One of the questions we get asked a lot is whether or not to power operate a pallet drop gate. For most applications, we recommend skipping the power option. Manual operation creates the highest level of safety because the operator on the platform, who we are trying to protect, is the only person controlling the opening and closing of the gate. This can be very important for any material handling or manufacturing application.
The majority of the end users inquiring about power operation believe that operations will be slowed unless the fork lift operator can open the safety gate. The concern is that the lift truck operator will go to load a pallet and the gate will be closed. This would cause the operator to get off the truck, climb up the stairs to the mezzanine level, open the gate go back down below to the lift truck to finish loading the pallet.
We agree that this is an issue when using a single-gate system like a sliding gate or a swinging gate. For that type of design, in order ensure safety in the area the gate has to be closed; and in order to load a pallet the gate has to be open.
However, this is not the case when using a dual-gate system, which is the type of guarding that all pallet drop areas on elevated work platforms should use according to ANSI MH-28.3. When using a dual-gate system, the area can always be safe because the employees working in the pallet drop area can close the rear/operator gate when they are done removing the material to ensure the area is always ready to receive a pallet because the ledge-side gate opens when the rear-side gate closes. As long as the gate is left in this position the area is always ready to receive a pallet so there is no reason to give control to lift truck operators down below.
How to make sure employees close the rear-side gate is a concern of customers who understand the issue with power-operation from below. We have found over the years that this issue gets resolved by communication and training among the operators. More often than not, the position of the gate becomes a signal so when the picking on the mezzanine is ready for the area to be replenished, he/she will toggle the gate, closing the rear-side gate, which opens the ledge side gate. Now the lift truck operator looks up and sees the ledge-side gate open and knows it is time for the area to be replenished.
Sometimes we get asked to power operate the gate because the operator on the lift truck is the same operator that goes up on the elevated work platform. But, this scenario is ideal for manual operation because the operator must leave the ledge-side gate open when they go down to the lower level, because if they do not, they will have to go back up to the mezzanine to reverse the position of the dual-gate system. After making that mistake once, they’ll likely remember to always leave the ledge-side gate open for the next time they’ll be loading.
Of course every application is different, and everyone’s operation is different, which is why we do offer the option to purchase our safety gates with power operation. All of those power-operated systems include built-in safety features like photo eyes that detect the presence of a person or object and prevent the gates from closing, along with a clutch that will engage if the gate were to make contact with an object, which is adjustable so it can be set to the proper sensitivity for that specific environment. We also add power to gates that are involved in operations with AGVs.
The motors are all commercial operators will built-in safety features and numerous controls that can be used, like radio frequency remotes on the lift truck, and flashing lights and caution alarms. But we recommend caution on all of these remote operators, and always advise customers to test the unit in manual operation because they can always add the power option later, which by the way, we’ve never had a customer take that advice and then come back later to add power operation – they always stick with the manual operation. With proper training and education, the manual operation will create the safest environment, and shouldn’t slow down the operation.