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. Overall displacement: 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. This type of ship was used for longer voyages than the Gokstad type of ship and also hazardous trips. It is also shorter and sturdier than the Gokstad. 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 cog, used in the Baltic Sea by the Hanseatic League.
Most of their voyages were 300- 500 miles long, taking 3-5 days at a time.
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. he 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.
Merchants and explorers used cargo ships called knörr. 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.
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.
The quickest voyages between Iceland and Norway were of course done under ideal conditions and maybe with some luck. The shortest route between the countries is from the coast north of Bergen to the southeastern coast of Iceland (Horn) and the quickest voyages between these points may have taken 3 days or so. If you were traveling beween other places a few days should be added to this number. These figures apply to ideal conditions whereas in reality voyages beween the countries would often take several weeks. Thus, for instance, it was considered to be a feat worth special mention if the merchants would make two return voyages in the same summer.
Later ships were made with planks that were shorter and less broad, because fewer high-quality oak trees were available. 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.
It’s unclear how many man-hours were required to build a ship. King Óláfr Tryggvasson’s Long Serpent was built in one winter by a team led by a master ship builder. The team members included four different kinds of specialists: tree fellers; laborers; plank-cutters; and stem-smiths. In contrast, the modern knörr replica Roar Ege took several dozen people two years to build.
A ship’s sail was a very precious item. It’s quite possible that the sail cost as much to make as the hull. Typically, the sail was made from the finest grade of homespun wool, woven on the same vertical loom (right) in the home that was used for clothing. It has been suggested that it took several women several years to make the fabric needed for a single sail. On the other hand, chapter 68 of Egils saga says that while Egill stayed with Arinbjörn one winter in Norway, he had an elaborate sail made for Arinbjörn as a gift.