report to the trustees of the honor frost foundation by...
TRANSCRIPT
Report to the Trustees of the Honor Frost Foundation
By Dan Mirkin, Department of Archaeology, Tel Aviv University
Having been awarded a grant by the Honor Frost Foundation for the research of
the so called 'Apollonia Port', and having accomplished the field (sea) work for
which the Foundation had generously awarded the said grant, I take the liberty
of presenting my report.
1. General
The so-called 'Apollonia Port' or 'Military Harbour', located at the foot of the
Apollonia-Arsuf Crusaders' castle, about 2 Nautical miles north of the modern
city of Herzeliya, is approximately 33 meters wide, in the east-west direction,
and about 80 meters long in the north-south direction, (fig.1)
The so called Port has constructed walls or breakwaters along its northern and
southern ends, and a rock-reef to the west. Its four cardinal points are:
1. North-West Corner 32°11'45,18" N
34°48'21,12" E
2. South-West Corner 32°11'42,45" N
34°48'22,35" E
3. North-East Corner 32°11'44,52" N
34°48'22,27" E
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4. South-East Corner 32°11'42,04" N
34°48'21,53" E
As I have already described in the application submitted to the Honor Frost
Foundation opinions differ as to the true nature of the Site: was it a real port or
harbour? Was it just a small mooring basin for small craft? Or, as some
scholars claim, was it just an installation designed to prevent an approach from
the sea to the kurkar1 cliff on which the castle itself was erected.
Dr. Eva Grossmann is one of the scholars who pioneered the research of the
'Port' which was the subject of her PhD dissertation.2 However, among many
other observations, her work included an artist's impression of the 'Port' with a
number of ships moored therein, a description that has, indeed, defied
imagination. The site which was studied in the present work which, for the
purposes of this report I shall refer to as 'Port' or 'Site', was silted, and full of
rubble, including whole sections of walls which fell from the castle. The main
purpose of the study was to identify the archaeological characteristics of the
site. Therefore we excavated underwater three trenches by water generated
dredgers. During the work it became clear that a geo-morphological study is
required, taking into account the sea-level changes since the 13th
century3. We
have ,therefore, surveyed by water jetting probes the majority of the site,
including the alleged entrances.
2. Logistics
The Port is located at the foot of the cliff. However, in order to protect the cliff
against erosion by the sea waves, in the winter of 2009 huge boulders were
1 "Kurkar" is the common name for fossilized sand stone, or calcareous sandstone.
2 Grossman, E. Maitime Investigation of Tel-Michal and Apollonia Sites, Ph.D. Dissertation --
Macquarie University, 1995.
3 Toker, E., et al., Evidence for Centennial Scale Sea Level Variability during the Medieval
Climate Optimum (Crusader Period) in Israel, Eastern Mediterranean, Earth Planet. Sci. Lett.
(2011), doi:10.1016/j.epsl.2011.07.019
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placed on the narrow beach, to the south of the port, west of the castle, making
approach by foot extremely difficult and hazardous. As for the approach from
the north – there is no way to reach the beach by car, so there is no possibility
for overland transport of excavation equipment such as water-pump, dredgers,
or dive gear (e.g. air-tanks) and so forth. This obviously, prescribed the need to
find a solution of transport by sea. The dredge water-pump, which weights
approximately 250 kg, was installed on a wooden stage on a rubber boat,
(fig.2),
and sailed to the Site from the marina of Herzliya. The operation was done very
early in the morning when the sea is relatively calm as the boat, being very top
heavy, was not really designed for such a work, and any beam wave could have
caused a capsize. At the entrance to the Site the outboard engine of the boat
was raised, due to shallow reefs, and she was rowed in. The rest of the
equipment, air-tanks, dredgers, hoses pipes, dive gear, office supplies, food etc.
was transported on a very flat motorboat which was 'walked' into the Port,
through the narrow entrance in the reef (fig.3).
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In some works this reef was interpreted as part of a breakwater, and, actually,
acts as such to some extent. Except during the first stage of installation and,
later, the dismantling of the camp, the motorboat remained out of the reef and
air-tanks and provisions were sailed into the Port on a kayak, (fig.4).
Electricity and water were brought down, by long hoses and cables, from the
Apollonia National Park located at the top of the cliff, and a tent was erected
for a guardian who remained on the site during the entire operation.
3. Equipment
- Angus Fire LD 1800 water-pump used for operating
dredges and water-jetting.
- Many sets of ventury dredgers, hoses, pipes, crates and
one set of water-jetting.
- chests for transporting rubble and stones.
- Fifteen sets of dive gear and diving suits.
- Equipment for underwater documentation: drawing,
recording and photography.
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- Measuring equipment.
- Office supplies and dive log.
- Equipment for setting up a camp: tent, table, kitchen
equipment.
- Miscellaneous tools and equipment.
- Supply motor boat and rubber boat.
4. Work performed
General:
The work was divided into two main topics: studying of the breakwaters, on the
one hand, and studying the seabed, on the other hand. A total of 119 dives were
performed under supervision of the Maritime Workshop of the Leon Recanati
Institute for Maritime Studies, University of Haifa. The work included clearing
of stones and rubble, excavation of trenches, water-jetting and recording of the
constructions on the site
Seabed:
The first stage involved, mainly, clearing stones and rubble which littered part
of the bottom of the Port, most of which fell down from the castle over the
years. This was done to create areas of clear seabed that could later be
excavated, (fig. 5).
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The stones, generally ashlars often measuring about 40 × 30 × 25 centimeters,
were collected into crates, dragged under water and then deposited outside of
the northern wall.
When a substantial area located in the north-western part of the Port was
cleared of heavy rubble and stones, the excavation commenced, employing two
dredgers. It was decided to first try dredge a deep trench in order to examine
the foundation of the northern wall or breakwater, and the western reef and
when the trench has reached the depth of about 1.5 meters divers were
instructed not to excavate under the wall so as to avoid danger of collapse.
After the foundation of the breakwater was examined, it was decided to extend
the trench eastward, toward the shore. At a later stage the trench was extended
southward and deeper.
As much of the area of the Port was covered with large wall sections of the
castle, and since the excavated trench proved that the bedrock is much deeper
than was first considered, it was decided that better knowledge could be gained
by performing water-jet probes in many areas of the Site, and measuring the
depths of the seabed (fig.6).
The jetting was preformed with 2 meters intervals between each probe, in order
to establish the depth of the port. A total of 74 probes were performed, some
going so deep that the probe itself, about two and a half meters long, was sunk
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completely into the sea bed. Some probes hit rocky bottom at a shallow depth.
The probes were performed in many axles, (marked in red lines on fig. 7),
and, at each probe, the depth of the seabed under the water was marked, as
well as the depth of penetration of the probe. The probes have easily penetrated
the bottom of the Site which has often consisted of soft kurkar surfaces.
Northern and Southern constructions (Breakwaters?)
After excavating the trench, an easier access to the base of the northern
construction became accessible. Measurements of the construction and the
ashlars, of the northern wall were taken and drawings were made, as, for
example, a drawing of a part of the northern wall, or "breakwater", (fig. 8).
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Measurements and drawings were made also of the southern wall, the remains
of which are much less substantial. Photographs above and underwater were
taken, mainly of the trenches, indicating the depth thereof below water level,
(fig. 9).
Many underwater photographs of the northern wall were also taken, as, for
example, fig.10.
When the trench at the base of the northern wall reached a certain depth, one
could notice a "clean" course of newly uncovered stones, as opposed to the
upper courses covered by sea-fouling, (fig. 11).
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5. Results and preliminary conclusions
Finds
Some pottery fragments, including a spout of a Gaza type jar of the 6th and 7th
centuries AD and some other ceramic fragments found (mostly medieval in
date) were not very significant. A modern piece of jewelry as well as a modern
Israeli coin were found about 1.5 meters under the sand slightly to the east of
the north western corner of the Port, which proves that the sand silting the Site
kept moving and was not stationary.
Breakwaters (??)
Until the research was carried out it was considered that the Site was
surrounded by man-made breakwaters, and that the western seawall has
disappeared, but that there was a foundation for such a wall. Having carefully
studied the western wall, which is constituted by a long reef positioned roughly
in the south-north direction, it is now certain that it is part of a natural rock.
However, the builders of the Port have, apparently, cleverly used it and built
walls roughly in the east-west direction at both ends of this reef, between its
both ends and the shore, and have positioned a watch tower at the corner where
the southern breakwaters meets the natural reef.4 On the reef itself there
appears a narrow shallow trench, (fig. 29), very probably man-made, too
narrow to serve as a basis for a wall, and its purpose should be the subject of a
further study. The walls are built from kurkar ashlars, often in the fashion of
'headers', presenting the narrow face of the stone to the sea.
The lowest layer of the stones constitutes a protruding ledge, slightly wider
than the upper part of the wall. However, it is not certain that this protrusion
constitutes a ledge and, perhaps, the whole construction was wider, and part of
4 The direction of the northern breakwater is 210°–130°, and that of the southern breakwater is
260°–80°.
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it, above the 'ledge' disappeared with the years, leaving a ledge-like wider
section.5
The northern wall is built on a soft kurkar ramp. This may help to uphold the
theory that the Site or 'Port' was deeper then thought until today, and that the
builders found the need to create a ramp and build a stone breakwater at the
upper part so that it could withstand the waves.
Depths
It was generally thought that the Site is too shallow to have been anything but a
basin that can be used only in a calm sea, which is quite rare in the open coast
of the Eastern Mediterranean. The probes and the excavated trench prove this
to be wrong, and the average depth – except where the probe hit rocks (or
sunken building stones), some of them were deep and some at the seabed level.
The average depth of the water was approximately 90 centimeters,6 and if,
indeed, the depth of the water was as deep as the probe went in and the trench
excavated, then theoretically small to medium sized vessels could have been
moored in the Port. The trenches, some reaching down to the harder rock, are
between 1 and 2,6 meters deep below the water level.
However the question of the shallow entrance, still needs to be addressed.
Entrances
When we sailed with the rubber and supply boats in order to establish the
camp, the outboard motors had to be tilted up, to preserve the propeller, and the
boats had to be 'walked in' by man-handling them through the entrance on the
south-western corner. This shallow entrance most certainly precludes the use of
the Site by large vessels of any kind. However, a small boat, (or, maybe, even a
small galley??) could be 'walked in' or rowed in, during exceptionally calm
5 Similar construction in larger and smaller stones is evident in the castle itself.
6 The water depth measurements were carried out at low tide. However, in this part of the world,
the difference between high and low tide rarely reaches 40 centimeters and this would happen
rarely, and only during Proxigean Spring Tide, which occurs once every one-and-a-half years.
The difference between high and low tide during the research period were approximately 40
centimeters. The tide table for local waters at the relevant period is shown on fig. 33.
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sea, the depth of the water above the reef being about 60 centimeters at
medium tide. The supply boat had to be walked out, (fig.12).
Further works
We also intend to use a geodetic surveyor in order to establish a total station
map and incorporate it in a GIS data base.
We intend to take rock samples out of the trench existing on the reef which
constitutes the western "breakwater", (fig.13)
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and have them chemically/petrographically tested for cement residues. If such
are found it might indicate that a man-made wall was built there, with the
trench serving as its foundation. This may provide additional proof that the
"Port" was artificially protected in order to enhance its performance as a
mooring basin.
We also intend to employ a geodetic surveyor and perform total station
measurements in order to include all the recorded remains in the GIS site map.