The challenge that Wernsing faced as a producer of potato products was to fully utilize seasonal potato harvests, i.e. to process them in bulk and store them at a single location until they were sold. "The aim was to create maximum capacity on a very limited footprint," says Fabian Spitz, Sales Technologies & Systems at Westfalia, describing the objective. "Our multi-deep compact warehouses have a space utilization rate of around 95 percent and make optimum use of severely restricted floor space."

The production of frozen potato products and non-refrigerated foods is generally carried out in larger batches. "The satellite warehouses with enormous storage density and capacity in a minimal space are an ideal fit for our product range structure," confirms Alfred Kessen, Managing Director of Materials Management and Purchasing at Wernsing Feinkost. "Multi-deep storage is much more cost-effective for us than single bin storage."

Compared to the multi-deep storage concepts of other providers, Westfalia's response to the stressful conditions for loading aids was convincing. "Storing high weights over a long period of time - in this case units weighing around 1 tonne with potato products - puts enormous strain on pallets," says Fabian Spitz. "This causes them to bend in warehouses with double support, which can lead to malfunctions. With the combination of a triple support - an additional middle rail in the storage channels - and the chain satellite load handling attachment, we enable long service lives with high system availability." The satellites, which are split for the special storage profiles, "move under the pallet and pick it up very gently. The pallet does not change position. This also allows higher dynamics during storage and retrieval," emphasizes Fabian Spitz.

Westfalia was able to draw on a particularly wide range of different satellites for the transportation of individual or multiple load units, including unusual formats, instead of having to rely on a few standard shuttles. Spitz: "With this modular system, we can fine-tune our storage systems to any requirement."

Warehouse automation contributes to climate neutrality

Wernsing is the first company in the potato processing industry in Germany to be certified climate-neutral since October 2020. A process that was initiated back in 2002. The status is reviewed and optimized annually through site climate assessments with the certified consulting firm ClimatePartner. "We are constantly trying to reduce and avoid emissions. And offset them through climate protection projects from Climate Partner," says Alfred Kessen. With the high-bay warehouses, general contractor Westfalia provided a decisive building block for the sustainable growth of the food producer in several respects.

"We take a holistic approach to our investment decisions," says Alfred Kessen about the award of the contract. "We consider our investments economically, ecologically, socially and in terms of energy as part of our energy management system, for which we were certified in accordance with DIN EN ISO 50001 back in 2013. The storage system we chose also impressed us in combination with the energy-efficient storage and retrieval machines." These have intelligent drive controls for energy balancing between the travel and lifting axes - braking energy is made available as lifting energy, for example - and electricity is fed back into the system. The bearing layout also reduces energy consumption. This is because the multi-deep warehouses manage with only three storage aisles and vehicles in standby mode, and the high storage density reduces the space that needs to be cooled. Thanks to the high capacity at the site, logistics could be bundled in an economical and resource-saving manner.

"As part of our continuous growth, we have increasingly used external storage capacities. Large quantities of goods had to be returned to our central warehouse for logistical reasons," explains the Managing Director of Materials Management and Purchasing. "Wernsing already had over 60,000 storage spaces for stocking foodstuffs. With the expansion of around 23,000 storage spaces, automated with space- and energy-saving satellite technology, we can provide storage and shipping logistics with simplified processes and very effectively directly from the production site."

Economic and social sustainability

"The fact that the automated storage system makes warehouse processes more efficient and safer was also important from a social perspective," emphasizes Kessen. "With the automated warehouses, we are addressing the shortage of skilled workers and the challenging working conditions in the frozen food sector. We wanted to keep the number of staff required for storage and retrieval to a minimum and at the same time reduce the workload."

Another special feature of the Westfalia warehouses are the maintenance lifts on the storage and retrieval machines (SRMs). In the extreme cold and deep-freeze storage environments, which are also inerted for fire protection, the lifts take the strain off the staff. Fabian Spitz: "They enable the service staff to reach every point in the 29-metre-high warehouses with minimal effort."

Westfalia's project planners and engineers worked with Wernsing to find the ideal balance between compactness and access frequency. The access frequency is lower than with single bin storage systems, but is ideal for single-variety channels and longer storage times. The two 56.5 meter long, 29 meter high and 62.2 meter and 41.6 meter wide deep-freeze warehouses offer a total of 17,360 spaces for Euro pallets for load units weighing up to 1,050 kg. The 61 meter long, 9.2 meter wide and 29 meter high refrigerated warehouse has 2,988 storage locations for load units weighing up to one ton, measured in terms of industrial pallets. Depending on the formats, there is space for up to 23,066 units in total. "In each warehouse, we use a storage and retrieval machine with a chain satellite for crosswise storage," says Carsten Lüdeking, the responsible project manager at Westfalia. "Together, the three storage and retrieval machines achieve up to 184 pallet movements per hour."

Another special feature is the enormous flexibility of the warehouse layout. "The two deep-freeze warehouses were built at an angle of 20° to the refrigerated warehouse in order to take the site boundary into account." The available space was optimally utilized with graduated channel depths. The deepest storage channel provides 24 storage locations.

Seamlessly integrated into the existing building

The stacker cranes manufactured in-house were supplied including PLC. The storage system was integrated into an existing automated material flow system from a market competitor. Lüdeking explains: "Westfalia integrated the walls, shelves and roof of the new system in a self-supporting silo design and connected the system to existing logistics software on the software side."

The electric overhead conveyor of the inventory system, which transports the units from production to the warehouses - or from there to dispatch - is connected to each of the three storage aisles via pairs of L-shaped storage and retrieval lines of the Westfalia system. After a contour check, the pallets on the conveyors each pass through an airlock with vertical gates. These airlocks shield the oxygen-reduced warehouses for fire protection. The conveyors transport the pallets to a turntable, which turns them to the aisle for transfer to the SRMs. The retrieval lines are set up accordingly.

Westfalia implemented the project from December 2020, the new warehouses went into operation in June 2022 and were filled with products from the current potato harvest by the end of October. The products will be stored there until they are fully sold.

This article appeared in issue 7/23