The manufacturing and material handling industries are abuzz about the robot revolution. Automatic guided vehicles’ (AGVs) role in the supply chain and material handling has been increasing, and they are increasingly working side by side with humans in facilities like warehouses and distribution centers.
These vehicles, like driverless lift and forktrucks to material moving robots, get integrated into the facility infrastructure and operational processes. AGVs use technology to move throughout the facility - most often using Proximity Laser Scanners and Laser Scanner Interface technologies. These technologies help the AGVs determine objects and locations in the facility, as well as integrate with other facility machinery and equipment.
AGVs are programmed to follow a guidepath - in distribution centers and warehouses, they often move pallets and containers of material from one place to another. With no driver, the machines are being told where to load and unload the materials being moved, often through the use of PLS technology.
The rise of AGVs is allowing material handling systems to grow in size; today’s facilities are much bigger and taller. Warehouses and distribution centers today employ both persons and machines to get the work done more efficiently.
ANSI B56.5 outlines safety standards for the use of AGVs in an industrial facility, but it primarily looks at the space required for the vehicles, load stability, sound requirements and emergency controls for stopping the vehicle. Because the vehicles are driverless, the standards do not look at safety of the workers interacting with vehicles outside of emergency stops and sensors to keep from running into people at ground level.
Even with the AGVs, there is a need to keep the persons working with and around the AGVs safe. It’s still very important to guard areas that material is being passed into...there are also fall protection regulations from OSHA and ANSI that mandate workers are kept safe in these pallet drop areas - especially upper levels of over 48 inches. Dual-gate systems like our line of pallet drop safety gates are needed to keep workers safe.
Many material handling operations place people in the elevated workstation in which the AGVs are loading and unloading material in pallet drop areas that are two or three stories tall. This scenario is very common and requires fall protection for workers that are working the pallet in these drop areas.
We have worked with many companies that use AGVs in their facilities to integrate the important safety systems into their workflow. To be most efficient and keep operations proficient, is important that the AGV can interact with the pallet drop safety gates. Because they are unmanned, the AGVs need a way to understand if the pallet area is available for unloading and loading material without relying on an employee to perform any extra steps.
Next week we'll outline a job that we did with our Roly safety gate for an operation that uses AGVs.
Most distribution centers utilize rack modules in their operations in order to maximize storage space and operational efficiency. Rack modules can be designed in a wide variety of configurations depending on the applications. Often these configurations require space for workers to pick from the pallet drop areas throughout the rack structure, or to stack empty pallets and empty totes into open bays.
When workers are involved in operations on elevated work platforms and pick modules, it’s necessary to plan for safety and fall protection. There are a number of ways safety can be achieved, and industry standards like those issued by ANSI and OSHA require a dual-gate system. Safety advantages provided by dual-gate systems, like the models we offer, ensure that workers are safe at all times; when the ledge gate is open, the rear-side gate is closed, preventing the worker from access to the ledge. When the rear-side gate is open, the ledge-side gate closes, providing a safe, enclosed workstation while the bay is picked.
A dual-gate system also keeps the picker a safe distance from the lift truck loading a pallet, as a fixed barrier will be in place while the pallet is being pushed into the bay. This creates a physical barrier between the picker and a pallet being pushed into the area with the force of a lift truck.
A dual-gate safety system is now a standard in the industry, so the decision to install them to secure picking positions and empty pallet return bays is obvious. But the real decision is what type of dual-gate system. There are dual-gate pivot and Roly models, both of which will maintain a safe environment at all times; there are also rack-supported and free-standing gates.
A Pivot Gate has few moving parts and is often the most economical choice, but keep in mind that this design needs room for the gates to pivot, or arc, when operated. When the pivot gate is in use, the ledge-side gate extends out into the truck aisle, and the rear-side gate extends back into the picking aisle. This often is not an issue, but can be if the picking aisle is narrow, or if the lift truck is loading multiple levels.
A Roly Gate solves this issue as the design uses gates that open and close flush within the confines of the rack structure, so the ledge-side gate opens flush with the ledge, and the rear-side gate opens flush with the rear-side column.
Both of these designs are available in both free-standing and rack-supported configurations. When operations needs flexibility, and pallet drop areas frequently move locations within the facility, a freestanding safety gate model can be used efficiently within a rack module. The free-standing gate can be unbolted from the decking, moved to another location, then re-secured. We have seen this work well for some unique material handling operations, and with companies that require a flexible layout.
The other option is Rack-Supported safety gates. This style attaches directly to the existing rack uprights instead of being lagged down into the decking. The rack-supported model has three main advantages over a freestanding model: (1) space savings, (2) more secure connections and (3) cost savings. By utilizing the existing pallet racks for support, the rack-supported model takes up a minimum amount of space in the rack bay, gets tied into the entire rack system and uses few components.
You’ll also have to decide on the size of the safety gate. Because we’re talking about integrating with a rack-module, the existing bay size determines the width of the gate, but you’ll need to decide on the depth and the height that is required. The safety gate needs to be deep enough to accommodate the pallet without being so deep that it projects too far into the picking aisle. With a standard 48” deep pallet, the safety gate should provide a minimum of 56” in clearance to provide room to load the pallet into the area. Because most uprights are only 48” deep, often the safety gate will extend beyond the upright, either back into the picking aisle or into the lift-truck aisle with a platform extension. The safety gate should be made tall enough to accommodate the tallest pallet with some room factored in for fork truck lift-off space, and to allow pickers room to enter the bay to work the pallet, without being too tall that the raised gate is difficult to reach. Sometimes a beam may need to be removed to provide adequate height.
Many dual-gate systems that are both free-standing and rack-supported can be power operated with remote radio frequency controls. To learn more about whether or not to power operate a pallet drop gate, please see this blog post on the subject.
The decision to secure picking positions in a multi-level rack picking module should be an easy one. Where it gets complicated is deciding on which safety gate will best fit your application and how it should be sized and configured. This is where a professional in the industry should be consulted, either through a material handling consultant, distributor, or by reaching out to us.