Research has shown that the timber in the Vasa’s hull has weakened due to chemical degradation in the wood. Interdisciplinary research also shows that there is a clear link between the wood’s chemical status and its mechanical properties.
The museum carpenters have long noted that the ship’s timbers are deforming, and regular position measurements show that deformation of the hull is continuing. The ship is also leaning slightly towards the port side. This inclination is increasing over time, making straightening of the ship imperative.
The Vasa therefore needs a new support that can decelerate movements and deformations, thereby ensuring long-term preservation of the ship. The Vasa is currently braced the same way as a sailboat would be, on keel blocks with supports along its sides. The current cradle dates back to the 1960s. It was reinforced in the 1990s, but not sufficiently. Current research on the specific properties of the ship will be used as the foundation of work to build a new support.
The research project “Support Vasa” was conducted 2012–2016 in partnership with and under the leadership of the Department of Applied Mechanics at Uppsala University. In 2018, the project entered a new phase, focusing on project planning and design of an improved support system.
A new support will ensure long-term preservation of the Vasa. It must ensure that the hull retains its existing shape and distributes loads in a manner that is gentle on the ship. Hull movements and the risk of cracking must be minimised. In the future, the ship will be supported both externally and internally. The Vasa will be given an internal skeleton that will slow down movements of the hull.
One of the challenges of the new support is that it must not obscure the ship more than necessary, nor hinder accessibility around the ship or encroach on the exhibition area.
A critical part of the project is straightening the ship so that the masts are as straight as possible. This will be a difficult and delicate operation. The straightening work will probably be carried out once the entire support, both internal and external, is fully built since this will be the gentlest approach for the ship.