Concrete Repairs & Cathodic Protection – South Hook Jetty, Milford Haven

jetty repairMarine Jetty Repair

South Hook LNG Company

Principal Contractor
CB&I John Brown

Main Jetty Contractor
Besix-Kier Joint Venture

Specialist Contractor

Contract Value
£8.6 million

Work Commenced
August 2005

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An LNG receiving terminal has been constructed at South Hook, Milford Haven, South Wales. Part of the construction involved the repair and protection of an existing 30 year old jetty facility to provide a further 30 year life. The project included concrete repair and cathodic protection (CP) of reinforced concrete pile caps, prestressed concrete piles and new and old steel piles.

The existing jetty is 1km long, comprising 125 separate support structures. The jetty head is a further 1km in length and comprises five existing berths that will be converted into two LNG super tanker berths.

Freyssinet undertook sprayed concrete repairs and installed CP. The existing structures suffered from chloride contamination which meant that corrosion of reinforcement and damage to the concrete had taken place, and without CP it would continue.

Prior to CP installation, Freyssinet undertook concrete repairs. First a detailed survey was completed and damaged concrete removed by hydro-demolition. Repairs were made using dry mixed sprayed concrete.

Cathodic protection to the concrete was achieved using a titanium mesh anode in an overlay of sprayed concrete.

Additionally, impressed current CP was provided to protect the underwater sections of the concrete and steel piles.

The Freyssinet team combined the skills of Freyssinet Ltd (UK), Freyssinet France and CCSL. Sprayed concrete personnel and expertise were provided by Freyssinet France, CP design and expertise by CCSL, and project management and installation works by Freyssinet Limited. This unique team offered the client assurance of the skills of Freyssinet and the ability to undertake key aspects of the project in-house.