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Nordic Sagas: Viking Ships

For nearly three centuries, Vikings sailed the rough oceans in their sleek, streamlined ships, traveling far from Scandinavia to distant lands where they built settlements. How they sailed to North America and other parts of the world has long been a mystery, but ships buried in the mud of Danish fjords are providing some answers. Frontiers joins archaeologists reconstructing ships that will sail on the same waters traveled by Viking ancestors so long ago.

Curriculum Links
Viking Ship Design
Activity: A Balance of Forces
Why the Right Side of a Boat Is Called the Starboard Side




forces, vortices


exploration, Leif Ericson, Vikings


engineering design


From the 8th to the 11th centuries, Vikings dominated the seas in the northern hemisphere. Their superior ship design and physical prowess enabled them to sail many thousands of miles from their homes in Scandinavia and establish settlements in many areas, from what is now Russia to the Mediterranean, Britain, France and North America -- 500 years before Columbus.

As you see on Frontiers, Viking boat builders employed technological advances for their age. Their ships' streamlined hulls and shallow keels meant the sleek vessels rode high in the water and skimmed the surface. A square sail that could be raised and lowered quickly meant sailors could easily shift from wind to muscle power.

Among the Vikings' technological innovations in ship design was a unique side rudder. The method of attachment allowed the rudder to be lifted out of the water quickly, so ships could maneuver right up to shore. Not having to anchor ships in a harbor gave the Vikings another advantage.

Ships were so much a part of the Viking culture that great leaders were even buried in them. Archaeologists have found several ships buried long ago, complete with treasures intended to accompany the hero on his journey to the next world.

The Vikings, who lived in what is now Iceland, Denmark, Norway and Sweden, landed in North America by 1003. To commemorate the anniversary, the Leif Ericson Society has organized the Leif Ericson Millennium. The international celebration begins on Leif Ericson Day, October 9, 1999, and continues for one year. The celebration will re-enact Leif Ericson's voyage to North America or "Vinland" using replica Viking ships.


Now it's your turn to be a naval architect. In this challenge you'll construct a wind-powered model of a Viking ship. The ship will have to follow a course set by your rudder. You'll need to build your model and examine the relationship between rudder shape, placement and steering angle.


Observe and critically examine the role of the rudder in steering.

  • waterproof clay
  • heavy stock paper
  • tape
  • thin wooden dowel or plastic coffee stirrers
  • index card
  • battery-powered fans
  • small wading pool or large basin
NOTE: To prevent any possibility of electric shock, do not use a fan powered by an electrical outlet. Although this activity can be performed with a single fan, additional fans will produce uniform coverage of the water's surface. Several small battery-powered fans will work for the entire class setup.


  1. Place the empty pool or basin either outdoors or in a classroom "wet area."

  2. Fill the pool or basin with water to a depth of four inches (10 cm).

  3. Position the battery-powered fan(s) at one end of the pool or basin. The fans will simulate the "prevailing winds" that will power the ships. The fans should be secured on top of a stack of books or similar platform so that breezes flow unobstructed -- across the water's surface.

  1. Shape the hull of your model Viking boat from a walnut-sized lump of waterproof modeling clay.

  2. Cut out a section of stiff paper for a sail. You may want to decorate the sail with Viking symbols and designs.

  3. Use a thin wooden stick or coffee stirrer as the model's mast. Tape the sail to the mast and position it in the clay hull. Secure the base of the mast with a small piece of clay.

  1. When you have your boat ready, draw a rudder on an index card and cut it out. (Part of your challenge is to experiment with shape and size of the rudder.)

  2. Press it into the hull on the right (starboard) side of the boat, near the rear (stern).

  1. Place your model ship in the pool or basin (closest to the fans). Set the rudder and sails so that the ship will travel a straight course. Release and observe its motion.

  2. Vary the rudder angle and observe how this affects the ship's course. Make sure to record your observations. Try to come up with a relationship between rudder angle and course heading.

  1. Your instructor will identify the starting point and the "sailing target" to which your boat must head. The winning model boat will come closest to the target.

  2. You may modify the rudder's position only before the trial begins. Once the boat has been placed and launched, you may not adjust the rudder. Good luck!


  1. Compare the side rudder to ships' rudders used today.

  2. For more about the Vikings, visit these Web sites:
    Click on the May 1997 issue of Maritime Archaeology to find out more about the Roskilde ships.
    Take a photo tour of Iceland's Golden Circle.
    Travel back in time to the world of the Vikings and visit sites in many parts of the world.

  3. You can learn more about Viking ships, order a kit to build one and find out about re-enactments and other events from Leif Ericson Viking Ship, Inc., based near Philadelphia, Pa. Find out more at

  4. See the February 1998 issue of Scientific American for an article about Viking ships.

  5. Evidence suggests the Earth was much warmer during the Viking era. How would such a climate shift have made a difference to Viking sailors?

  6. During the Viking era, Polynesians sailed the South Pacific, colonizing what is now Hawaii and other islands. Compare ship designs and distances traveled by Polynesian and Viking sailors.


Viking ships were steered with an oar-like rudder called a styri, attached to the right-hand side of the ship near the stern. The Vikings called this side of the ship stjornbordi. Today the right-hand side of any boat is known as the starboard side.

As you see on Frontiers, the projection on the trailing edge of the rudder is theorized to break up the turbulence (vortices) caused by friction of the fluid/hull interface. Similarly, some 747s have a projection on the airfoil surface that breaks up turbulence caused by air flow.

In the late 9th century, Vikings invaded and settled areas in France. One region became Normandy, named after the Norsemen. In 1066, the Normans invaded and conquered Britain in the famous Battle of Hastings, commemorated in the Bayeux Tapestry. In the tapestry, you can clearly see Viking ship designs, complete with side rudder.


Scientific American Frontiers
Fall 1990 to Spring 2000
Sponsored by GTE Corporation,
now a part of Verizon Communications Inc.