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Port Users - Harbour Maintenance

Dredging in the Harbour

Dredger View 1 Dredger View 2
Dredger

A dredging contract was awarded to UK Dredging Company Limited and their Suction Dredger "UKD Dolphin" commenced work on 8 September 2003. It trailed a suction arm along the seabed and took approximately one hour to load its 1,000 cu. metres capacity. The spoil was then taken out to the authorised spoil ground, four miles out in Dublin Bay, and deposited in a blanket action as the ship slowly moved along. A second vessel, the plough dredger "UKD Sea Lion" joined the work a few days later, its initial task was to haul spoil out from alongside the berths into the path of the suction dredger. Later the "UKD Sea Lion" acted as a bed leveller to ensure that any remaining "High spots", from the main works were removed so as to provide a level, dredged area, all work was completed by Wednesday, 24th. September 2003.

Dredger View 3
Dredger

Captain James Carter
Harbour Master
September 2003

Dredging Past & Present

Once again the harbour requires dredging and the main fairway is to be taken to a depth of 6.1 metres (Depth before tide added) in 2003. The estimated cost of the programme is € 0.5 Million and a rigorous vetting programme has to satisfactorily completed before official sanction is received for the both the removal, and dumping, of the dredge spoil. This includes a chemical analysis, and material composition of the spoil, and particulars of the dumping area - in accord with modern environmental safeguards embodied in national legislation.

It has always been necessary to carry out dredging in the harbour and this affected the OPW, (Office of Public Works), to permanently base dredgers in the harbour. Their last two dredgers were scrapped in the mid-1970s and since then work has been carried out by various contracted, dredging companies.

Dredgers "Saxifrage" and "Sisyphus"

The attached photograph (Courtesy of Mr. Noel Brien) shows the last two OPW vessels, Bucket Dredger "Sisyphus" and the Grab Dredger "Saxifrage", both built 1908, alongside each other at Traders' Wharf. The triple expansion steam engine of the "Sisyphus" is now housed in the National Maritime Museum, Dun Laughaire and other than other than a few artifacts in the harbour offices, everything else went to Hammond Lane, Dublin for scrap.

These old dredgers were capable, over time, of removing copious quantities although they are small and underpowered craft when compared to modern vessels. The OPW 1913-14 Annual Report stated that, "upwards of 54,000 tons of material was dredged from the harbour bed and deposited at sea." By comparison the impending dredging, by suction dredger and plough tug, is expected to remove somewhere above that order in a continuous working period of three weeks.

Jim Carter, Harbour Master

Dredger Images

Dredger "Oatfield" Dredger "Oatfield"

Additional Reading