The work had to be carried out in a series of stages over a 9-month period, supplying a new cathodic protection system within the columns, crossheads and soffits of the bridge to prevent corrosion and maintain structural integrity. To access the current system, FM Conway used a hydro-demolition technique on 18 individual pillars of the bridge, removing 15mm of the existing structure. Due to the nature of the works, FM Conway designed a bespoke fully incapsulated scaffold for the safety of operatives and members of the public.
Once exposed, FM Conway was able to investigate and address failing elements within the cathodic protection system that had reached their end of life. The cathodic protection technique mitigates the corrosion of the structure by making the surface the cathode of an electrochemical cell. By applying controlled amounts of electrical current to the metal, restricted levels of corrosion within the structure could be achieved, which maximises durability. FM Conway then sprayed concrete over the cabling of the cathodic protection system for 25mm, which was able to effectively cure after a 7-day period.
Louisa Augustine-Fraser, Bridge Engineer at Westminster City Council explained:
"The complexity of this scheme combined with its location highlights FM Conway’s ability to deliver excellence within high profile, challenging environments. The Project Managers displayed outstanding communication skills and ensured the team had a proactive approach throughout, maintaining close collaboration to address emerging challenges and successfully complete the scope of works."