The withys holds the rudder in place on a viking ship. Withy works like a rope that goes through the rudder and in through the side of the ship, and then the withy is fastened around the frame inside the ship. The root of the tree sits on the outside of the rudder and are used as a barb on the wicker, which is holding the rudder firmly on the ship.
The tree is twisted
Withy is made of a young birch tree with a diameter of 5 cm just above the ground and with no large branches on the first 2.5 metres of the trunk. On one side of the tree, the roots are cut about 20 cm from the trunk. The tree is pushed over while the remaining roots are still intact in the ground. Next the tree is twisted, starting from top and working towards the roots. This causes the longitudinal fibres in the trunk to break away from each other and the tree can be bent. When the trunk has been twisted to about 20 cm from the roots, the remaining roots are cut and the withy is ready.
Time for a new withy?
A withy can, depending on how good the tree is and the length of the voyage, last for 7 days of sailing. The crew has several withys with them when they go on a trip. When the withy begins to wear out, it is replaced. It is easiest to change the withy in port, as it requires a lot of space to change the withy.
New steering system
Terms like 'Viking ship' and the 'Nordic, clinker-built ship' covers a very large range of types of ships and boats built at various times and at different locations in Scandinavia. This type of ship has a particular type of steering system; the side rudder, which was attached to the starboard side astern (the right-hand side of the ship’s sailing direction).
A new rudder system was introduced in northern Europe in the 12th century. This was the stern rudder which was attached to the stern. However, in Denmark the side rudder was not replaced by the stern rudder until the beginning of the 14th century.
Watch the movie about the withy harvest
The film - with English subtitles - demonstrates the processes involved in producing and using withies to secure side-rudders on Viking ships.