Searching for the boundaries of the universe

Various crane views in the cleanroom

Isometry – View of the synchronized cats

Cleanroom crane in operation

Cleanroom crane in operation

With an extraordinary cleanroom crane, the specialist Altmann has taken on a pivotal role at the Faculty of Natural Sciences and Technology at Maastricht University in a uniquely global project.

The initial situation was tricky, and the requirements were quite demanding. But who would expect that the construction of a cleanroom for a gravitational wave observatory to explore the inner workings of the universe would come with trivial demands? After all, as part of the research project "ETpathfinder" led by Professor Stefan Hild, a scaled model for the Einstein Telescope (ET) is being built. This, in turn, is part of a planned, cryogenically cooled, triangular underground laser detector with three 10 km long arms, which will theoretically be capable of exploring the universe back to the Big Bang.

The "ETpathfinder" test facility is currently being built in a former transport hall in Maastricht, which has been extensively converted into a vibration-isolated cleanroom over the past few months. According to experts, this research project will become a valuable infrastructure for further gravitational wave research and the technology for their detection.

So, it's no small feat they have undertaken. And nothing that should encounter project delays due to failures. The company Altmann, specialized in cleanroom cranes from the Bavarian Albaching, quickly came into play and implemented an impressive custom-built system within a few weeks: 22 meters span, a twin lifting device with two extremely precise, fully synchronized hoists, connected as master/slave, each with a load capacity of 2,000 kg.

On the Limits of Physics

The challenge of installing a crane of this size into an already completed cleanroom was surprisingly solved by Altmann with a shared bridge girder with a mounting trolley, much to the astonishment of the Maastricht researchers. However, for the two company managers, Achim and Robert Altmann, this was nothing that kept them awake at night. Following their motto "only physics shows us the limits," they had already demonstrated with their team on another project that they push all possibilities in the interest of the customer. They proved that even such a mega system can be assembled in parts within the cleanroom and installed and commissioned on site—while maintaining hygiene standards.

In the Maastricht project, the crane will initially be used to bring components for the ET test setup and the entire laboratory equipment into the ISO 8 cleanroom. However, the crane was designed for ISO 6. Later, it will be used to carry out the necessary modifications to the experimental setup. The flexibility and precision of the two hoists, each with a 4-ton capacity, will undoubtedly prove useful here. Because most of the modifications to the experimental setups and the research equipment that must be mounted and dismounted are unique, requiring very precise and slow connections or disconnections.

Regarding this project, Robert Altmann emphasizes in an interview with Cleanroom Online that the company's high manufacturing depth and comprehensive service offering have proven to be a blessing. They would never have been able to meet the tight schedule if they had relied on suppliers or subcontractors. In fact, Altmann (almost) does everything themselves—from planning, static calculations, mechanical and electrical design, control systems, programming, and commissioning of all software, to complete manufacturing including gears and final expert approval. "We offer cleanroom technology from start to finish, fully thought out," says the company boss, not without pride.

Set a High Standard Yourself

But even technically, Altmann's cranes are a special feature. First, there's the low overall height, which allows optimal utilization of the available room height and also saves space in the Maastricht building. And then there's the high standard set by Altmann itself for cleanroom cranes, which acts as a benchmark in this market segment. Because it is no longer enough to simply build a cleanroom crane that meets ISO 14644-1 requirements. Operation, cleaning, maintenance, and retrofitting of components or functions must also avoid contamination.

Therefore, Altmann cranes are powder-coated throughout, providing smooth, scratch-resistant, and easy-to-clean surfaces. All cables, gear assemblies, fastenings, electrical components, sensors, as well as the hoist with electric strap are neatly "encased" in housings. The materials are chosen and combined to minimize abrasion and outgassing. The duplex load straps are completely maintenance-free, wear hardly, and only minimally stretch due to a special material pairing. Conventional textile straps, on the other hand, first stretch measurably in length before the load is actually lifted. To prevent abrasion on the rotating load hook, it is made of stainless steel or coated with a hard nickel plating, according to DIN 15400.

In terms of load capacity, Altmann recently made headlines with its world record of two cleanroom cranes with 2 x 15 tons, but the company also offers smaller versions starting at 500 kg.

Although the Maastricht project will primarily focus on Einstein's theory of relativity, the success of the cleanroom crane project is already absolute today. Achim and Robert Altmann would hardly be satisfied with less. Their credo fits perfectly with the overall concept of "ETpathfinder": "The cleanroom tolerates everything, except compromises."

We can look forward with anticipation to the results that the Maastricht research project will uncover with the help of Altmann's cleanroom cranes.