Foynes Port Repeat Survey Results

Geomara undertake regular multibeam surveys in order to accurately monitor the condition of berths and pockets at Foynes Port. The port are very keen to monitor the condition beneath the jetties and to monitor any slumping or siltation which may occur.

Grid model of the Results of the July post dredge survey.

A major programme of suction dredging was undertaken at the port in July 2018. The post dredge multibeam survey when compared with surveys undertaken in February gave a very clear indication of the effectiveness of the dredging.

Grid model of the post dredge survey results along the west jetty. The 10.5 m contour is highlighted in red.

The point cloud images, charts and profiles produced by Geomar based on the survey data proved invaluable to the harbour master in planning future campaigns. The dredging successfully reduced the bottom of the berth tight against the fender line of the jetty.

The harbour master at Foynes requested a condition survey at the berths and turning circle at foynes in November this year. The results were compared to the previous pre and post dredge surveys and clearly revealed some slumping along the fender line.

The profile comparisons of the three surveys showed the slumping and a gradual sedimentation within the berths since the end of the dredging campaign. The sharp edges of the latent suction dredge tracks clearly visible on the post dredg survey have been rounded and smoothed.

Profile comparisons along the west jetty at Foynes. 0 on the x-axis equates to the fender line. The black line represents the pre dredge survey data and the maroon line represents the post dredge survey undertaken in July.

The ability of the Reson T50R multibeam system deployed for the surveys to see under the jetty and up the slope inside the fender line allows a clear comparison between the surveys and the resultant difference model graphically highlights the slumping.

Difference model clearly showing the slumping which has taken place since the post dredge survey in July.