Rothesay Ferry Terminal Scour Baffle

Lochshell Engineering were appointed in May 2018 by Argyll & Bute Council to be the Principal Contractor for the design, manufacture and installation of a new scour baffle screen and bracing system at the existing ferry terminal in Rothesay, Isle of Bute.

Rothesay ferry terminal, Isle of Bute, is a busy ferry terminal, fish quay and harbour which also provides pontoon moorings for pleasure craft. An overnight berth is provided on a separate pier adjacent to the ferry berth for the roll-on roll-off ferry. The ferry operates from a linkspan berth which impaired the area where the scour baffle was installed.

The new scour baffle screen was commissioned by Lochshell Engineering to protect the long-term integrity of the quay wall at Rothesay. The new screen has minimised the effects of the propeller wash which affected the masonry quay wall located beneath and to the rear of the suspended deck of the ferry berth.

The majority of site works was carried out during the night to minimise disruption to the ferry services and other harbour users.

Lochshell engineering has successfully completed the installation of the new scour baffle screen. The works involved the following:

Design of a new wave screen, supporting members and bracing system.
3D survey carried out to gauge the alignment of each pile. The survey showed all pile sets are of different alignment, meaning a bespoke solution was required for 15No pile sets.
Tolerance was incorporated into the design and fabrication to consider further misalignments and potential error in survey information.
Fabrication in-house of all members and connections. A clamping system was used to provide additional tolerance. Bolted connections were used where possible to reduce site welding, both on and below water.
A total of 120 tonnes of steel was fabricated and galvanised.
Delivery of components from Lochshell to Clydebank via road haulage, onwards transportation to Rothesay via Multicat vessel.

On site works involved the following:

Installation of temporary scaffold to allow for above water works.
Installation of bracing and associated components.
Installation of the wave screen and associated components.
Steel components were lifted over the edge of the pier using Lochshell Engineering’s 360-degree telehandler.
Above water installation was carried out by Lochshell Engineering. Below water installations, including welding, was carried out by a sub-contracted dive team.
Post-works surveys were carried out to obtain record data, including below water survey and laser scan.

Works completed August 2019.