The expanded boat- an experimental archaeological building project

The expanded boat was built by boatbuilders Hanus Jensen and Rasmus Budde JensenThe Slusegård boat, dating to around the year 100, was found on the island of Bornholm.

Hanus Begins by making a 1:5 model which will demonstrate what happens to the boat's form, when it is expanded. Experience has shown that this is a useful tool to have when building in full scale.
After ca. 10 minutes in the steam chest, the model's sides are expanded. Here, they check to make sure that the shape is correct.

The original Slusegård boat was made of oak and we bought a 154 year old oak log - with an astonishing lack of sapwood.

Using the model as a reference point, Rasmus and Hanus begin to work on the boat in full scale. The boat is formed based on the reconstruction drawings and the experiences gained while making the 1:5 model.

The boat is dug out by cutting sections across the log and then cleaving out large pieces of oak. This is the most effective methodology. The exterior of the boat must be finished first, before the interior can be adjusted. he boat now has the correct thickness.

The finished sides of the boat are no more than 1.5cm thick at the top and 3cm thick at the bottom of the boat. It is important that the sides have an even thickness, otherwise problems can arise when the boat is expanded.

The boat is laid in water until the boatbuilders are ready to expand it. 
Hanus checks its stability. You can clearly see how the sides incline inwards across the middle of the boat. It is here that the boat will be expanded

A month later, the boat is taken up out of the water again. The tannins in the oak have given the boat a darker colour.

In order to support the hull during expansion, a piece of wood is inserted at the gunwale at either end of the boat. Rasmus shapes a section of root from a spruce tree, until it fits to the boat. The root is fitted. We hope it will help prevent the timber in the ends of the boat from splitting

The full scale boat will be warmed over fire, to make it soft and workable. 
Boatbuilder Morten Møller helps with expanding the boat.

The boat is placed between two fires, so that it can be warmed up from both sides. The boat is heated for half an hour, as hot as is possible without the timbers igniting. When the timber is suitably warm, the expansion can begin.

Here is the finished boat. Now we just need to insert the frames. Moulds for the frames. The frames will be made from crooked oak.