A new machine dimension

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energy

A new machine dimension for a valued customer

Henning Albrechtsen, owner of the Danish family-owned company HACO A/S, had been looking forward to the “Christmas present” of a Droop+Rein portal milling machine from Starrag for a long time, and he was not disappointed, as it arrived in good time at the end of November 2023 and was put into operation after the holidays. The special features of this 870-ton colossus include its XXL size and its unusually large basement section across two storeys.

“This saves users time and money, as they need fewer machines and undergo reduced setup times.”

Fabian Schwarz, Head of Project Management of the Business Unit Large Parts Machining Systems (LPMS)

“Integration of both processes enables production of complex workpieces with great precision and efficiency.”

“Never before have we built such an extensive tunnel system for a production plant; it is reminiscent of ancient catacombs and even I have never seen something like this anywhere else,” explains Hubert Erz, Senior Consultant Sales/Renewables at Starrag. “However, this expensive and elaborate investment for our core customer facilitates service access and day-to-day collaboration using this new machine.” Laying the foundation involved processing 850 cubic metres of concrete and 100 tons of steel: thanks to its generous dimensions across two stories, it provides operators with easy access to drive elements and other components of the Droop+Rein portal machine. In any case, the basement section immediately garnered a positive response from the production team. Henning Albrechtsen states: “The foundation forms the base for the machine tool, and its stability and design help determine the level of precision that can be achieved with the machine. In addition, the tunnel system within the foundation provides good access to all relevant machine assemblies and thereby ensures optimal ease of servicing. Furthermore, the ‘cellar’ enables many units to be positioned underneath the upper edge of the hallway, which contributes to a substantial reduction in noise levels.” However, the tunnel system is not the only innovative approach that the CEO of HACO – a second-generation family business – has taken. The company already owns five Dörries vertical turning lathes, which have helped it grow to become one of the leading Danish contract manufacturers of gigantic components for the wind power sector and offshore industry.

Danish teamwork: XXL rotor housing for the future of wind power

However, even a job shop specialising in XXL components cannot afford downtimes. As such, HACO has already needed to increase the maximum swing diameter of its vertical turning and boring mills several times. Their next major order, from an international leader in the area of wind turbine manufacturing, involves completely new dimensions. This order focuses on the next generation of offshore turbines with rotor diameters that now exceed 220 metres, designed for an output of 14 megawatts with their direct drives. HACO and a Danish partner have been contracted to produce components of correspondingly large size. This involves machining front and stator sheets and brake discs, alongside other primarily welded components and multiple steel rotor housings with weights of between 50 and 90 tons and diameters of almost eleven metres.

In order to approach this XXL future with confidence, Henning Albrechtsen decided to purchase a pair of machines designed to handle these ever-increasing dimensions. The first machine, a gantry portal milling machine with a 100 kW milling head and 2×111 kW master-slave main drives, represents the combination of two distinct areas of expertise for Starrag. Erz: “We integrated components from the Dörries product area into a Droop+Rein milling machine, thereby combining turning technology with milling technology.” The machine has a clearance of 12,600 mm in between the stands, the gantry axis travels over a distance of 14,000 mm, and the tool slide allows a maximum stroke of 3500 mm.

“We integrated components from the Dörries product area into a Droop+Rein milling machine, thereby combining turning technology with milling technology.”

Hubert Erz, Senior Consultant Sales/Renewables

Complete machining improves productivity

Assembly and commissioning were performed by a Starrag team led by Fabian Schwarz, Head of Project Management of the Business Unit Large Parts Machining Systems (LPMS) with the product areas of Droop+Rein, Dörries and Berthiez. Even though large machines are part of his day-to-day work, this new creation with its hydrostatic bearings and rotary table with a weight of 180 tons and a maximum load capacity of 350 tons is still something quite special. One benefit of the machine is that it combines milling and turning in a single machining centre. “Integration of both processes enables production of complex workpieces with great precision and efficiency,” Schwarz explains. “This saves users time and money, as they need fewer machines and undergo reduced setup times.”

Stationary portal, moving table

The table of the second machine is movable. The machine delivered at the end of 2023 features a moving portal, whereas this configuration has a stationary portal and a moving table. Erz: “This special design, created primarily for turning processes, has received new support with the new tool holder constructed and constructed by the Bielefeld team for combined milling/turning operations.” In terms of dimensions and weight, the 6-axis portal turning machine is number one, and only the master-slave main drive (output: 2 × 36 kW) is somewhat larger. The plant has also gained a larger workpiece swing diameter, which was able to be increased from 13,000 mm to 15,000 mm thanks to the moving table.

Regardless of this, HACO can completely machine all workpieces on both machines, meaning that they can be used as ideal supplements to and replacements for one another. This pair of machines also features highly precise positioning across all axes – the two machines can achieve electronically controlled positioning in the micrometre range even for metre-long travel paths.

However, how does a company that produces components for wind power approach the issue of sustainability? As HACO states on its homepage: “As a supplier to the energy sector, with a focus on green energy, HACO intends to contribute to the lowest environmental impact in the manufacturing process.” This approach on the part of the Danish company has been confirmed by TÜV Nord, which has certified its environmental management system according to the strict requirements of EN ISO 14001. As such, new machines are always fitted with a sophisticated enclosure with supplementary extraction unit, which protects employees against noise and aerosols (mixtures of air and very finely dispersed solid and liquid particles).

HACO has now taken a further important step to protect the environment in how it operates its new XXL machine pair: Its operation site is the SM Industries A/S industrial estate in Rødekro, which is a company with whom HACO has worked closely for many years. This leading supplier of steel components for wind power applications was a subsidiary of the steel trader Euro-Steel DANMARK A/S until recently, and previously delivered welded blanks via heavy goods transport to the HACO plant in Barrit to undergo mechanical finishing all the way from the town of Rødekro, which lies 100 kilometres to the south. These components, mainly sets consisting of a rotor housing, front sheet, stator sheet and brake disc and weighing multiple tons, were then transported all the way back again from Barrit to the port at Aabenraa on a specially designed fixture.

Internal transport instead of heavy-duty transport

SM has provided its long-standing partner with a hall for the XXL machine pair, which HACO then excavated to a depth of up to six metres for the extensive foundations. This has eliminated the previous need for typical overland heavy-duty transport and replaced it with quick and environmentally friendly internal transport. And the Rødekro location is near to the Baltic Sea ports of Kalvø Havn and Aabenraa, from which the jointly manufactured plant components can be transported for assembly in the customer’s coastal plants with much less environmental impact. This is also perfectly in line with HACO CEO Henning Albrechtsen’s viewpoint: “There has been close collaboration between the companies HACO and SM for a long time. For this new project with its particular challenges, we worked together to find the most cost-effective and sustainable solution. Using an existing production hall meant that there was no need to construct new buildings. And since we are located on the same site – next door to each other, in other words – transport paths between blank manufacturing, heat treatment processes and mechanical processing were reduced to a minimum, which has cut costs substantially. All of these benefits and the proximity to the port eleven kilometres away have contributed to a sustainable solution and are in accordance with the green principles of the wind industry.”

His 87-year-old father Johan also responded positively to this result. “When he established HACO, he invested in high-quality machines with automation right from the start. The first vertical milling machine was already equipped with an automatic pallet changer,” states Henning Albrechtsen. “This was later followed by a flexible manufacturing system with two linked vertical milling machines. Something like that had never been seen before in our region. As such, we are continuing to follow this innovative and future-oriented approach and developing to meet the challenges of the times. My father has visited the first machine twice so far, and is already looking forward to the arrival of the second.” This machine is still in Bielefeld, and will begin its journey to Denmark in the first quarter of 2024.