Floating Sheet Pile Gate – Tilbury 2, London

Subsea retaining wall

To construct a new CMAT berth at the Tilbury 2 (a new terminal for the Port of Tilbury), TWD developed a method to install a subsea 330m-sheet pile wall. To accomplish the installation, we designed a floating sheet pile gate.

For this project, a solution that allowed piling across tidal levels was required. Therefore, we designed the sheet guiding structure in between two rows of floating modular pontoons, which also served to provide access for personnel, irrespective of the tide. To continue piling below water, a wider pile interface toward the aft end of the pontoons allowed the larger follower structure to pass through the gate. Our marine team performed stability and relative motion assessments of the two pontoons.

For this project, TWD also delivered a tubular pile gate to install the dolphin structures. The gate is hydraulically actuated longitudinally on rails on the deck of a floating barge and outrigs over the side shell. We designed a simple opening interface that allowed the piles to be side released.

Project highlights

• Opening the gate around the hinge and floating to the next position easily repositions the designed structure
• It keeps its position using side-released-temporary spud supports or against previously installed long sheet piles
• The piling operations required less handling on-site and safely increased the piling rate
• TWD also designed a barge-mounted dolphin gate that can install multiple tubular piles