Archaeological monitoring of
the dredging for the immersed
tunnel, Oslo, Norway.
2005-2008
A balance between rescuing cultural heritage,
cost and effort.
Tori Falck
Jostein Gundersen
PIANC, 2013-11-20
Constructing the immersed tunnel
The immersed tunnel project 2005-2008
• Tre entrepriser
Havnelageret, Sjødelen, Sørenga
Planning - scoping
• Results of
analyzing core
samples for
dinoflagellate cysts
and spruce pollen.
• Indicating
precence of
sediments from
warm period in
medieval times
(AD1000-1300)
Pockets of ballast sand and flint deep down in
the clay
Coerced situation – from surveying to monitoring
Results from mapping:
1) Acoustic sub-bottom profiler fails to define the contents of the
sediments.
2) Core samples concludes that the sediments consists of layers
from the medieval period.
Conclusion:
1) There is a potential for archaeological remains in large parts of
the tunnel route (shipwrecks).
2) There is no secure evidence to divide between high potential
and low potential.
3) The archeological project is defined as monitoring: Salvage of
archaeological remains emerging in the process of dredging.
Method and basic requirements:
Archaeologists monitor the work on site.
Requirements:
The archaeologist require direct visual and physical access to
all dredged sediments.
The archeologist has the power put the work on temporary
hold if there are finds or to rule out possible finds.
Basic needs and resources:
Enough crew for the continuous monitoring and for
readiness if there are finds.
Dredging: Different situations
Dredging: Different situations
Dredging: Different situations
Custom made sieve
Health and security: Balancing on the barges
Boat: ca.1620
Results: Mass material – harbour finds
Type
Ceramics
Glass
Clay pipes
Shoes
Other
Totale
Keramikk
Sko
Numbers
3811
2072
743
349
185
7160
Glass
Annet
Krittpiper
5% 3%
10%
29%
53%
Results: Boats
Conclusion – Lessons learned
• Best practice is to finish the archaeological work
before the construction work starts
• Adequate mapping should be a piority.
• Achieve a good understanding of the stratigraphic
situation.
• Priority on health and security.
• Good communication between participators in all
chains of the work process.
Boat: 1789/90
Boat: ca 1800
Boat: ca 1840
Boat: ca.1665