Carrickfergus Marina and Harbour Dredging

Carrickfergus Marina and Harbour Dredging

Contract Value: £767,500-
Consulting Engineer: Doran Consulting
Engineer's Representative: Gavin Nicholl (028 9033 3443)
Client: Mid & East Antrim Council
Client's Representative: Nigel Thompson (028 9336 6666)
Works Completion Date: October 2015

Scope of the Works:

Ashleigh Contracts were awarded this dredging contract as main contractors for Mid & East Antrim Borough Council.

The works comprised maintenance dredging to both the Marina and the Harbour areas with the approaches to each separate shoreline entrance also requiring to be dredged to original design levels.

The dredging was carried out using a spudleg barge with Ashleigh's 42T Long Reach (21m reach) working to bring dredge levels back down to between -1.9m CD to -2.4m CD in the Mairna and -2.9m CD in the Harbour. All dredging had to be carried out in a phased sequence and with stepped dredge levels between different areas of, in particular the Marina. All dredged material was loaded into 335m3 capacity split hopper barges which were towed by Tug to the designated sea disposal area, some 11 nautical miles from site.  

Dredging in the Marina had to be undertaken in 9 phased sequences, each of which required the removal of finger pontoons - with the boats being relocated to alternative temporary mooring positions within the Marina. On completion of each phase, finger potoons were reinstated and the boats relocated to their original moorings before commencement of the subsequent phased area of dredging.

A total of approx. 25,400m3 of dredging and sea disposal was undertaken whilst maintaining fully operational Marina and Harbour facilities during the busy summer sailing season.

Works also had to be carefully planned and sequenced around the tidal cycles given the relatively shallow pre-dredge and post dredge levels for the Hopper Barges and the Towing vessels which drafted in exceeded of 2.5m.      

Areas of Expertise