The Mast Wreck
– abstract of the field report
by Torleif Nilsson
Five kilometres east of Gamla Oxelöund at the Bråviken Bay, Swedish East Coast,
there is a remarkable wreck on ca 30 m depth. The wreck site is in a military area where
no anchoring or diving is permitted to the public. The wreck was discovered by the author
during a 1992-94 wreck survey project.
Diver at the top of the standing mast. Note the pulley block still in
position. Photo: Torleif Nilsson.
Unique wreck in the Oxelö archipelago
Even by the high standards of preservation in the Baltic Sea, this wreck is unique in
several aspects. This 17 m long and 5 m wide carvel-built ship stands deeply embedded in
the bottom sediment with no apparent list and seems to be totally untouched since its
sinking about 250 years ago. The ship was two-masted and the main mast is still standing
in its full length. On the badly worn deck, there are several fallen-down rig details,
near their original locations. Most of the ship’ interior is covered by mud, but in
the stern section, clay pipes, wine bottles and other domestic items have been observed.
The
Mast wreck offers unique opportunities to provide detailed knowledge about
shipbuilding and life onboard an 18th century merchant ship. After the sinking,
the ship seems to have landed almost undamaged on the sea bottom. It is not unlikely that
the complete rigging remained more or less intact for some time, before it rotted away,
and the rigging fell straight down on the deck.
The typical Baltic wreckfind has either been smashed at the sinking or damaged later by
the forces of nature or human activity. Many wooden wrecks in the Baltic Sea look more
like piles of planks, where the parts often have been stirred around.
In this case we have instead a wreck that seems to be more or less untouched and where
most of its information is preserved. This is manifested by the standing main mast. Indeed
it is worn by time and several parts have fallen off, but this process has been very
gentle. All loose parts remain close to their original locations.
Already at the first dive in 1994, it was obvious that this wreck needed an immediate
investigation. It was well preserved but at the same time looked very fragile. It seemed
to approach a stage of accelerating collapse.
At the stern we located several 18th century wine bottles.
Photo: Torleif Nilsson.
Computer generated models
During 1994-96 extensive video and photo documentation was made as well as measuring of
the wreck. From this data a three-dimensional model was created using the CAD programs
Pro/Engineer and Pro/Mechanica. Based on the CAD model and the video footage, the skilled
artist Göran Ullrich made several accurate images. These images have been a great aid,
considering the limited visibility at the actual site. The drawings are quite detailed,
but still preliminary. Several measurements may change during the course of investigation.
A simplified 3D CAD model, made from measurements as well
as video and photos. By Torleif Nilsson.
1997 fieldwork
During 1997 a permit was given to take samples, for dating the ship.
Several wood samples, pine and oak, were taken for dendrochronology analysis. One glass
bottle was brought up from the group of 13 bottles that lay openly in the stern section.
The initially planned probing of the hold was cancelled following soundings with a thin
rod. This indicated that the content of the hold was too compact to penetrate.
Clay pipe salvaged in 1997 for dating analysis. Photo:
SSHM.
Analysis
The dendro analysis has been made by Alf Bråthen, bottle treatment and conservation by
Ingrid Hall Roth (Vasa Museum), bottle analysis by Lars Westergren, and clay pipe analysis
by Arne Åkerhagen. They have all helped the project by doing this free of charge. The
analyses suggest that the ship was built and sank during the first half of the 18th
century.
Just aft of the hold two pumps are sticking up. Photo: Torleif Nilsson.
1998 fieldwork
During the summer of 1998 the documentation continued. Also, the main mast was braced
and stabilised with new rope. This was important not only for the wreck but also for the
divers’ safety. A permit was also given to salvage the remaining visible bottles,
since they are fragile and at risk of being crushed by future collapsing parts of the
ship.
Future work
There is no lack of things to do. But presently, the main task is trying to finance
future investigations, as well as the cleaning, conservation and analysis of the items
already salvaged. One of the remaining questions is the cargo. Is it possible to tell
without excavating the entire hold? Is there a way to measure the shape of the lower hull
which is embedded in the bottom?
In the stern, where the living quarters were, remains of the galley can
be seen. Photo: Torleif Nilsson.
The Mast Wreck Association
This association was founded in 1997 as a means to find sponsors for the further work.
So far, support has been given by the cities of Nyköping, Trosa and Oxelösund, as well
as the county of Södermanland. We have also been given generous help by Crimson AB,
Södermanlands Nyheter, Södermanland County Museum, SSAB, Fastighetsbolaget
Nötknäpparen i Nyköping, Sandvik Handtools AB, Sjöfartsverket, and Oxelösunds hamn
AB.
Torleif Nilsson
abstract of the original report in Swedish,
translated by Per Åkesson, Feb '99
Sonograms
Sonogram 1 (bow upwards) and sonogram 2 (stern upwards) by Sture Hultquist. |
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