Discovering the Ideal Storage Solution for Long Loads and Materials

Long Objects in Warehouses and Factories

The predominant demand for automated storage & retrieval systems (AS/RSs) primarily centers around industrial standard pallets, including Euro pallets, JIS pallets, GB pallets, US pallets and other national standard variants, typically falling within the range of 1,200 x 1,200 mm. From time to time, we engage with customers seeking solutions for load sizes significantly beyond this range, from 2 m to over 6 m. What do they typically handle?

The primary requests often originate from wholesalers of metal bars and pipes, closely followed by diverse manufacturing companies dealing with either lengthy raw materials or work-in-process items. Within this domain, the stored items encompass a wide range, including pipes, metal bars, construction materials, window sashes, lumber, aircraft parts, train components, furniture, automotive bodies, and more.

Metal bars

Water pipes

Window sashes

Lumber

Aircraft parts

Automotive bodies

Train components

Furniture

How are Long Objects Handled in an Automated System?

If automation is not applied, we find that long items are typically stored on the floor, stacked on top of each other. But that approach raises the following problems and difficulties:

• Occupies significant floor space.
• Impacts the smooth supply of the right items just in time for production or shipping.
• Hinders work place safety due to the potential for load collapse.
• Hampers inventory management accuracy.

At Daifuku, we have been addressing these market needs since our first AS/RS project for 6.2-meter steel bars back in 1986, and since then we have developed two major automated storage solutions.

Shuttle Fork AS/RS

The most popular storage solution is to pick up the load with two shuttle forks from the bottom. This is particularly suitable for manufacturing companies that want to utilize the limited space alongside the factory wall. For instance, when utilizing an AS/RS system to store steel pallets measuring 6.2 x1.0 m, it typically requires a width of approximately 3.6 m. The input and output to the AS/RS can be done from a crane aisle end or from a rack side, depending on operational needs.

The infeed/outfeed conveyors and cutting machines are located on the sides of the racks. This configuration ensures smooth retrieval, picking, and feeding to the cutting machines.

Input/output conveyors are placed at the end of the automated warehouse. Installation width can be minimized.

AS/RS with Honeycomb Rack and Push-Pull Stacker Crane

In 2015, Daifuku supplied Sakuma Special Steel with a honeycomb-type AS/RS for 6.2-meter steel bars. The system consists of two stacker cranes equipped with push-pull extractors and deep honeycomb-type racks holding over 2,500 pallet locations, enabling high-density storage of substantial volumes in one place. This system is unique in that the loads are stored in a 90° rotated orientation, compared to the shuttle fork handling.

While the system offers superior storage density compared to the fork extractor solution, it comes with a drawback of longer storage or retrieval cycles as the crane has to push and pull the 6.2-meter load to and from the rack. Daifuku overcame this issue by adopting a dual crane solution, a system in which two stacker cranes work simultaneously within the same aisle.

Although the storage density of the push-pull extractor system appears attractive, it is not a universal solution for every business. Since this storage approach requires a space of around 19 m in width, it may not be ideal for those seeking medium-volume storage within a limited factory or warehouse space. For this reason, it is generally recommended for businesses dealing with large volumes in a dedicated warehouse setting, such as metal material distributors and wholesalers.

How to Choose the Best Solutions for Your Long Items

Managing odd-shaped items typically demands additional caution and time compared to handling industrial standard pallets. If you're aiming to improve efficiency and safety of handling long items, consider evaluating the volume you need to store on-site, the frequency of retrieval, and the available space. The resulting considerations will guide you toward either opting for a shuttle fork or a honeycomb solution. Uncertain about where to begin? Feel free to contact our global sales teams for consultation.