Goliath
Mobile flange milling system for large-scale precision machining of tower flanges, monopiles and transition pieces.
Goliath is CNC Onsite’s flagship large-diameter flange milling system designed specifically for precision machining of wind turbine tower flanges, monopile flanges, and transition piece (TP) interfaces. It is the primary machine deployed when sub-millimetre flatness is required on the largest structures in the wind industry.
The machine operates directly at the structure onshore, quayside, or offshore eliminating the need to transport components to a workshop. Goliath achieves documented global flatness results of less than 0.21 mm on flanges up to 7.5 metres in diameter, and guaranteed machine performance of less than 0.2 mm local flatness and less than 1.0 mm global flatness on flanges up to 10 metres.
By replacing manual grinding and shimming with controlled CNC machining, Goliath delivers repeatable, documented results that support reliable bolted connections, reduce rework during assembly, and improve long-term structural performance. The process is particularly critical for offshore structures where even minor flange deviations affect bolt preload, structural fit, and fatigue performance over the turbine’s lifetime.
WHERE WE USE IT
Monopile flanges
Sub-millimetre flatness machining on monopile flanges before offshore installation — eliminating rework and improving assembly efficiency.
Transition pieces (TPs)
Precision machining of TP-to-monopile interface flanges to < 1.0 mm global flatness, performed at the fabrication facility or quayside.
Tower flanges
On-site restoration of tower section flange flatness — no re-fabrication, no transport, turbine stays in the field.
Sea fastenings
Machining of sea fastening and tower stand mounting surfaces on installation vessels and fabrication yards to required tolerances.
WANT GOLIATH ON YOUR SITE?
Tell us the turbine, the challenge, and the timeline. We respond within one business day.