March 2008

Despite the many difficulties associated with working in a busy urban environment the Brunswick Wharf to Osborne Street Cable Tunnel project was successfully completed. The work included marine and land based UXO surveys, co-ordinating plant movement between the various borehole positions, difficult accesses, traffic management, service location and reinstatements. Under the supervision of Parsons Brinkerhoff on behalf of EDF Energy Networks, Fugro Engineering Services Ltd were instructed to carry out a site investigation to aid in a feasibility study to assist EDF Energy in determining their future underground cabling strategy. The work comprised five cable percussion boreholes to depths of up to 45.00m and ten combined cable percussion with rotary cored follow on boreholes with depths up to 55.50m. Three of the combined boreholes were carried out using a jack up barge in the Thames. A number of machine excavated trial pits were also carried out to assist in the design of the surface works of the shafts. The rotary coring was carried out using the Geobore S wireline system to obtain high quality samples of the London Clay, Lambeth Group and Thanet Sands. Core was logged and subsampled on site by an engineer from Fugro.