Page 28 - Loss of the VOC Retourschip Batavia, Western Australia, 1629

Timber recording Eachindividualpieceoftheship'sstructurewastagged
in situ. The tagging system used a coded number, with a prefix letter to identify the type o f component (i.e. frame, strake, etc.) A rather crude system which was used during the initialstages oftherecovery work was rationalized, as the structure became more complex, into a coded system based on the layer within the structure. Six basic layers were distinguished in the side of the ship and these were coded alphabetically from the top to bottom, correspond- ing to the inside (top) to the outside (bottom). The numbers differentiated timbers, in particular layers. Thus:
A. Knees, decking, deck beams and everything on top of the ceiling
B. Thin skin on top ofB
I
B. Ceiling
C. Frames
D• Thin skin on top ofD I
D. Inner layer of strakes
E. Second layer of strakes, lying below or on the
outside ofD
F. Sheathing
T. Stem structure
As the work progressed towards the stem, the size and
complexity of the structure increased, resulting in some problems in identification. For example, the decking was not immediately recognized and was simply given an A prefix. This occurred with several other components at the stem, resulting in the A numbers being rather muddled.
Figme 16. Breaking up concretion using a geological hammer Ceiling was discovered towards the stem and was num-
and a short-handled sledge hammer.
Additionally, a contour map of the wreck site was made by running a series ofseven parallel lines 3 m apart, along the long axis of the site. Depth measurements were made at 1 m intervals along each line with a Bourdon-type depthgauge.Theresultsweretransferredtotheplanofthe wreck site, from which contours at 1 m intervals werecon- structed.
During the recording of the ship's structure, underwa- terpromes across the timbers were made. These were used to check the accuracy of, and for comparison purposes with, the prome recording results produced from the profiles of the curvature of the ribs (see below). The underwater system consisted of driving two metal stakes into the seabed on either side of the timbers. The strakes were arranged so that a wire stretched between them at rightanglestothelineofthestrakes.Thewirewaslevelled using a carpenter's spirit level. The vertical distance from the wire to the joint between two strakes was measured using a carpenter's level to obtain the vertical. Horizontal and vertical distances were recorded, and the results plot- ted to give the curvature of the hull. This technique was extremelydifficulttouseunderwaterbecauseofthesurge. The results were not as accurate as the profiles taken from the curvature of the ribs, which were recorded on land.
bered BO to B11. The frames which were encountered at the north end of structure were numbered consecutively from Cl to C46 which was next to the fashion-piece. The buUocks of the frames were not scarfed together so that, in some cases, frames had three separate buttocks. These were denoted by C-Eas~ C, and C-west
The first layer of strakes encountered was given a D code, and this applied to all s!rakes attached to frames. At the north end of the site, the strakes were numbered DO to 06.Astheexcavationprogressedtowardsthestem,strakes further to the east and west were encountered. Strakes to the east were given negative numbers; at the widest point the s!rakes ranged from D-8 through DO to D12.
The second layer of strakes which statted directly under D5 ran to the E.
Underlying the D and E layers was a thin layer of pine sheathing which was coded F. It was not clear how the sheathing was made up, as it was in quite poor condition.
We used tags ofwhite, 2 mm-thickPVC sheet 100 x 50 mm square. Code numbers were wriUen on them with a black, water-proof ink, felt-tipped marker. The tags were aU3Ched to the timbers with galvanized roofing nails.
As each layer of timber was uncovered, it was tagged according to the above system, photographically recorded (see below), raised and returned to the base camp. There, each individual piece of timber was given a registration number, identified and then stored in sea-water holding
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