The
remains of a plank-built boat were discovered by the Poznan Archaeological Museum
expedition in ąad by the Warta river in October 1981. The wreck was found at
about 1.5 m outside the fortification ring 1 m below the actual ground level.
The boat from ąad is the first wreck of a plank-built boat built on a T-shaped
keel with the bottom and boards overlapping that was found distant inland. The
wreck measuring 8.5 m in length and about 2 m in width was located parallel
to the embankment line with its bow facing the east. Presently the wreck is
reconstructed at the exhibition of the Polish Maritime Museum in Gdasńk.
There
had been seven strakes to either side of the keel. All seven had survived in
the starboard side, while only three strakes were preserved on the port side.
The end of strake 6 on the port side was not nailed to the sternpost; instead
it was scarfed to the fifth strake. The strakes were assembled in the lapstrake
manner with a land of 4.5 - 5.5 cm wide, and fastened with treenails 1- - 1.2
cm in diameter. The wedged treenails were driven from outside at an interval
of 8.5 - 9.5 cm.
The hood ends of the planks were fastened to the sternpost with iron nails.
The strakes were made of two or more overlapped planks joined through scarfs
secured with treenails. A total of 16 frames, numbered 1 through 16 from the
stern to the bow, were preserved. They consisted of straight floor timbers with
futtocks alternating with half-frames. No fastening was observed between futtocks
and floor timbers. The floor timbers were fastened to the hull with pine treenails,
one for each strake. The naturally curved half- frames were not fastened to
every strake in the hull. No fastening was observed between frames and keel.
On the average the spacing between frames was 40 - 46 cm.
The inner structure was reinforced by a birch stringer notched over the floor
timbers. Some of the half-frames were set over the stringer which was notched
at these joints. At the sheer strake the hull was reinforced by a rubbing strake
made of ash wood (Fraxinus sp.). Three additional elements were fastened to
the hull from the inside in the stern quarter . Made of naturally curved branches,
the longer arm of each knee-like timber was fastened to the inner side of the
hull, while the shorter arm extended over the sheer strake and the rubbing strake.
The vessel could have reached a length of 10.70 m and a breadth of 2.35 m.
In the first study concerning the artefact in question the determination of
the region and century of the boat's origin is described as one of the most
important issues of the investigation concept concerning the artefact from Lad.
On the basis of the analysis of the boat's structure and interpretation of the
entire finding it was indicated that the boat originated from the end of the
medieval period - perhaps the 13th century. The boat age measurements taken
by the Laboratory of the Physics Institute of the Silesian Technical University
in Gliwice with the employment of the C-14 method gave slightly different results.
The conventional radiocarbon age was determined as 1120+70 BP (GD-2230), and
the calendar age as 970 AD or 900 AD where the final error in respect of each
of the specified dates may be estimated as + 90 years. The results have been
adopted in the literature concerning early medieval Slavonic boatbuilding.
In 1996 seven samples from the planks and the central keel part were taken for
dendrochronological analyses. Following examinations carried out at the Dendrochronological
Laboratory of the University of Mining and Metallurgy in Cracow the construction
of the boat was determined to fall in the years following 1125 AD. The obtained
growth ring sequence on the basis of the samples from the boat is 234 years
old and represents the period of 891-1115 AD. The actual year of cutting the
trees determined by the dendrochronological method is not included in the C-14
dating range.
The keel of the Lad boat was made entirely from one oak trunk and survived in
the length of 7.2 m. The sample taken from the keel central part shows that
the element was made from trunk pith parts. The Lad wreck keel was given a shape
close to the letter T in such a way that the pith centre went centrally through
a plane between the keel arms and beam.
The analysis of board cross sections visible during sample taking permitted
determining another regularity. The examined planks taken from all strakes are
turned with their pith parts towards the hull's outside and the external parts
come under the overlap of the next strake. The probable reason for that is that
the keel and the front and back parts of bottom planks are exposed to heavy
friction over the bottom. The higher planks of the upper hull part are placed
in the same way, the pith part turning inwards. It is because wood has the highest
ability to bend in the outer parts of the mother trunk.
In order to determine the place of origin of the wood from which the boat was
made the obtained average curve was compared with chronologies from southern,
central and eastern Poland. The mentioned ring growth sequence from Lad shows
the greatest similarity to regional chronologies from the area of Wroclaw (t=7.3)
and Opole (t=5.9).
It is thus indicated that the wood used for building the boat is of Lower Silesia
provenance. The boat must have been built inland, most probably in the area
of Wroclaw.