2 The raising of the VAL7 watership
In May 2007 some wreckage material surfaced in the river entrance Buiten IJ near Amsterdam during dredging operations (fig. 3). The location was marked and operations continued as demands for a deep commercial shipping channel had to be met.
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Figure 3 Wreck location VAL7 east of Amsterdam in the shipping lane (
Waldus 2010
).
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Figure 4 This multibeam image clearly reveals the shape of the hull. The fish well area in the middle is divided into two sections, and the bow area is located at the bottom of the image. The dark square left bottom is the spot where dredging stopped (
Waldus 2010
).
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The unknown wreck was reported immediately as it may have historic value, but clearly was an obstacle in the future shipping lane. Authorities subsequently ordered an onsite dive inspection and a geophysical survey to be executed. Multibeam sonar images revealed the contours of what appeared to be a watership (fig. 4).
Divers observed that the wreck with an overall length of 17.5 metres was well preserved under a layer of ballast stones. A sample from the wooden structure was taken for dendrochronological analysis onshore, and revealed that the watership must have been constructed after 1585. Further analysis of ceramics and a coin found during the dive inspection indicated that the ship was wrecked around the year 1600. General policy is to preserve a high value wreck like the VAL7 in situ, but in this case the obstacle had to be removed from the shipping lane. It was decided to raise the wreck and bring it ashore for detailed study. In September 2009 a salvage vessel was contracted, equipped with diving gear, pumps and hoses for sediment removal, a sonar and a 200 ton crane. The divers used surface supply equipment with built-in communication and video. Ship archaeologists, hydrographic surveyors and diving technicians made up the excavation team, with an underwater archaeologist in charge.
The divers first removed the ballast stones by hand from the wreck, they amounted to around five tons of jagged football-size boulders located in the holds fore and aft of the fish well. Some elements of the original ship’s inventory were retrieved from between the boulders, their exact locations being plotted on the multibeam image of the wreck site. With the ballast stones gone, a layer of sediment was uncovered that settled in the wreck over time. This layer was systematically removed by pumping the sediment upward through a sieving construction on the salvage-vessel deck. Small finds like fish bones could thus be separated from the sediment, while find-spots were immediately marked in close liaison with the diver through the communication system. Finally the site was fully recorded with a sector scanner, revealing that the hull was now free of sediment and stone.
It was assessed that the wreck would break up during lifting operations as the construction had lost much of its structural strength. This would defeat the purpose of recording and analysing the construction in detail once it was lifted ashore. Therefore the decision was made to carefully cut the wreck into three parts with an underwater chainsaw. First the divers used a suction pump to carve out trenches under the ship structure at predetermined sawing locations. Next the wreck was cut into three parts. Finally trenches were carved out under each of the three construction parts to rig the slings for lifting. The slings were connected to a lifting frame that prevented the construction from crumbling under its own weight while being lifted onto the salvage vessel. The three parts were lifted one by one and placed on a bed of sand onshore near the site for detailed study (fig. 5). Upon completion of the research the VAL7 wreck was repositioned in a new location underwater making it accessible to sports divers (fig. 3).
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Figure 5 The VAL7 wreck lifted ashore for documentation purposes (
Waldus 2010
).
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TheVAL7 has a sharp hull shape underwater, just like the other watership wrecks found in Flevoland. This is an exception to the general observation that ship types indigenous to the Zuiderzee area are flat bottomed (Petrejus 1964, 148). The function of the ship is clearly illustrated by the finds of inventory and cargo. A number of rounded net weights of stone in the holds indicate a function as fishing vessel or trawler, towing large fishnets across the Zuiderzee (fig. 6). The unusual high concentration of fish bones of flounder in the fish well (Waldus 2010, 41-43) tells us that fish was kept alive for the market. The wreck shows the typical watership layout of a centrally located fish well split into two by a bulkhead, and storage space fore and aft of the fish well. Judging from the remaining dimensions, its length to width ratio approximates 3 : 1, and its overall length must have been around 20 metres. The reason for the fish not to swim out of the fish well after the sinking of the ship may have been a cover blocking the entrance to the fish well. Other explanations may exist.
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Figure 6 Watership as trawl net fishing vessel. In the drawing the ship is offloading fresh fish into a small boat at Amsterdam roads for the local market. The long pole on the side, the ropes and net weights (rounded stones) dangling off the side are part of the fishing equipment. (Detail from a pen drawing by Ludolf Backhuyzen c. 1660 (collection Maritime Museum Amsterdam).
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The VAL7 appears to have the same robust construction as the other wrecks from Flevoland. However it has a flush hull while many older wrecks have a lap-strake hull, and it seems to have been longer than the other wrecks. It is built on a keel plank where a keel beam was expected as in the case of other contemporary wrecks. More constructional differences with other shipwrecks were observed. So the question is where the VAL7 shipwreck actually fits in the total picture. The answer must be found in the total dataset, that is subject to scrutiny in the next paragraphs.