Heavy-duty systems like the EXS mobile racking system from SSI Schäfer are designed for load capacities of up to 600 tons. The overall height can be up to 16.5 meters, corresponding to the lifting height of the forklift systems used, thus minimizing the space requirement. This is particularly interesting for deep-freeze facilities, says David Eisenhut.
The expert in dynamic intralogistics solutions provides insights into how mobile racking systems integrate into warehouse processes, when automation is worthwhile, and how these systems help save energy costs. Excerpts from an interview with the expert.
Mr. Eisenhut, what are the practical advantages of such a mobile shelving system?
Since we only need a single work aisle, this results in space savings of up to 45 percent. Compared to static racking systems, this increases the warehouse capacity by more than 90 percent, allowing us to achieve maximum storage density. Additional benefits arise in terms of warehouse efficiency. For example, you can program the mobile racking system to achieve picking processes with minimal travel times. A key advantage is that the aisles between the carriages can be opened completely flexibly. This ensures that the transport systems used in the warehouse always have direct access to all storage locations and effectively avoid the relocations that are quite common in other high-density storage systems.
D. Eisenhut
Essentially, the goal is to minimize the system's footprint and achieve sufficient freedom in order picking. Customer projects demonstrate that there are four main areas of application where the benefits of a mobile racking system are particularly high. Temperature-controlled logistics is certainly paramount. If you operate a deep-freeze warehouse, you face operating costs that make optimal use of your storage space essential. The more goods that can be stored in the warehouse, the less energy is required to regulate the temperature-controlled volume. The resulting energy savings shorten the ROI of both the racking system and the refrigeration technology. Beyond that, capacity expansion is also beneficial for core business operations.
Logistics service providers should be particularly interested in this, right?
In addition to maximizing capacity, these suppliers are also focused on maximum handling flexibility. After all, the core competency of a 3PLer lies in precisely meeting the needs of diverse customers. The mobile racking system used must therefore offer sufficient options to accommodate the load carriers requested by the end customers. Furthermore, it is essential to keep picking times in mind to ensure that the agreed service levels are met.
All images: SSI Schäfer
You've already mentioned two key application areas: temperature-controlled logistics and 3PL. What are the other two?
Firstly, these are warehouse locations that can no longer be expanded, so it's necessary to consider how the existing space can be better utilized – customers in metropolitan areas, in particular, are facing this issue. Secondly, mobile racking systems are also suitable for companies in the manufacturing industry, where in many cases space-saving storage is more important than speed of handling.
What security services does SSI Schäfer offer?
The primary objective is to immediately detect any obstacles in the work aisles and act without delay. Our systems are equipped with a multi-stage warning system for this purpose: Access to the currently open aisle is controlled by light barriers mounted on the floor in front of and behind the mobile racking units. If a light beam is interrupted, the entire system stops. Additional light barriers are mounted on the long sides of the trolleys at foot level. This supplementary safety system detects in fractions of a second if goods – for whatever reason – fall into the work aisle while a trolley is in motion. In this case, too, the system stops immediately. Naturally, this also ensures compliance with all regulatory requirements, including those related to fire safety. Furthermore, we guarantee safe system operation in earthquake-prone regions. For this reason, we supply our products in an earthquake-resistant version.
In seismically active areas, preventive maintenance is certainly a key issue. But apart from that, such a system is already exposed to significant wear and tear risks. How does SSI Schäfer address this?
The question is absolutely valid. To protect the multi-ton mobile racking system, the supporting rail system, and the warehouse floor from wear and tear, we've considered a whole range of factors. Listing all the technical precautions here would go beyond the scope of our conversation. Nevertheless, let me highlight five key aspects. Let's start with load distribution. With a four-wheel chassis, we ensure that the structural load acting on the floor is distributed as evenly as possible. At the same time, we optimize the load on the wheels. Each wheel has a deep groove ball bearing with four raceways, which prevents uneven bearing loads. Furthermore, distance sensors ensure that the carriages are always positioned parallel to each other across their entire width – regardless of whether they are parked or in motion. The electric motors of the racking carriages, which have two gear stages with direct gearing, also ensure smooth movement. The rail profiles, in turn, are made of high-strength steel with a specific profile that allows for stable anchoring in the warehouse floor slab. All of this ensures that maintenance costs and downtime of the racking systems can be minimized.
How much can the system be automated?
On request, fully automated operation is possible, in which the system synchronizes with driverless transport systems (AGVs) and all processes are controlled purely digitally via a fully integrated warehouse management software.
(…) The goal is a 360-degree view of all internal goods and material flows. In this way, the automation potential of a mobile racking system can also be fully realized.
