Vibrational testing of oak from the warship Vasa
The warship Vasa sank in Stockholm harbor 1628 on its maiden voyage. After the complicated salvage in 1961, the Vasa Museum now displays a world unique and well-preserved ship from the 17th century. However, the oak wood has deteriorated due to chemical processes while resting in the clay on the seabed. This has led to increasing deformations of the hull due to the weight of the ship and a new support structure is needed.
Dynalyse AB was therefore recently assigned by the Vasa Museum to determine stiffness properties of full-size oak planks from the ship. Using vibrational techniques, the modulus of elasticity and rigidity were measured with high accuracy on planks that were removed from the ship. The results indicated a substantial weakening of the approximately 400-year-old material compared to new oak. This data will be important input when designing the new support structure within the project “Support Vasa”. The high level of competence and experience within Dynalyse AB regarding vibrational grading of structural timber was an important factor behind this assignment.
The collaboration with the Vasa Museum and the skilled staff was excellent – this National Treasure is in good hands!
Link to the Vasa Museum: https://www.vasamuseet.se/en