The stacking cradle system at SÜLZLE Hagmeyer GmbH, a member of the SÜLZLE Group, has been in operation for an impressive 21 years. The steel distributor from Swabia opted to have KASTO's storage technology experts retrofit their bar stock storage system to ensure it continues functioning efficiently for another 252 months. Within 15 working days, the storage specialist worked at incredible heights to replace the drive technology, finishing precisely according to schedule.

When a premium stainless steel pipe leaves Geislingen an der Steige, it likely originated from Hall 9 of the SÜLZLE Hagmeyer GmbH factory grounds. The company has been part of the SÜLZLE Group since 2018 and supplies numerous industrial and craftsmen's businesses in the region with high-quality steel and other metal products from Geislingen. The interior of the warehouse with its blue walls is impressive. There are pipes of various sizes stacked closely together, reaching a height of almost ten metres. A crane hovers under the hall roof, moving from one location to the next, lifting, lowering, storing and retrieving filled load carriers.

With its team of around 100 employees and extensive machinery, SÜLZLE Hagmeyer in Geislingen is the steel and metal distributor for, e.g., pipes, flat and round bar steel and profiles made of stainless and high-grade steel as well as aluminium and other non-ferrous metals. To protect finely ground and polished products from soiling and mechanical damage, the long-established company stores the semi-finished products in its stacking cradle system before shipping. The KASTO UNIBLOC A bar stock storage system was installed in the warehouse, which was built in 2001 for this purpose. Since then, it processes between 50 and 100 items per day. The steel and metal distributor stocks up to 2,000 tons of steel and aluminium in the approx. 98-metre long and 10-metre wide storage area.

Stacking cradle systems are characterised by their high-density storage capability. In this case, the UNIBLOC A offers more than 1,530 cassette spaces for three different stored goods lengths between four and six metres. A maximum of ten stacking cradles can be placed on top of each other. Up to three cradles can be moved simultaneously with the multiple transport crossbeam. The storage and retrieval process begins and ends at two stations. The KASTOlogic warehouse management software ensures the most efficient routing. This system assists employees in their daily tasks, visualises storage and inventories, and communicates with the HOST system from SÜLZLE Hagmeyer, ensuring optimum overall performance.

Ageing leaves its marks

After 21 years in operation, only a few spare parts were available, new or used, for the system's electrical and electronic components. This was true, especially for the crane that carries out the storage and retrieval. The effects of wear and ageing required constant creative and costly customised solutions. As a result, an extensive overhaul was necessary. The risk of a malfunction in the storage system was too great. "Longer unscheduled downtimes in the warehouse jeopardised the ability of the entire division to supply," explains Hans Gekeler, Director of IT at SÜLZLE Hagmeyer. SÜLZLE Hagmeyer enlisted the help of KASTO to improve the output reliability of the plant in Geislingen.

The storage, sawing and automation specialist from Achern shares the medium-sized steel distributor's approach to conserving resources. "The machine components and stacking cradles were still in excellent condition," reported Alfred Schwörer, Retrofit Team Leader at KASTO, during the status analysis. These components are not expected to malfunction in the next few years. However, the system's controls were severely outdated and could become a concern. The replacement of specific parts "would not have worked because they were not compatible with the remaining components in the control chain" Gekeler adds. Therefore, the experts from Swabia opted for a retrofit.

At the end of February 2022, KASTO updated the complete control electronics at stations and crane bridge. "We replaced the entire drive technology on the crane," Schwörer reports. This included switch components as well as motor and encoder cables. The existing measuring systems were replaced by an absolute encoder with integrated cable pull and an optical laser measuring system. In addition, the technicians updated the optical data light barrier and installed two climate control units in the control cabinets on the crane bridge. They also swapped out two frequency converters at the stations. The new components come with a service agreement to support the plant's internal maintenance department. "The retrofit not only eliminates the cause of many malfunctions, minimising the risk of downtime," Gekeler explains, comparing before and after. "At the same time, the new technology equips us for the future."

Even the experienced automation expert from Achern rarely undertakes retrofit projects on stacking cradle systems. The project also faced challenges due to the physical conditions. "Normally, we prefer to work with up to 15 employees on retrofit projects. This allows us to carry out several measures in tandem," explains Schwörer. "Unfortunately, that was not so straightforward in Hall 9." The crane bridge did not provide nearly enough work space for the amount of personnel required. The KASTO team overcame the challenging conditions and limited space under the hall roof by using three articulated aerial platforms and a truck-mounted crane to transport loads efficiently. The safety of technicians was given utmost importance due to the significant working height. Protecting them from falling or other incidents was the number one priority. "For obvious reasons, work safety preceded maximum speed," Schwörer strongly emphasizes.

Positive experience repeated time and time again

The retrofit at the beginning of the year was already the third project of this kind at SÜLZLE Hagmeyer. In 2011, KASTO upgraded a KASTO UNICOMPACT 4000 honeycomb storage system, which was put into operation in 1993. In 2010, retrofit measures on a sheet metal storage system from a third-party supplier lead the way. The positive experience from previous interactions influenced the decision to place the new contract. Gekeler praised its project partner by saying "KASTO always demonstrated exceptional project planning skills". "Goals are defined for each day and met consistently. The resources provided are selected to meet the current challenges faced taking into consideration the team size and the required auxiliary equipment." As a result, this project was also executed flawlessly as per schedule. "The fast and dependable execution of projects like this helps us to better coordinate with customers and suppliers.," reports the IT Director. KASTO completed the retrofit measures within three weeks and, most importantly, handed over a turnkey, reliable system in mid-March.