A Viking longboat conveys the traditions of the seafaring Scandinavian people on any body of water. While the full-scale Viking longboat is beyond the financial resources and construction abilities of most craftsmen, plans and construction techniques for these boats are available on the Internet and from other resources. The methods used to build the longboat can also be used to construct the smaller vessels associated with the Viking sailing tradition.
Laying the keel is the first step in most shipbuilding projects, and the Viking longboat is no exception. The keel, a heavy beam that is the backbone of the ship, runs along the centre of the bottom of the hull. The keel of a Viking longboat is shaped into T with the upper wings angled slightly upward. The boards that form the hull of the boat will be fastened to the undersides of the upper portions of the T.
Fasten the stem and stern to the keel. The stem is the beam that continues the keel upward on the front or bow of the boat. The stern serves the same task on the rear of the boat. Traditionally, wooden plugs are used to make this attachment. Modern construction could include drilling holes through the keel and stem or stern and bolting the pieces together. No matter what method is used to attach the stem and stern posts to the keel, the connection must be solid.
Attach the first course of the hull boards or strakes to the keel. Each course of the strakes is lapped over the previous strake. This type of construction is known as lapstrake and is common in Viking and Scandinavian boats. Traditionally, the strakes are attached to each other by a method known as iron clinkering. A nail is driven through the strakes from the outside. Any protruding portion of the nail is cut off and the nail is then clinched by hammering on both sides of the board. Additional courses of strakes are added until the hull of the boat is complete.
Build the interior ribs of the boat. Ideally, these are made from naturally bent logs. However, finding just the right piece of wood is difficult in the modern world. Instead the ribs are often made from multiple pieces of wood assembled to create the proper angles to support the hull of the boat. The ribs serve to provide strength and rigidity to the hull. They will also serve as the supports for any boat deck built into the longboat and the point of attachment for the mast.
Reinforce the gunwale, which is the top strake of the hull, and attach any riggings necessary for the sail and the oarlocks. Install any seats and decking as well as the rudder. Decking is supported by the ribs installed in the previous step. Seats or benches are installed to place the crew properly for rowing the Viking longboat. Treat the boat with a mixture of turpentine and tar. Apply a first coat made up of a higher portion of turpentine to allow the mixture to penetrate the wood. A second or even third application can be made with a higher concentration of tar. The formula will vary depending on the thickness of the tar.
Leaks can be expected during the first few days the boat is in the water. As the wood gets wet it will swell and alleviate the leaks, hopefully. Work tar-soaked rags or ropes into any seams not sealed when the wood swells. Make sure the boat's drain hole is plugged anytime the boat is in the water.
Always wear life vests or have appropriate flotation devices on board when the longboat is in use. Keep another boat nearby during initial sailing trials of the craft.