Gwynt y Mor, Ventilation Retrofit, Trepanning 200 and 100 dia holes

Due to the unforeseen hazard of gas build up below the airtight platform in the offshore wind towers, the client required a ventilation system installed. This required several large penetrations through the deck and wall of the tower, the largest of which was 200dia through 70mm thick. Drilling of service holes or tack welding location plates to secure equipment was prohibited. We were challenged to complete all machining within 2 days

The equipment needed to man handle-able to make transfers from the supply vessel down into the machining location as easy as possible and had to run off 100V 16amp supply. Reekie used its own design of trepanning tool with our MFT machine driven by an electric motor. Following optimisation through trials we managed to get the machining of the 200dia hole through 70mm think down to 45mins, using a single man operation

Each tower consisting of two 200dia penetrations, two of 100 dia penetrations, were completed within a couple of shifts – including mob and demob of equipment onto tower, marking off hole positions and creating a post machining report. A total of 80 off towers have been modified to date