Wednesday, February 8, 2017

The Story of the Wasa - Part 4, Deterioration and Salvage



It took over two weeks for word of the sinking of the Wasa to reach the King Gustavas Adolphus in Poland.  His response was to demand the guilty parties be punished since the cause must have been “imprudence and negligence.”  The captain along with other surviving officers and crew were brought before an inquest.  The shipbuilders were also interrogated.  In the end no guilty party was found.

                                                                1734 illustration of salvage methods 

Within three days of the wreck a salvage operation was begun to raise the ship.  Two ships were positioned above the wreck.  Strong lines were attached from these surface ships to the Wasa.  The surface vessels were filled with as much water as was prudent.  The lines were tightened.  The water was then pumped out causing significant lifting force on the wreck.  This was initially successful in getting the Wasa setting on its keel, but they were unable to free it from the mud.  The salvage attempt was abandoned.


Three decades later a project was mounted to retrieve valuable items from the Wasa.  In particular more than 50 of the Wasa’s 64 guns were retrieved.  Also sculptures and other wood was salvaged.  During this process part of the deck was torn apart to gain access to the guns. There were no known further attempts at salvage until the twentieth century.



Two of Wasa's knightheads 

During more than 300 years at the bottom of the Stockholm harbor the Wasa experienced a significant amount of deterioration.  Iron bolts had been used to attach the beackhead, the sterncastle, and all of the ships sculptures.  This iron quickly rusted away and the items it held fell into the mud or onto the decks.  Only the largest cast iron objects survived – anchors, cannon balls, etc.  Wood, cloth, leather and other organic items fared better.  Objects which fell into the mud were protected from currents and sediments.  Some of the paint on sculptures in the mud survived.  Soft tissue was consumed by fish, crustaceans, and other sea life.


The most destructive force, however, was human activity.  As mentioned above much of the deck planking was removed to get to the cannons.  The Stockholm harbor is a busy shipping lane and it is clear that several ships dropped anchor on the Wasa demolishing part of the ship’s upper structure.  Construction debris was frequently dumped in the area and some of it landed on the ship.


                                                      Wasa breaking the surface after 330 years 

In August of 1956 after several years of searching an amateur archeaologist rediscovered the Wasa.  An effort was begun to attempt salvage of the ship.  Multiple methods of recovery were explored, but the final method chosen was similar to the failed attempt 330 years prior.  Using high pressure water jets, tunnels were dug under the vessel.  Steel cables were strung through these tunnels and attached to two surface pontoons.  The pontoons were filled with water, the cables tightened and the water pumped back out.  During late summer of 1959 eighteen such lifts were successful in moving the Wasa from its original depth of 105 ft. to a more sheltered area of the harbor 52 feet deep.


Wasa floating on to her concrete pontoon 

The next 18 months were spent preparing the Wasa for the final series of lifts to the surface.  Debris was removed, nail and bolt holes were plugged, the gun ports were temporarily closed off.  During 16 days in April of 1961 a series of lifts brought the Wasa to the surface.  She was towed to a dry dock and floated on her own keel onto a concrete pontoon on which she still rests.




A tall ship model of the Wasa is available for purchase at Ship Models Online



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