasses have pushed deep-water currents towards shallower areas. The sighting of a whale consequently functioned as a signal land was near.

However, some academics also argue that the Vikings developed more tangible means of navigation. Many claim the Vikings used a sun compass to show their direction. This compass comprises a vertical pointer on a horizontal surface, on which the shadow of the pointer, the so-called gnomon, is drawn through the day. The shadow curve is different at different latitudes and at different times of the year, so in order to use it for navigation, a series of curves is necessary. A wooden half-disc found on the shores of Narsarsuaq, Greenland seems to initially lend credibility to this belief. However, researchers found that the slits circumnavigating the disc are disproportionately spaced, casting severe doubts about its role as an accurate compass. Many now hold that the instrument is a "confession disc", used by priests to count the number of confessions in their parish.

In a similar sense, researchers and historians continually debate the use of sunstone in Viking navigation. Recent studies identify the sunstone, with its ability to polarize light, as a plausible method for determining direction. The sunstone effectively has the potential to show the positioning of the sun, even if obscured by clouds, by showing which direction light waves are oscillating. The stone will become a certain colour based on the direction of the waves, but the process is only possible if the object is held in an area with direct sunlight. Thus, most scholars debate the reliability and the plausibility of using a navigational tool that can only determine direction in such limited conditions.

Viking sagas routinely tells of voyages where Vikings suffer from being "hafvilla" (bewildered): voyages beset by fog or bad weather where they completely lost their sense of direction. This description suggests they did not use a sunstone to aid them when the sun was obscured. Also, they would experience hafvilla when the wind died, implying they relied on prevailing winds to navigate, further supporting the use of ancestral knowledge for piloting.

Sources

1. http://en.wikipedia.org/wiki/Viking_Age
2. http://en.wikipedia.org/wiki/Viking_ship
3. "The Last Vikings: The Epic Story of the Great Norse Voyagers", Kirsten A. Seaver, 2010, I.B. Tauris & Co Ltd., London - New York

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last updated: 26-Feb-2012