Archaeological site evaluation in the North Sea location Borssele Windfarm III/IV

<p>The project is executed from the survey ship Noordhoek Pathfinder (NHP). The operation is managed by Van Oord Offshore. The ship is equiped with a range of survey tools. Basic equipment is the Triton XLX workclass ROV system, multibeam sonar, subbottom profiler, side scan sonar, magnetometer and crane or grab capable of lifting a 5 ton load or more after rewiring. A BODAC owned airlift system is also installed on board to assist the research. Last but not last a moonpool is built into the ship construction. The ship is quite flexible and can be reroled to accept a range of jobs by switching containers on the quarterdeck.<br>The cannons were successfully recovered and brought ashore for the purpose of conservation.<br>Cannon site E04 was inspected afterwards conform planning to check for any possible wreckage.<br>Visual inspection as well as post survey with an electromagnetic detector and a multibeam sonar did not reveal the presence of any possible wreckage material underlying the cannon position. The results of archaeological investigation of these cannons will be reported separately.<br>The wreck in D06 was examined by preparing a trial trench and by documenting it with the camera’s installed in the ROV. Because of the constant backfill the trial trench in site D06 could not be fully uncovered, resulting in a patchy dataset of the wreck that was positioned between one and two meter below the surface of the seabed. However a coherent image emerged after analysis. The original ship must have been around 5 meters wide and 15-20 meters long. It is assessed to have the characteristics of a coastal vessel, most likely a small freighter. The ship construction elements do not match the proportion of an ocean going vessel or inland vessel. From the construction details could be inferred that the wreck is dated in the nineteenth or early twentieth century.<br>However, this is not corroborated by dendrochronology analysis of the recovered timber elements from wreck D06.</p>