The Viking ship was perhaps the greatest technical and artistic achievement of the European dark ages. These fast ships had the strength to survive ocean crossings while having a draft of as little as 50cm (20 inches), allowing navigation in very shallow water.
Ships were an important part of Viking society, not only as a means of transportation, but also for the prestige that it conferred on her owner and skipper. Their ships permitted the Vikings to embark on their voyages of trading, of raiding, and of exploration.
Images of ships show up on jewelry (right), on memorial stones (left), and on coins from the Viking age. Some people were buried in ships, or ship-like settings made of stones (below), during the Viking age.
The picture to the left shows a sketch of the side view and hull section, and a photo of a 9th century ship that was recovered early in the 20th century in Oseberg. The ship was part of a very rich burial and is now on display near Oslo.
The Oseberg ship was once thought to be more representative of a royal yacht, rather than a true war ship, but more recent research suggests she was quite capable of sailing in open ocean.
In the 1970's, five 11th century ships were found and recovered from the Skuldelev narrows in Denmark, giving us more examples of the variety of ships used in the Viking age. These ships had been intentionally scuttled, probably to block the channel during a raid.
Typically, a warship is narrower, longer, and shallower than a knörr, and is powered by oars, supplanted by sail. The warship is completely open and is built for speed and maneuverability. In contrast, a knörr is partially enclosed and powered primarily by sail. Cargo carrying capability is the primary concern.
The two Skuldelev warships are narrower and less spacious than the Oseberg ship. A sketch of the smaller of the two ships is shown to the right. She is 17.4m long (57 ft) and 2.6m broad (8.5 ft). These ships are probably more typical of the kind of vessel that was used by the Vikings on their raids.
A typical warship might have had 16 rowers on each side.
The crew's shields may have been arrayed along the gunwales, held in place by a shield rack outboard of the ship. This kept them out of the way, but also provided some slight additional protection against wind and waves.
The photos show the Íslendingur, a replica ship that sailed from Iceland to North America in the year 2000.
The inboard side of the shield rack on the replica Viking ship Vésteinn is shown to the left. In this interpretation, wedges hold the shield in place in the rack.
Perhaps shields were displayed only for battle, or to make the ship look especially fine when approaching land. Landnámabók (S.156) tells of Hella-Björn Herfinnsson who sailed into Bjarnarfjörður with his ship lined with shields. Afterwards, he was called Skjalda-Björn (Shield-Björn).
The oars of the Gokstad ship varied in length from 5.3 to 5.85 meters (about 17 to 19ft) according to where they were used on the ship. The oarholes were not a uniform distance above the waterline, and so the length of each oar was chosen so that the blades all hit the water in unison.
The oars were made of pine with a narrow blade, which makes for an efficient, lightweight oar. The photos show the oars for the Íslendingur, which was no longer afloat when the photos were taken.
The ship has been on display at an open air museum for several years, but in the fall of 2008, she was moved indoors to a new museum, Víkingaheimar at Reykjanesbær in Iceland.
The oarholes of the Gokstad ship were only 40cm (16 inches) above the deck. Most likely, each crewman's sea chest doubled as a rowing bench (right).
Oarholes were sealed when not in use by covers that rotated in place to keep out water (left).
The slot cut into the oarhole that is visible in the upper photo to the left allowed the blade of the oar to pass through the oarhole so oars could be deployed entirely inboard of the ship The slot was located in a position that received minimal stress while rowing, reducing the chance for wear or damage to the strakes or to the oars from the force of the stroke.
Warships typically had minimal decking, with removable planks under the rowers laid on the crossbeams (right), and small raised platforms at the bow and stern. When anchored or in harbor, an awning was arrayed overhead to provide some protection from the elements.
The single square rigged sail allowed sailing close to the wind. This ability, combined with the capability to row during adverse wind conditions, allowed Norse sailors to run in to shore, engage the enemy on land, and escape retribution at will.
The Helge Ask is a modern replica of the smaller of the two Skuldelev warships. She is based at the Roskilde Ship Museum in Denmark. They report that with a full crew of 24 at the oars, she is capable of a speed of 4 knots. But only for about 15 minutes, which is when the crew collapses from exhaustion. For longer stretches, 2-3 knots is probably her top speed when being rowed.
Another clue to the speed capabilities of these ships comes from linguistic studies. The term víka sjóvar is the distance a man should work the oars before he should be released. The distance was set to 1000 strokes, about two hours work. The modern term is equivalent to about 4 nautical miles, implying that a speed of 2 knots was typical.
Sea battles in the Viking age were fought on stationary ships and were more like land battles waged on floating islands. The battles had three parts. First, steersmen on each ship maneuvered for the most favorable position, relative to both friend and foe. Battles were fought in protected fjords, or in the lee of an island where marksmanship would not be spoiled by rocking decks. Missiles (such as arrows and spears) were fired as the ships closed and drew together. Sails were furled, and it is possible that masts were unstepped. Ships were tied together, creating floating islands.
Opposing crews tried to board the outermost ships in the tied-together fleet, with the goal of clearing the deck of the enemy. Hand to hand fighting on the decks of the ships determined the outcome. When the outermost ship was cleared, it was cut loose and set adrift, to make it possible to board the next ship making up the "island". Small boats swarmed around the battle to kill any combatants that tried to save themselves by jumping overboard.
A war ship was a valuable item, not only for the prestige and monetary value that went to her owner, but also for her utility in future battles. As a result, the intent in naval combat was to gain control of the ship (and any valuables she might be carrying) while minimizing any damage to the ship. This goal was achieved not by attacking the ship, but rather by attaching the ship's crew. The attackers attempted to sweep the decks free of the enemy without damaging the ship or her gear, and thus gain control of the ship.
The shallow draft of their ships allowed Vikings to set up impregnable bases deep within enemy territory. Viking ships could land anywhere there was a shelving beach; no harbor was necessary.
Chapter 4 of Bárðar saga Snæfellsás tells how the beach shown to the left got its name: Dritvík (Shit Bay). After Bárður Dumbsson beached his ship here, his men relieved themselves in the bay. The excrement washed up on the beach, thus the name.
Archaeological evidence supports the view that ships were beached regularly. The Skuldelev ships have wear on their keels consistent with sand and gravel landings.
In addition, the shallow draft made for fast and easy disembarkation during a raid. When the ship was beached, a Viking could be certain that if he jumped out near the stem, the water would scarcely be over his knees. The crew could leave the ship and join the raid quickly and confidently.
Under more normal conditions, conventional methods of boarding the ship were used. A gangplank was found on board the Oseberg ship.
Merchants and explorers used cargo ships called knörr. A sketch of one of the three 11th century knörr found near Skuldelev is shown to the left. This ship is a coastal trader and is 13.8m long (45 ft), 3.4m broad (11 ft), with a draft of 84cm (33 in). The loading capacity is approximately 4.1 tonnes (4.6 tons). A larger ocean-going trader found at Skuldelev was 16.3m long (53 ft) and 4.6m broad (15 ft) with a draft of 1.27m (50 in). However, she could carry nearly three times the cargo of the coastal trader: 13.6 tonnes (15 tons) filling over 30 cubic meters (more than 40 cubic yards). With a capacity this large, it is likely that she carried not only luxury goods, but also everyday objects in bulk quantities for trade. It's estimated that this ship's "effective" speed in regular ocean traffic was on the order of 3 to 6 knots.
However, greater speed may have been possible under good conditions. The saga literature suggests that the crossing from Norway to Iceland (a distance a bit less than 1000 nautical miles) was normally accomplished in a fortnight or so, but extraordinary crossings were accomplished in less than a week. Landnámabók says that the voyage from Stad in Norway to Horn in eastern Iceland takes seven days. Regardless, merchants typically made only a single one-way trip to Iceland each year, waiting through the winter before making the return voyage. Some voyages to Iceland took much longer. Gísla saga (chapter 4) says that Gísli's voyage from Norway out to Iceland took more than 60 days. Þórður emigrated from Norway with nineteen people on board, as is told in chapter 2 of Þórðar saga hreðu. They were at sea for a month before they made landfall at Vestmannaeyjar, off of Iceland's south coast. They continued sailing around Iceland to the west, arriving at Miðfjörður in the north five months after leaving Norway.
The knörr has half decks both fore and aft, each with a few oar-holes. (Oars were probably only used for maneuvering in preparation for landing.) A big open hole amidships comprised the cargo hold. Brushwood mats or straw under the cargo protected the ship from damage from the cargo. A crew of about six manned the coastal trader: a helmsman, a lookout, a bailer, and others sufficient to handle the sail. The ocean-going knörr probably had a crew of twelve who shared the profits.
Like the warships, the shallow draft of the cargo ships meant that they could easily be run up onto a beach for unloading, which was probably the usual way to land a ship. Ships were also sailed into shallow estuaries (ós) at high tide for loading and unloading. As the tide ran out, the ship was gently deposited on the bed of the estuary, where the cargo could be easily unloaded. Gísla saga Súrssonar (chapter 4) says that Þorbjörn súrr and his family arrived in Iceland and landed at Haukadalsós, the estuary at Haukadalur, where they made their home.
Ships were built using the "clinker" technique (right), in which the lower edge of each hull plank overlaps the upper edge of the one below. Planks (strakes) were riveted together using iron rivets. An assortment of rivets and washers are shown to the left, before use. Rivets were typically about 75mm (3 in) long. The total weight of rivets and washers used in the construction of a typical ship was about 150kg (330 lb), a very substantial and expensive amount of iron in the Norse era.
The value of the nails is apparent from an incident told in chapter 2 of Grænlendinga þáttur. Sigurður and his party came upon two ships beached next to a hut in the Greenland wilderness. Everyone from the ships was dead, and one of the ships was badly damaged. Sigurður had the rivets pulled and collected, then he burned the wreck. He returned home with the valuables and the undamaged ship, as well as with the bones of the dead men, so they could be buried in the churchyard.
Historical ships used much longer spacing between rivets than the modern reproductions shown in the photos on this page. Modern safety regulations require more closely spaced rivets for strength. Historical ships spaced the rivets as much as 60cm or more (24 inches) apart along the strakes, so the ship would be flexible in rough seas, bending and riding over the waves, rather than trying to resist them and taking the full impact of each swell. Thus thin-hulled Viking ships could survive the rough seas of the North Atlantic.
On some ships, the strakes were lashed to the frame using flexible lashings, rather than being firmly fixed, another way to create an elastic structure that rode over the waves. To the right is a sketch of the cross section of the planking of the Gokstad ship, showing how each plank was fastened to the frame.
However, on other ships, the strakes were fastened to the frame with wooden trenails (wooden dowels held in place by wooden wedges), and in some cases, by iron spikes. The trenails were preferred, since after installation, they swelled and held better than iron.
The structural elements of the Oseberg ship are shown to the left, showing the keel (blue), strakes (light blue), rib (green), crossbrace (yellow), knees (light red), and stanchion (magenta). Where each strake crossed a rib, a cleat was fabricated on the inboard side of the strake that stood proud above the surface of the strake. The rib rested in the cleat, and the lashing that fixed the strake to the rib passed through the cleat.
Even though cracks between the planks were sealed with moss or animal hair coated with tar, the elasticity of the ships made them prone to leaks, especially in rough seas. The sketch to the left shows (and probably with some accuracy) the cargo hold of a knörr knee-deep in water, despite the bailing by the crew. It's likely that one crew member bailed full time, with others helping when necessary.
In chapter 17 of Grettis saga, there's a description of bailing during rough seas. The crew was forced to bail round the clock. Two buckets were used, with a full one carried up while the empty one was passed back down to be refilled. When Grettir took over filling the buckets, eight men were needed to empty the buckets in order to keep up with him.
A sketch of an 11th century bailer is shown to the right. The bailer is made of wood and is about 50cm (20 in) long. There is also evidence of drain plugs in some hulls, to empty the water when the ship was pulled up on shore.
Oak was used throughout the ship. Tall, straight trees were selected for masts and planks. The archaeological evidence shows that the quality of ship timbers declined throughout the Norse era. Later ships were made with planks that were shorter and less broad, because fewer high-quality oak trees were available. Some ships were built with wood salvaged from earlier ships, as evidenced by the Skuldelev 5 ship (which has been described as a "coffin ship" because of its poor construction and low level of seaworthiness). By the end of the Norse age, pine was extensively used.
Ole Crumlin-Pedersen has estimated that for a typical 20m (65 ft) longship, approximately 58 cubic meters (2000 cu ft) of oak was required. This is equivalent to eleven oak tree trunks, each 1m in diameter and 5m long, along with a single 18m long trunk for the keel. Oaks of this size and of sufficient quality would be difficult or impossible to find today. The keel of the Gokstad ship required a tall, straight oak about 25m (80ft) tall.
Pine logs were typically split only once, and the strakes were cut down from the resulting two halves of the log.
Due to the lack of suitable forests, it's unclear whether Iceland had a ship-building tradition during the Viking age. When the first settlers arrived, much of the land was forested, with birch predominating. However, it would seem that the tall, straight trees needed for keels and masts would be in short supply.