Oak planks from a shipwreck from
the 15th century are cleaned with a
pressure cleaner. The wreck was dis-
covered in the Bay of Greifswald, or
Greifswald Bodden, by underwater
archaeologists who accompany the
construction of the NEL gas pipeline.
The planks are kept in water tanks
until proper preservation. Rust from
disintegrated iron nails precipitates
and covers them in red.