Offshore and Inshore survey projects

UXO survey at IJmuiden sealock

T&A Survey performed a large-scale UXO waterbottom survey for the construction of a new sealock in IJmuiden, The Netherlands.


Combined UXO and archaeological North Sea survey

For this project T&A Survey  has mapped the bottom of the North Sea in order to detect possible obstacles for sand mining. These obtacles could be either of archaeological value, like old shipwrecks which by law are required to be handled wih care, or explosives from World War II. T&A has used three different geophysical techniques, which together created a detailed map of the bottom of the ocean: multibeam echo sounder, sidescan sonar and magnetometer.


T&A Survey performed a large-scale UXO waterbottom survey for the construction of a new sealock in IJmuiden, The Netherlands.

Detection in shallow water is often done using a survey boat equipped with several probes on a rack. In deeper waters a so called Fish is used, pulled by a survey boat.The disadvantage of this technology is it’s imprecise positioning and depth measurement. In the seaport of IJmuiden

T&A used an AUV (Autonomous Underwater Vehicle) for detection of UXO. The AUV follows the water bottom and is equipped with a magnetometer probe and Side Scan Sonar. Objects that were suspect according to magnetometer results could be excluded based on Side Scan Sonar results.

For this project T&A Survey  has mapped the bottom of the North Sea in order to detect possible obstacles for sand mining. These obtacles could be either of archaeological value, like old shipwrecks which by law are required to be handled wih care, or explosives from World War II. T&A has used three different geophysical techniques, which together created a detailed map of the bottom of the ocean: multibeam echo sounder, sidescan sonar and magnetometer.

The survey resulted in a list of objects and their GIS coordinates, distinguishing between object of archaeological value and potential explosives. With these results the client was able to determine whether further safety measures or archaeological research were necessary before starting the sand mining acitivities.