Following on from the recent Breakwater Project Review, contractors Boskalis Westminster mobilised at the end of July for the last stage of the Cowes Breakwater build, which will be completed in October 2015. This involves a final reshaping of the breakwater’s gravel core, bringing sections into profile before applying layers of small rock that act as a filter to prevent the gravel migrating out of the core structure. Following this, a rock armour layer consisting of 300-1000kg rocks will be installed to provide long-term weather and wave protection. A total of around 45,000 tonnes of rock will be brought from Cherbourg in France and transported by barge to Cowes.
A modified Exclusion Zone is now in force, see Local Notice to Mariners No 26(T) of 2015. The main change to the Exclusion Zone is the extension north to No. 2 buoy, which marks the northwest corner of the Exclusion Zone. The reshaping of the breakwater gravel core has required the removal of the five yellow special mark beacons on the breakwater; permanent navigation marks will be installed on completion of the works.
A temporary dock has been constructed on the northwest corner of the breakwater (see photo above) to facilitate the mooring of the rock barges. The first rock barge is expected in Cowes this week when the placement of rock armour will commence. Approximately two rock barges are expected to arrive per week and will remain on station for around 18 hours at a time before departing the Exclusion Zone.
The rock barge will be offloaded by excavators and shovels on the western end and northern side of the breakwater. Excavators located on the breakwater will position the rocks working anti-clockwise, starting on the southern face working to the east and then back along the northern face to the west, bringing the breakwater to its final profile and finished appearance.
The process involved for the discharging of rock from the barge may occasionally necessitate contractors Boskalis Westminster operating during night-time hours. CHC is working with contractors and the Isle of Wight Council Environmental Health to ensure that any noise and light emissions are kept to an absolute minimum.
The Commission is extremely grateful for the continued understanding and cooperation of local residents and harbour users during this final stage of breakwater construction.
To find out more about the Cowes Breakwater Project, see our website section on Harbour Developments.