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Deal with steel: investigating the wreck of the heavy cruiser Admiral Scheer

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The publication at hand are the proceedings of the 15th International Conference on Archaeological Prospection held between March 28 and April 1, 2023, in Kiel, Germany. The content of the articles ranges from local to large-scale case studies all over the world and from various archaeological times, over methodological improvements, new processing and visualization techniques to a special session on marine and wetland prospection. Thus, the collection of articles summarizes the state of the art of prospection methods for on- and offshore archaeological investigations.
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KIEL-UP • DOI: https://doi.org/10.38072/978-3-928794-83-1/p12 71
ADVANCES IN ON- AND OFFSHORE ARCHAEOLOGICAL PROSPECTION
Proceedings of the 15th International Conference on Archaeological Prospection ICAP 2023
Deal with steel: investigating the wreck of the heavy
cruiser Admiral Scheer
Dennis Wilken 
1
*, Fritz Jürgens
2
, Ercan Erkul 
1
, Wolfgang Rabbel 
1
, Ulrich Müller 
2
1 Institute of Geosciences, Kiel University, Kiel, Germany
2 Institute of Pre- and Protohistoric Archaeology, Kiel University, Kiel, Germany
* Corresponding author: E-mail: dennis.wilken@ifg.uni-kiel.de
Abstract
In this paper, we present, for the first time, a World War II warship imaged underground, in a silted up harbor. Only ref-
lection seismic measurements and electrical resistivity tomography allowed prospecting of the target at challenging
depths from 4 m to 12 m below surface.
Keywords
archaeological prospection; battleship; ERT; seismics; World War II
 Introduction
Individual, large (German) naval units, like battleships,
such as the Bismarck or the Graf Spee, experience great
public interest, while their sister ships are rather un-
known. This also applies to the Admiral Scheer, the
sister ship of the battleship Graf Spee, which, due to a
long and intensive period of service (1934 to 1945), is
one of, if not the most successful, ship in the German
Navy history. One month before the end of the Second
World War, it capsized after a bombing raid on the port
of Kiel. The wreck of the ship was subsequently lled
in with sediments and debris, sharing the fate of the
entire naval harbor basin.
The Admiral Scheer was built as the second of three
armored ships of the ‘Germany’ class at the Wilhelms-
haven shipyard. The ship was commissioned on No-
vember 12th, 1934 and was named in honor of Admiral
Reinhard Scheer. It is noteworthy that ships of this class
were the rst larger German naval units whose hulls
were welded and not riveted and which were pow-
ered using diesel instead of traditional steam engines.
Despite their small size (186 m in length), the ships
were heavily armed with six 28 cm guns. Therefore,
the three ships of this class were known as pocket bat-
tleships. After several missions between 1936 and 1945
the Admiral Scheer was called back to Kiel on March
18th 1945. On the evening of April 9th 1945, during a
bombing raid, ve ‘tall boy’ bombs were dropped on
the ship. The hull on the starboard side was damaged
and the ship capsized in the shallow harbor (Figure
1, top right). In July 1945, British forces began to dis-
mantle those parts of the wreck that were still above
water. Pictures published in the local newspaper Kieler
Nachrichten show that the entire stern as well as the
tank turret and parts of the machinery were recovered.
The harbor basin was then lled in the early 1950s with
sea sand and debris and a drainage channel was dug.
This channel describes a slight curve, which is often
associated with the outlines of the wreck.
Materials and methods
The Admiral Scheer represents an important piece
of German naval and Kiel’s regional history and is a
unique investigation target due to its size and depth of
burial on land within an urban environment.
The presented investigation began with the evalua-
tion of the Allied aerial photographs, showing the ship
overturned to starboard. Later photos show that the
stern and front sections were removed. The preserved
midship area was removed down to the water level.
Based on buildings visible in the photos and still present
72
KIEL-UP • DOI: https://doi.org/10.38072/978-3-928794-83-1/p12
ADVANCES IN ON- AND OFFSHORE ARCHAEOLOGICAL PROSPECTION
Proceedings of the 15th International Conference on Archaeological Prospection ICAP 2023
today, an approximate positioning was obtained for the
remains of the wreck (Fig.1). These remains are expect-
ed to be located at a depth of four to twelve meters. An
object like the Admiral Scheer consisting of steel, with
water lled cavities at such depths, poses a real chal-
lenge for geophysical prospection (e.g. Passaro 2010 &
Passaro et al. 2009), especially on land. Above that, the
accessible area is bounded to the east by a railway and
to the west by the drainage channel. The range of fea-
sible geophysical methods is thus greatly reduced. The
classical methods of archaeological prospection, mag-
netic gradiometry, ground penetrating radar (GPR), and
electromagnetic induction (EMI) were tested but could,
if ever, only scratch at the surface of the wreck. Mag-
netic measurements only show a large dipole anomaly
and are affected by the railway and urban power cables.
Therefore, seismic reection and electrical resistivity
tomography (ERT) measurements were used, offering
the greatest potential to reach most parts of the wreck.
Shear-wave reection seismics were conducted on 19
Fig. 1: Photographs of the ship and investigation area. Top left: the Admiral Scheer (
NH 59664 Naval History & Herit age Command
). Top right:
the capsized Admiral Scheer (
Imperial War Museum
). Below: Map showing the locations of the measuring profile s in relation to the old harbor
basin. The approximate location of the wreck based on an aer ial picture from 1949 (inset of map) is outlined in black.
KIEL-UP • DOI: https://doi.org/10.38072/978-3-928794-83-1/p12 73
ADVANCES IN ON- AND OFFSHORE ARCHAEOLOGICAL PROSPECTION
Proceedings of the 15th International Conference on Archaeological Prospection ICAP 2023
proles with a crossline distance of 5 m (Fig. 1), each
including 24 10 Hz S-wave geophones spaced at 1 m
inline distance in SH orientation. Sledge hammer blows
were placed between the geophones. Data processing
included bandpass ltering, trace normalization and
time gain, f-k ltering, and the creation of time slices.
Time to depth conversion was implemented using an
average shear wave velocity of 120 m/s.
Nine ERT proles were measured with the RESECS2
(Geoserve) multi-electrode system, with 48 to 96
electrodes depending on the prole length. Electrode
spacing was 1m and measurements were conducted
in three congurations (dipole-dipole, Wenner-alpha
and Schlumberger). All proles were inverted with the
same inversion parameters using Res2DInv.
Results
Figure 2a shows the old navy harbor basin after its
relling. The picture shows clear differences in the re-
ll material. Above the wreck, the material appears
coarser in the image, which is also reected in the
ERT data as high-resistivity area. Figure 2b shows
electrical resistivity depth slices interpolated from pro-
les E1-E9. The example slices show the extent of the
coarser lling material in the area of the wreck (down
to more than 3m of depth) and at greater depths re-
sistivities far below the resistivity encountered in the
harbor entrance on E7 (representing soil saturated with
groundwater), which we therefore address as an anom-
aly caused by the wreck.
Figure 3 top right shows an example seismic prole
together with an outline of a cross-section of the tilted
Fig. 2: a) Photograph of the Deutsche Werke Kiel (Koop/Schmolke 1993, 212) and ERT tomogram of profile E1. b) Two example ERT depth
slices representing top material of harbor ba sin filling and wreck remains.
74
KIEL-UP • DOI: https://doi.org/10.38072/978-3-928794-83-1/p12
ADVANCES IN ON- AND OFFSHORE ARCHAEOLOGICAL PROSPECTION
Proceedings of the 15th International Conference on Archaeological Prospection ICAP 2023
ship based on original blueprints. The top left image
shows an exemplary seismic depth slice calculated
from all proles at a depth of 5.3 m, with the position
of the wreck based on an aerial photo superimposed
(dotted line). The reection amplitudes of the seismic
proles clearly reect the shape of the wreck and there-
fore allow its position to be corrected (dashed line).
Discussion
The results show that ERT was able to distinguish the
coarse harbor rell above the wreck from the sluiced
sand around, providing its extent and thickness. In
the deeper parts one low resistive area becomes vis-
ible, probably reecting the wreck’s mixture of steel,
water-lled cavities and debris. This anomaly is slight-
ly shifted westwards in comparison to the seismic re-
sults, probably due to side effects caused by the nearby
drainage channel. In the seismic proles, the reections
coming from the wreck are clearly visible, allowing the
shape of the ship to be traced quite accurately (Fig. 3).
Nevertheless, spatial resolution of both methods is not
sufciently high to distinguish individual parts of the
ship; prole density would need to be increased towards
3D ERT (like in e.g. Rabbel et al. 2015, Günther et al.
2006). In terms of seismic prospection, Full Waveform
Inversion (FWI) approaches could lead to an increased
imaging resolution (e.g. Köhn et al. 2019), probably al-
lowing for an interpretation of the wreck’s substructure.
Fig. 3: Top left: Outline of the Admiral Scheer, based on aerial photographs (dotted line). T he image also shows an exemplary seismic depth
slice and the adjusted position of the wreck based thereon (dashed line). Top right: examplary profile S4 with the depths of the depth slices
and an outline of the wrecks cross-sec tion indicated. Below: two depth slices from ERT (DSL A) and ERT and seismics (DSL B).
KIEL-UP • DOI: https://doi.org/10.38072/978-3-928794-83-1/p12 75
ADVANCES IN ON- AND OFFSHORE ARCHAEOLOGICAL PROSPECTION
Proceedings of the 15th International Conference on Archaeological Prospection ICAP 2023
In summary, the measurements prove that the aeri-
al photo from March 29th 1949 represents the state in
which the Admiral Scheer was buried. Large parts of
the hull and superstructure have been preserved in the
buried harbor basin until today, covered by more than
three meters of sand and debris.
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  • G Koop
  • K-P Schmolke
Koop G, Schmolke K-P. Die Panzerschiffe der Deutschland-Klasse. Schiffsklassen und Schiffstypen der deutschen Marine 4 (Bonn 1993).