Hydrographic inspection of historic quay walls in Amsterdam
Report by Pantelis Karamitopoulos
This report discusses the suitability of hydrographic survey techniques to inspect the historic quay
walls of Amsterdam. The hydrographic surveys were carried out at two quay-wall segments at the
Houtmankade and Overamstel areas during the second half of July 2021. Both quay-wall segments are
representative of the historic quay walls in the city centre. The main scope of the surveys was to
acquire high-resolution 3D point cloud and visual datasets in order to distinguish the wooden piles of
the quay walls and to measure the free length of the piles, the pile diameters, the cross-pile distances
and the cross-beam (kesp) dimensions. For this scope, the multibeam echosounder and the acoustic
camera techniques were utilized under a multi-scale approach. First, the multibeam echosounder was
used to acquire high-resolution 3D point clouds below the waterline. Second, the acoustic camera was
used to perform real-time measurements of the quay-wall structural elements and to acquire detailed
visual information focusing on the piles, cross-beams and decks of the inspected quay-wall segments.
Post-processing of the point cloud and visual datasets including filtering, subsampling and
segmentation operations enabled to distinguish the quay-wall piles and to measure the dimensions of
the quay-wall structural elements with high accuracy.