Moving production to a new factory is just one of the measures Vestas took to deliver the Bligh Bank towers ahead of schedule.
In autumn 2009 a challenge faced Mogens Husted Hansen, project manager in the Strategic Projects Department of Vestas Towers. The order for 35 of the steel towers to support the Bligh Bank turbines had been brought forward from 2010 to 2009, and capacity at the factory in Varde, Denmark, was already fully booked.
To deliver on time, Mogens and his team moved part of their production to Vestas Towers’ Rudkøbing factory. They also brought in a new external supplier to join the two existing firms who apply the metal and epoxy coatings which keep corrosion at bay during the towers’ tough life at sea.
“Building offshore towers isn’t rocket science, but people underestimate the time it takes to get everything approved,” Mogens says.
Vestas’ offshore towers are custom-designed for the specific site condition, and this means a lot of work in design, approvals, quality assurance and logistics, as well as the actual manufacturing.
Especially critical to quality in offshore projects is the flange at the base of the tower. This bolts onto a corresponding flange at the top of the foundation, which is typically supplied by another company. “This means that any mismatch would be bad news, but as far as I know it has all gone very well at Bligh Bank,” says Mogens.
Bringing in new factories and suppliers made the whole process more complex, but has paid off well. “We had a firm order by week 32 of 2009, and we delivered the first towers within 18 weeks,” Mogens says. “The hard winter made outside work difficult, and the production staff had to work between Christmas and New Year.”
“But as we say: no tower, no power! I’d like to thank all my Vestas colleagues for doing such a great job in delivering the Bligh Bank towers on time,” says Mogens.
Facts:
Each Bligh Bank tower is 51 m tall and 4.3 m in diameter at the base. Steel plates up to 25 mm thick are rolled and welded to create a tapering tube, to which are attached top and bottom flanges.
At the bottom of the tower are the main access door and the entry point for the power cables. On the Bligh Bank towers, an innovative design has simplified the manufacturing process: Vestas has combined the door and the cable entry into a single large steel assembly 60 mm thick.
