Big developments in the transition to new energy sources

When it comes to wind power, Denmark is leading the way: The country now covers 40 per cent of its energy requirements with electricity generated from wind power plants. Specialized Danish companies such as HACO A/S from Jutland have benefited from this situation for years now. Owing to the trend towards larger wind power plants, the company has ordered two gigantic Droop+Rein portal machines from Starrag, in addition to the five vertical turning and boring mills that it already possesses.

An important Danish customer of Starrag orders two Droop+Rein portal machines

“Yes, I’m somewhat uneasy about this large investment, since it far exceeds all the dimensions we’ve been used to up to now,” admits Henning Albrechtsen, the managing director of HACO. He’s standing with qualified engineer Hubert Erz – who is the Senior Consultant Sales Renewables at the Swiss Starrag Group – in the factory hall in Bielefeld, where the two are inspecting the construction progress of the next two machine tools. HACO is a key customer of Starrag, since the Danish job shop already possesses five Dörries vertical turning and boring mills.

With these, HACO was able to develop into a leading contract manufacturer for very large, relatively flat and round components, thanks to the wind power industry in particular.

When the turning diameter grows and grows …

The company has been machining very large components ever since it was founded almost 60 years ago. Nowadays, more than 10,000 tonnes of steel are machined in the Danish municipality of Barrit each year – and the numbers keep going up, since the components required for new offshore wind turbines are only getting bigger and bigger. This also had consequences for the five vertical turning and boring mills, which had their maximum turning diameter expanded to 295 in. (7,500 mm) by Albrechtsen back in 2015. “We modified our machines again to satisfy the demand from one of our customers,” explains the managing director. “This led to the housing around the machine being modified and the tool changers being converted, so that we now have a maximum turning diameter on flanges of 354 in (9,000 mm).”

But is this still sufficient for the latest direct drive wind power plants with outputs of up to 16 MW? The components in demand are namely rotor housings with a diameter of 354 in. or 394 in. (9,000 or 10,000 mm); however, even larger components with a diameter of 453 in. (11,500 mm) mm are under discussion. Consequently, businesses who are looking to keep pace with the wind power industry in the long term need to start thinking about “supersizing” – not least due to growing competition from China in this area. In addition, suppliers increasingly do not just have to process new high-strength steels, aluminum alloys and castings, but also a steadily increasing proportion of composite materials.

Long-lasting machine technology coupled with personal support

Such challenges can only be tackled with the aid of a machine building company that has expertise in delivering quick solutions – and one that offers the latest, long-lasting machine technology necessary for such solutions, along with close cooperation that includes support in service cases. According to Albrechtsen, HACO has chosen Starrag for this role as the company best satisfies these criteria in combination with price and delivery time. The manager of the Danish company also cited the many years of existing collaboration with Hubert Erz as a “significantly decisive factor”.

Starrag therefore received the order to construct two new portal machines for the complete machining of rotor housings, front and stator sheets, brake discs and other components. In the course of the production process at the Bielefeld site, one machine is being developed as a portal milling machine in a gantry design, followed by the construction of the second as a portal turning machine with a third linear axes in the table.

“ Such challenges can only be tackled with the aid of a machine building company that has expertise in delivering quick solutions.”

Henning Albrechtsen, HACO-managing director

“ HACO can completely machine all workpieces on both machines, meaning that they can be ideally supplemented and replaced.”

Hubert Erz, Senior Consultant Sales Renewables at the Swiss Starrag Group

Complete machining in a new dimension

Development is already underway on the gantry portal milling machine, which will allow for powerful turning, milling and drilling of even very large components made from high-strength welded steel and cast constructions through the interaction of the 134 hp (100 kW) milling head with a 2 x 149 hp (111 kW) master-slave main drive. The machine has a clearance of 496 in. (12,600 mm) in between the stands, the gantry axes travels over a distance of 551 in. (14,000 mm), and the ram allows a maximum stroke of 138 in. (3,500 mm).

The dimensions are visibly impressive to Albrechtsen and his employees Christian Hermansen and Tage Friis during their inspection of the first machine, which almost touches the ceiling of the Bielefeld factory hall at its height of 551 in. (14,000 mm). Once it is finally complete, the new creation will weigh around 500 tonnes – as much as 50 bull elephants. It’s not just the size and machine type that are new to HACO, however, but also the location in which the machine is to be deployed. For years now, the company has been working closely together with Valmont SM A/S, one of the world’s leading suppliers of steel components for the wind power industry. Up to now, this company was delivering welded blanks that were transported via heavy goods transport to the HACO plant in Barrit for mechanical finishing all the way from the town of Rødekro, which lies 100 kilometers to the south.

Sustainable logistics for sustainable products

The multi-year customer contract with a renowned manufacturer of offshore wind power plants now required a rethink. HACO and Valmont consequently decided on a more sustainable form of collaboration. The family-run company from Jutland is therefore establishing a subsidiary plant for the two portal machines near Valmont’s headquarters in Rødekro, where the gigantic components for their shared customer can be manufactured without the aforementioned usual transport of heavy goods over land. Rødekro’s proximity to the sea is also a point in its favour. “From here, even gigantic, extremely heavy rotor housings can be transported via ship in an environmentally friendly manner for assembly at the manufacturer of the offshore wind power plants, whose plant is also located near to the coast,” explains Erz, who is supervising the project for Starrag. “This way, we avoid having to use many additional kilometers of heavy goods transports, which would not only obstruct road traffic, but also contribute to environmental pollution.”

Machine no. 1: Deployment in November 2023

The new form of sustainable coproduction will begin in November 2023 with the commissioning of machine no. 1 in Rødekro. At the same time, machine no. 2 – a portal turning machine with a third linear axes and adjustable table – will be constructed in Bielefeld. It has similar dimensions to the portal milling machine, but comes with an additional feature that takes into account the ever-expanding dimensions in wind power plant construction: By adjusting the table, the turning diameter can be expanded from 512 to 591 in. (13,000 to 15,000 mm) as necessary. The portal turning machine is equipped with a 2 × 182 hp (136 kW) master-slave main drive and a 107 hp (80 kW) milling head, and is predominantly designed for turning processes. Erz notes: “HACO can independently completely machine all workpieces on both machines, meaning that they can be ideally supplemented and replaced.”

Visibly impressed by the visit to Bielefeld, it’s not just the managing director of HACO who is looking forward to the new site in the south of Denmark and the deployment of the super-sized pair of machines. Albrechtsen adds: “Our 86-year-old father hopes to experience the commissioning of the two new machines in the new hall for himself.”