Raked Piling Gate – Twelve Quays, Liverpool

Opposing rakes and limited space

To install a cluster of four raking piles for the Twelve Quays Jetty in Liverpool, TWD designed a double-layered pile gate that supports itself on previously installed vertical piles. The proximity and opposing angles of the raked piles posed geometric and loading challenges in the design, but using two modular jack-up barges, the drill rig could approach the pile gate and reach its maximum drilling radius from either side of the cluster. As the drill rig tracks over the deck, a cantilevered frame in the pile gate design supports the demanding tracking and drilling loads.

Our designs made sure the piles were pitched and driven within the required installation tolerances while at the same time supporting the drill rig.

Project highlights

• Structure designed with features to be easily cut and removed after installation
• A functional approach to the design
• Quick and cheap fabrication
• With slight alterations to the design, portions of the pile gate were also used as support for concrete formwork, extending the effectiveness of the design
• Interface with modular pontoon barge connectors