Scope: To raise the existing 65m tower at Tournafulla wind farm with a proposed 10m extension.
Date: January 2010
Equipment: anemometers, vanes, temperature, pressure, humidity, SCADA system, crane, excavator.
Requirements: Our client wanted to use an existing free-standing metmast (Tournafulla 65m high) rather than erect a new mast at a new windfarm (Rathcahill) 3km away. However they needed wind measurements at a greater height (75m). Therefore there was a request for extending the existing Tournafulla metmast by 10m.
This extension of the mast however was not a simple operation. After carrying out the design appraisal report and calculations, the existing 65m tower was found to be unsuitable for adding a 10m extension on top. The mast legs would be overstressed, deflection on top will be 2.2m and the raft foundation will not meet soil condition and overturning criteria.
Solution: We gave the client two options. They choose the option of maintaining the mast as a free-standing structure as was. A new section was installed at the bottom of the mast, onto the existing concrete base. The mast was then lowered by crane to ground, to fit the new section. The wind sensors were removed to protect from damage as the mast was laid out on the ground.
Obelisk Impact: Using experienced Project Managers we completed the work to ensure strict compliance with all Quality, Health & Safety and Environmental obligations and requirements.
The landowner was pleased with condition of the completion site, which necessitated re-instating and levelling soil banks and replacing farm gates etc.
The project was completed as planned, although there were some delays in concrete pouring due to the severe weather around this time. The (original) sensors were reconnected and the Tournafulla system is operating normally.