Client
States of Guernsey
Value
£5.1 million
Sectors & Services
Marine Structures Concrete Repair Coatings Corrosion Control Cleaning & Preparation ECI (Early Contractor Involvement) Projects
Guernsey’s marine berths at St Peter Port are a vital component of the Island’s infrastructure, supporting the continuous import and export of goods for a population of approximately 65,000. Located in the Island’s principal harbour, Berths 4 and 6 are reinforced concrete structures subject to severe marine exposure and high tidal ranges.
Following a condition review commissioned by the States of Guernsey, significant deterioration and corrosion risk were identified. A comprehensive refurbishment was therefore required to repair the reinforced concrete, replace deteriorated encasements, and install cathodic protection systems to preserve structural integrity and ensure the long-term operational reliability of these essential port assets.
Services undertaken
-
Early contractor involvement and value engineering support
-
Development of alternative cable routing using hanging cable trays
-
Formation of deck access cut-outs for continued berth operation
-
Design and installation of bespoke steel access structures
-
Hydrodemolition to remove defective concrete
-
Reinstatement of concrete using flowable pumped repair materials
-
Installation of MMO titanium mesh and ribbon anodes
-
Application of sprayed concrete overlays to protected areas
-
Installation of discrete anodes and cathodic protection systems
CRL was appointed at an early stage to work collaboratively with Guernsey Ports and their designers under an early contractor involvement arrangement. This allowed CRL to contribute to the development of the repair strategy, cathodic protection design and construction methodology, while also delivering value engineering solutions. A key element of this process was the design of the impressed current cathodic protection system, where the number of protection zones was rationalised and simplified to achieve cost and programme efficiencies without compromising performance.
The original design proposed routing main cathodic protection cables within ducts behind the dock wall, which would have required extensive excavation and caused significant disruption to port operations. CRL developed an alternative hanging cable tray solution beneath the berth structure, eliminating the need for excavation, reducing risk and avoiding programme and logistical constraints. Further design input included the development of a repair sequence that avoided the need for temporary works and the incorporation of deck access cut-outs to maintain access beneath the berth while vessels remained docked.
Access to the underside of the berths was achieved using a bespoke steel frame structure supported from brackets fixed to the columns. Defective concrete was removed using hydrodemolition, providing controlled breakout in a sensitive marine environment. Repairs were reinstated using flowable concrete pumped into shutters from deck level, ensuring effective compaction and continuity of the repaired sections.
The cathodic protection design, completed by CorroCiv, divided the ICCP system into 30 anode zones. On Berth 4, approximately 4,500 square metres of concrete above mid tide level was protected using an impressed current system incorporating MMO titanium mesh and ribbon anodes, subsequently covered with a sprayed concrete overlay. Below mid tide level, galvanic anodes were installed to the columns, often requiring specialist diving teams. Berth 6 was protected using discrete anodes linked to the main Berth 4 control units. Despite logistical challenges, including shipping specialist materials from the UK and working within a 10 metre tidal range, CRL delivered the works while the berths remained fully operational, demonstrating technical excellence in complex marine concrete repairs and asset management.
“This was a challenging but very rewarding project for the team. By working closely with Guernsey Ports from an early stage, we were able to simplify the design, reduce disruption to the port and keep the berths operational throughout the works. Despite the tidal conditions and logistical challenges of working on the Island, the team delivered high-quality repairs and a durable cathodic protection system that will protect the structures for years to come.”
Steve Jones | Southern Director | CRL
Long-term durability and corrosion control were central to the refurbishment of Berths 4 and 6. The installation of impressed current and galvanic cathodic protection systems provides continuous protection to embedded reinforcement, significantly reducing corrosion risk in one of the most aggressive marine environments. Hydrodemolition ensured high-quality surface preparation, while flowable concrete reinstatement and sprayed overlays delivered durable repairs with strong bond characteristics.
The rationalised ICCP design reduces future maintenance complexity, while accessible cable routing and integrated control systems support efficient monitoring. By combining robust concrete repairs with advanced corrosion protection, CRL has extended the service life of these critical marine structures, reduced future intervention requirements and enhanced resilience. The project provides a sustainable solution that safeguards the operational capacity of Guernsey’s port infrastructure for decades to come.
