STOPA LG-E shelving system for long-span goods: designed with the future in mind

The STOPA LG-E long goods storage system stands for a high degree of space utilization, greater productivity and fast access to the material

In this case, the STOPA LG-E long goods storage system developed by STOPA Anlagenbau GmbH, Achern-Gamshurst, is around seven meters high, eight meters long and four meters wide as a double tower (without station). The investment in the system is proving to be trend-setting because Lehnhoff Hartstahl benefits from modular components that allow the operator to adapt production processes to increasing or changing market expectations. In this case, the LG-E long goods storage system has 39 storage locations for cassettes 840 millimetres wide, 6,500 millimetres long and 215 or 250 millimetres high. The load carriers are designed for a payload of up to 3,000 kilograms and are equipped with compartments so that the contents can be managed separately. As the stored goods are completely contained in the cassette, the result is denser storage.

Other advantages include less material damage and easier handling. In the function of the long goods warehouse as a link between the stocked material and the processing machines to be supplied, the system enables rapid storage and stocktaking during deliveries, supported by software. The use of cassettes is more efficient than area storage, especially as it results in shorter access times to the material and a better inventory overview based on integrated material management. The warehouse can also be used flexibly with different storage and retrieval stations. Lehnhoff Hartstahl, market leader in its sector, specializes in quick-change systems and attachments for excavators of all brands and types up to weights of 130 tons. The company, which has around 200 employees and an annual turnover of 40 million euros, stores round and flat material, some of which is made of high-strength blade steel, in lengths of three and six meters up to the hall ceiling. No interfaces to the sawing machines have been installed. The material is transported using an indoor crane with suitable lifting gear. “Since we have been cutting the knife steel in particular as long material at the saws in packs since the installation of the storage system, this results in further time savings,” explains Spengler. “We limit returns to exceptional cases because we process the bars as completely as possible to avoid leftover pieces, which we can also manage.”

STOPA can set up the long goods warehouse inside the hall directly against an external wall and allow a transport cart to drive directly into the open through a roller shutter door.

At station 1 of the long goods warehouse, the operator, who supplies civil engineering companies, dealers and OEMs, uses a transport trolley at a fixed height with a lifting device for storage and retrieval. STOPA safeguards all functions by means of dead man’s operation and checks with the aid of a light barrier. During storage, the SRM picks up the cassette and transfers it to the transport trolley, which parks in the waiting position below the rack block. The operator receives this information at the control panel, whereupon he opens the roller shutter to exit the trolley and closes it again as soon as the trolley is in its final position. After loading, the process is reversed. The opening and closing of the outer gate is integrated automatically with appropriate monitoring.

The height positioning of the stacker crane is carried out by an absolute, load-independent digital distance measuring system, which eliminates the need to move to a reference point. All functions are reliably monitored. To avoid excessive loads during storage or retrieval.

Station 2 of the long goods storage system is equipped with a transverse cassette conveyor mounted on the long side for storage and retrieval. The safety requirements correspond to those of station 1, supplemented by protective fence elements against falling parts on the steel structure and access monitoring.

A programmed Siemens hard PLC controls the system. An integrated control panel with touchscreen is installed in the control cabinet at an ergonomic height, which is responsible for operating the system and displaying the system statuses. It would be possible to automatically process individual orders after entering the start and finish coordinates.

The long goods warehouse is equipped with the STOPA warehouse management software LVS-Turm, which has all the functions required to operate a high-bay warehouse as a fixed location warehouse. The data is managed by a Microsoft SQL Server Express database. A teleservice is available as part of the warranty, which includes diagnostics and recommendations for rectifying faults. It includes remote diagnosis of the system control via the STOPA Tele-Presence portal. Thanks to the WMS, the LG-E long goods warehouse, which went into operation at Lehnhoff Hartstahl in August 2020, offers a wide range of functions that can be adapted to the desired requirements. “Not yet installed, but planned and prepared, is the data flow between the long goods warehouse and our ERP system as well as the systems to be supplied,” emphasizes Spengler. “This means that inventory data can be exchanged and transport orders can be placed that contain optional accompanying information for material tracking. In this respect, we benefit from seamless documentation of the stored goods.” As the software generates the orders automatically, some of the manual entries are no longer necessary. This is an advantage in terms of the reliability of the inventories, which are managed as total and partial inventories. STOPA has also integrated plausible, intuitive user guidance into the graphical program interface and hidden parts of the program that are not required. The access rights of individual users can also be restricted to defined areas of merchandise management.

The operation of the long goods warehouse, which offers almost 100 percent availability and works in two shifts, proves to be user-friendly thanks to clear graphical user interfaces. Regardless of whether full or partial withdrawals and additions or transfers are involved.

Frank Spengler, Production Manager at Lehnhoff Hartstahl, is absolutely satisfied with the chosen solution

Spengler sums up. “We are very satisfied with the chosen solution, which is based on a long-term partnership and local proximity. After a STOPA sheet metal warehouse, we have now invested in our first long goods warehouse from this manufacturer. We expect the payback period to be two years.” Compared to many market players and their entry-level products for automated material storage, STOPA has equipped the LG-E long goods storage system with significantly higher speeds. This advantage and the comparatively high station variance form the basis for a large number of storage and retrieval operations. In addition, STOPA has deliberately placed itself in the upper range of market players when dimensioning the components in order to ensure that the long goods storage systems have a long service life, even with intensive use.

Author: Jürgen Warmbol