- Project: Moray East Windfarm
- Principal contractor: VolkerInfra
- Project lead: David McNair, Regional Engineer
- Key benefit: 23.0m clear span open excavation enabled by our T700 brace
Introduction
To facilitate the installation of a new offshore windfarm, three cofferdams were required on Scotland’s North coast to form transition joint bays, connecting offshore and onshore cables together.
An open span excavation was critical to the project to provide sufficient working room to complete the cable jointing works.
The Solution
MGF’s design and technical sales representative worked closely with the site team to understand their requirements and identify hazards around the excavations that would need to be considered within the temporary works design, including cranes and cable pulling plant. Due to shallow bedrock, a two-frame solution was adopted, with the lower frame removed after casting a concrete base.
To provide a clear open span to each excavation at 23.0m x 8.5m and a depth of 3.85m, MGF’s Regional Engineer David McNair specified a top frame combination of MGF’s T700 and 406UC braces with 305UC along the width and a lower frame of 254UC with cross struts and again 305UC along the short edge of the excavations.
The top frame combination consisted of MGF’s T700 brace and 406UC brace along the length, and 305UC for the width to provide the required open span of 23.0m x 8.50m sheet-to-sheet. The lower frame consisted of 254UC brace and two 200 Series cross struts, with 305UC along the width of the excavation.
The Verdict
Developed to allow open spans of up to 30.7m, MGF’s T700 brace was the perfect fit to allow VolkerInfra to form the transition joint bays that will eventually allow offshore renewable energy to be transferred on shore.
