The Lovund boat is an open, clinkerbuilt vessel, where the primary source of propulsion was a square-rigged sail. The boat was c. 12.2 m long and 3.65 m wide. It was built of oak, and the planks are clinked with iron rivets that have square roves. It has 11 strakes.
The keel is rabbeted. It has a U-shaped beam form and is 9 m long. The garboard was fastened to the keel against an angled contact surface using nails placed at relatively even intervals. This sharply angled construction meant that the keel and garboard worked together to stabilize sailing direction, which increased manoeuvrability for the boat and hindered it from drifting off course. The stern end of the keel is intact. Directly forward of the stern end there is a rectangular mortise hole from a mortise and tenon joint to attach the sternpost. On the starboard side there are four nail holes, and on the port side there are five nail
holes to fasten the joint. The sternpost was therefore fastened to the keel with nails.
The possible remains of the sternpost confirm the interpretation that the stern was vertical. At the port side of the bow, a damaged part was found that the archaeologists interpreted as a fragment of the stem. The angled form and two characteristic holes support this interpretation.
Boat planks: Strakes
After the keel is laid and the stems raised, the boat planks are the next construction element !e lowest planks in the boat are fitted and mounted before the frames are put into place. It is not unlikely that the planks are sawn. The Lovund boat has 11 strakes, and 113 parts are defined as boat planks, or fragments of planks. The longest preserved plank is 5.17 m long. The width of the planks with intact edges is 224-292 mm, while thickness varies #om 20-40 mm with an average of 25 mm. The strakes overlap at the lands, that have an average width of 50.9 mm.
Inner timber: Frames
The placement for 15 of the frames can be seen in the excavation plan drawing of the boat. Only a few of these are in situ, while most of the other frames have come loose from the construction, some already in 1976. !e #ames make up the inner and transverse strengthening elements of the boat. In shell-first constructed boats these are placed a%er the boat planks are laid down. It is not the frames that define the hull form, but their function is rather to bind together the boat planks and give strength to the hull against outside forces. The frames in the Lovund boat consist of a floor timber, futtock, and top timber. Twenty-eight parts have been defined as frames. There are seven floor timbers, seven futtocks and two top timbers preserved. The floor timbers, which are the best preserved frame parts, are c. 140-150 mm wide and 90-100 mm high. They have been fastened to the ship planks with treenails with small wedges from the inside and the nails are placed far down on the planks, near the land. The frames are placed at an average distance of 0,54 m apart, measured from centre to centre of the nail holes. Including the forward frame, the boat had a maximum of 19-20 frames.
Inner timber: Crossbeams
The transverse crossbeams are important for stiffening the hull. A single crossbeam was found in the boat. Unfortunately, it cannot be used to define the width of the hull. It is 1.82 m long and made of a naturally grown piece of timber that forms a 90-degree angle (the knee). Two treenails have been used to fasten it to the hull. There are also treenails on the crossbeam arm. There must have been additional knees and crossbeams in the boat. The question of whether some of the crossbeams may have had heads that went through the hull is undetermined.
Longitudinal strengthening: rubbing strakes and stringers
Placement of the rubbing strakes and stringers can be seen in the excavation plan drawing of the boat. The boat has longitudinal strengthening, both on the inside (stringers) and outside (rubbing strakes) of the boat. On the outside there were mouldings that both strengthened and protected the hull. We have defined the mouldings on the outside as rubbing strakes. They are placed so that they stiffen the hull but are also located where the hull rubs against the wharf edge when moored. This protects the hull exterior against damage in the same way as modern plastic boat fenders. In the Lovund boat there are documented seven rubbing strakes. They have different lengths, from 887 to 4420 mm. The rubbing strakes are fastened to the boat planks with treenails that appear to go through both the planks and frames. Nails have also been used. On the inside of the boat the gunwale has been reinforced with stringer mouldings. Four pieces of rubbing strake mouldings have been recorded.
The vessel has been repaired multiple times.
Planks were used to patch cracks and leaks in the hull. Between these were placed pieces of wool textile and caulking materials such as animal hair, plants and moss mixed with tar. The main caulking between the boat planks was twisted animal hair mixed with tar. Moss was also observed in some locations. The use of moss is interpreted as secondary, and a result of maintenance when the vessel was in use. The planks have also been covered with tar. The overlapping elements of the boat were caulked multiple times, something that is to be expected over the period that the boat was in use.
The investigation shows that the boat has had substantial damage to the bottom of the hull, which was caulked with textiles and patches in the form of thin, short planks and barrel staves. An indeterminate part was also made of birch. Both pine parts and the birch part are interpreted as being added at a later point in time, as the entire vessel was originally built of oak. It is also likely that the vessel was originally caulked with animal hair, and that plant fibres and wool textiles covered with tar were used later to keep the boat seaworthy.
Degradation of the organic material began before the boat was covered with sand, and it is expected that some of the construction elements were removed or disappeared at this time.
A good example of this are solid pieces of timber such as the rudder and crossbeams, that except for one certain and one possible fragment of a crossbeam, were missing. Unless the boat lost its rudder in a shipwreck situation, this should have been present. The keelson is also missing, a part that would have contributed to documenting the location of the mast. The mast and rigging are very rarely found in archaeological contexts, something that contributes to relatively restricted knowledge about rigging details from the medieval period. However, we can confirm that the boat had a square-rigged sail.
We also found some vague indicators that make it possible to say something about the rigging. The lack of a keelson, and fragmentary condition of many parts, provides few definite clues. The four fastening points on the rubbing strake moulding x261 are interpreted as evidence for fastening the shroud and supporting the mast from the side of the boat. Similar shroud fastening points have been observed on several vessels from the end of the medieval period in Kalmar harbour, Sweden, roughly contemporary with the Lovund boat.