By Aaron Conway, Contributor
Protective guarding is essential in material handling facilities. Guardrail, safety gates, mesh cages and bollards are just a few of the safety measures that should be implemented in every facility for employees working at heights, around machinery and at the loading docks.
However, when you purchase protective guarding of any type, it’s important to understand that it is often not a “one-type fits all” kind of purchase. The key to selecting the right protective guarding is knowing what the application environment is like and communicating that with the equipment provider. Review the environment and processes with operations, maintenance and safety teams to determine the specific requirements for each application—so those features are designed into the safety system.
Three aspects of the application environment are crucial in selecting the best protective guarding solution for your facility: climate, location and traffic. Understanding these three factors will make sure your safety system is the right design for the facility.
In a basic material handling or DC environment where there is a normal climate, palletized material can be lifted to an upper level and picked or moved with a pallet jack or conveyors. In such a situation, the use of painted, mild steel protective guarding is often the right choice. This is an economical and durable solution. Most protective guarding manufactures use a powder-coating process instead of wet paint for a more durable finish that will not flake or crack.
Many facilities have sanitation requirements that do not allow any type of paint, whether powder-coated or wet. Some of these areas might be able to use mild steel equipment with specialty finishes, such as Steel-It Paint, which includes FDA-approved, stainless steel pigments.
Facilities may feature applications in which goods are stored and picked in extreme hot or cold climates; other facilities feature areas where equipment and material is routinely sanitized, washed down and cleaned. In both of these instances, stainless steel is the best choice, as it can withstand extreme temperatures and allows material to be washed down and cleaned without concern of flaking or chipping paint contaminating the facility or material. Galvanized steel or aluminum gates may be required if the application uses caustic material.
For example, when this company’s safety gates are constructed in stainless steel, the entire design is fabricated out of 300 series stainless steel with all stainless hardware. All open ends are capped to prevent water and debris from entering the system. When required, we can use continuous welds and eliminate any bolts holes in the tubing. And, before shipping the unit to the facility, we tig-brush, bead-blast or electro-polish the entire unit to remove any burn marks from the welding process in order to ensure installing the cleanest system available.
Climate also impacts the power options that may be involved with the protective guarding you choose—it’s often selected in conjunction with safety gates. Ensure the motor used is able to operate within any extreme climate conditions that might be present in the facility. Motors are available in water- and explosion-proof options. Numerous controls, such as flashing lights and caution alarms, can be added, as well.
Traffic patterns near the location of the protective guarding must be considered before the purchase of protective guarding; that goes for both outdoor and indoor applications.
Loading dock environments are different for every facility; they all have their specific traffic patterns and can feature multiple applications, often happening at the same time. All protective guarding must accommodate the flow of traffic—often including trucks, lifts and employees—moving throughout the area. It’s important to consider any other aspects that could disrupt flow, such as awnings and doors.
Once you have all of the traffic patterns in detail, the protective guarding can be configured based on the operation of each application or area. For example, one grocery customer needed to accommodate the flow of trucks and patterns for each dock, when considering safety gates for its lifts in the loading dock. Some of these areas used gates that swing outward; sometimes with a single gate that covered the entire 8ft lift. In other applications, bi-parting gates were used to prevent the gate from swinging into the delivery area. Our team also created a safety gate that can move into position after the traffic has moved, and then can be rolled into a safe position once the material has been transferred.
Inside the facility, forklift trucks and AGVs are often moving around the facility, loading and unloading material from pallets. Cobots or robotic machinery may also be present. It’s important to understand the patterns and movements of each of these aspects before purchasing protective guarding to ensure not only it will protect your employees—but also keep your production intact.
Technology is often needed to allow the protective guarding to communicate with other plant equipment and software. For example, radio frequency sensors integrated with power operation on some safety gates send lift trucks and AGVs a signal when the ledge gate is up, telling it to load material to the pallet drop area. After the pallets are loaded, the sensors from the vehicle send a signal to the safety gate to use the motor to close the ledge-side gate, so employees can work with the material. Photo eyes can also detect the presence of a person or object, and prevent the safety gate from opening or closing.
When it comes to protective guarding solutions, environment greatly impacts the type and design. Review the physical location in the facility and work with employees to understand the process and the inherent dangers in each application. In addition, consider the total space available; the amount of clearance needed for employees to work; any machinery or other interference that could impact movement or safety; the materials being worked with; and the climate in which it will be located.
Because each environment is different, we’ll use a few examples of locations in which safety gates are commonly found to illustrate the impact it has on the guarding design.
In locations with cold climates or frequent sanitation, safety gate solutions should have as few moving parts as possible, such as a pivot design safety gate. This design uses a pivoting framework that utilizes fewer moving parts to provide a safe environment for employees working around the pallet. The rear gate pivots back, beyond the upright to secure the pallet, then moves out of the way when the ledge gate is closed. With this design, make sure the moving gates will not interfere with the truck aisle, and that there is adequate clearance behind the pallet drop area. Note that the space required for this operation may be an issue, if a takeaway conveyor is located right behind the pallet drop area.
If depth on the platform is limited due a narrow aisle, the best safety gate design may be a tri-sided safety gate. This safety system uses a gate that moves straight up and down at the ledge—never extending into the lift truck aisle, and a rear “u”-shaped gate that closes to capture the pallet, then moves up and out of the way, to provide egress behind the area.
In pick modules, a rack-supported safety gate is often the best choice for fall protection in most of these configurations, as the gates attach to existing rack uprights and don’t require the systems to be billed into decking. Due to the configuration, these safety gate models never extend into the truck or picking aisle and do not interfere with the truck loading the upper levels of multi-level picking systems. The gates open and close within the confines of the pallet drop area, so the gate at the ledge opens and closes flush with the ledge, and the rear gate is flush with the rear uprights of the system.
If the picking bays include pallet flow lanes in which multiple pallets deep are loaded, then you should install a gate that is designed as deep as the flow lane. The additional depth ensures there is a gate in place at all times and prevents an employee from entering the aisle while the area is being loaded. This is especially important in a cluster-picking design, where employees travel an aisle between the lanes to pick from multiple pallets at the same time.
No matter what type of protective guarding you seek for your material handling operation, make sure you take all aspects of the environment into account. If you review the climate, traffic and location, you’re on your way to selecting the best design for your guarding solution. WMHS
About the Author
Aaron Conway is President of Mezzanine Safeti-Gates, Inc., a provider of pallet drop safety gates for material handling. (www.MezzGate.com)