Tower bolting flanges

Bolting flanges are used at the interfaces between the tower and the nacelle yaw system at the top, the foundation at the base, and sometimes between tower sections.

Description of Manufacturing Process
Typically made from forged or rolled steel rings. Turning, and sometimes milling, are then used to ensure concentricity and tight surface tolerances. Finally, drilling and boring are used to create precise bolt holes.

Description of Supply Chain
Tower manufacturers usually buy forged or rolled and machined bolting flanges from specialist large-diameter rolled rings suppliers (Euskal forging, Flanshechenwerk Thal). The flanges are then welded to the tower sections at the tower factory.

Scottish Opportunity
Relevance to Scottish Supply Chain: Low

CNC machining is typically undertaken in house by the tower manufacturer, so little opportunity exists for external suppliers to support.