Loading docks are critical links in America’s supply chains, helping bring products from factories and fields to end consumers. They are usually one of the busiest areas in any industrial facility. Buzzing with forklift activity, workers talking on radios and vision-obstructing stacks of pallets, opportunities for accidents are everywhere. It is no surprise, then, that shipping and receiving operations account for almost 25% of all industrial injuries.
The ever-growing level of consumer expectations has increased these hazards by causing material handling personnel to move at a faster pace to keep up. Overnight shipping, for example, was once considered a luxury by online shoppers but now is an expectation. Marquette University supply chain expert Doug Fisher points out this shift, noting, “Amazon’s goal is not to deliver in one to two days—it’s goal is to de liver in one to two hours.”
To mitigate risks and ensure safety, it is important that facility managers conduct regular safety training, keep an open dialogue with logistics employees and follow a stringent set of safety protocols. Installing intuitive, advanced equipment that helps support these protocols and clearly communicates potential danger is another key. Loading dock controls are a prime example.
A Safe Sequence of Operation
At one time, each piece of loading dock equipment—such as vehicle restraints, levelers and overhead doors—was manually operated. Life got easier and safer for dock workers when technology advanced to the point that these operations became automated. No more need for lifting levelers or overhead doors! And the trend continues.
Now, loading dock control systems can interlock these operations and automate the loading and unloading process with just the touch of a button, starting with the vehicle restraint. Automatic vehicle restraints help eliminate the risk of placing “boots on the ground” on the dangerous drive approach and physically chocking and un-chocking truck tires. They also eliminate the opportunity for driver mistakes by clearly communicating with red and green lights when a trailer is restrained, helping ensure the trailer doesn’t mistakenly pull away when a forklift is still inside.
However, there still exists a danger that workers can operate these pieces of equipment incorrectly or in the wrong order. If a leveler or door is lowered too early, a backing trailer can damage it. If a restraint is unlocked before the leveler is stored and a forklift enters or exits the trailer, the chance of a catastrophic early departure accident increases exponentially.
Loading dock controls can now be programmed to operate only in a safe sequence of operation, with individual elements of the system interlocked. For instance, some dock control systems can be programmed with a green light interlock, which disables the use of the push button dock leveler or overhead door until the vehicle restraint is safely engaged; an overhead door interlock, which requires overhead doors to be opened prior to leveler operation; or a stored leveler interlock, which ensures that the leveler is stored safely before the restraint can release the trailer. If a worker presses the control box button for an individual system element in the wrong sequence, it won’t work—ensuring that no safety procedures will be skipped.
"To mitigate risks and ensure safety, it is important that facility managers conduct regular safety training, keep an open dialogue with logistics employees and follow a stringent set of safety protocols."
Additionally, some automatic restraints can be integrated into building management or security systems, providing another level of security and protection against external tampering. Restraint monitoring has taken a step forward as well. Lock verification systems, which use an outside camera and inside monitor, can show when a trailer has arrived at a given dock position and when/if it is properly restrained. Dual camera systems can also help detect if a trailer stand is present.
While these systems were originally built to work with rotating hook-type vehicle restraints, facilities using wheel chock restraints can now benefit from constant communication safety. High-tech chocks have become available which use an ultra-sonic sensor to indicate lock/tire engagement to the system. If the sensor loses tire contact, audible and visual alarms alert dock personnel inside and outside the building that the chock needs to be re-engaged prior to safely continuing operations.
Light Communication Inside the Loading Dock
Light communication systems are another example of using technology to improve safety at the loading dock. For decades, most loading docks have used traffic-style red/green signaling systems inside and out to indicate if a trailer has been secured and is safe to enter (red light outside and green light inside), or is unsecured and could pull away (green outside and red inside).
The last 10 years have seen upgrades to this basic communication tool. For example, highly visible LED lights in the corners of dock doors are available to clearly communicate to forklift operators who might not be able to see the red/green light at the control box due to stacked pallets or other equipment. For forklift operators inside the trailer, LED lights inside the leveler provide visual confirmation that the trailer is still secured to the loading dock.
“If visual and sound communications are ignored or ineffective, a physical barrier provides the ultimate safety for workers at the loading dock.”
The most recent developments in dock safety involve motion sensor-based systems. One such system projects a blue light (similar to forklift safety lights) onto the leveler when activity is detected inside a trailer, alerting workers that a forklift could back out at any moment. This type of system can be integrated with advanced control boxes to keep the vehicle restraint locked until the activity stops, ensuring the trailer doesn’t pull away with a forklift operator still inside.
Protecting Workers Outside the Dock
Motion sensor-based light communication can also mitigate the danger of backing machinery (specifically semitrailers) outside the loading dock. This is critically important considering that OSHA cites backing equipment and caught-between injuries as two of the four leading causes of workplace fatalities. In fact, according to OSHA, there have been 40 fatal accidents involving backing tractor trailers in a six-year span.
The leading vehicle restraints have the ability to incorporate an external motion sensor, which triggers an audible and visual alarm to alert workers outside on the drive approach when a trailer begins backing in. These types of multisensory warnings immediately gain the attention of workers who might be in harm’s way.
Loading Dock Safety Barriers
If visual and sound communications are ignored or ineffective, a physical barrier provides the ultimate safety for workers at the loading dock. The dock presents various opportunities for dangerous falls. In fact, falls off of a loading dock can take place even if the dock’s doors are closed, since most dock doors are not designed to stop a forklift.
The most advanced loading dock safety barriers are made from PVC-coated fiberglass mesh and heavy-duty polyester; look for models that are 58 inches tall and meet OSHA’s Walking-Working Surfaces regulations. They should be rated for impact based on the typical speed and weight of the forklifts accessing that dock opening. The leading loading barriers can stop up to 30,000 pounds, stretch across openings larger than 16 feet, and can also be integrated into the safe sequence of operation on dock controls. Once the trailer is securely in place and the lock button is pressed, the restraint engages, turning the light on the control box green and releasing the barrier for easy access to the trailer.
Manufacturing and industrial operations that have pits or recessed areas should be protected with barriers as well. These operations require access in most instances, so removable options should be considered when specifying the right barrier.
While facility managers have traditionally chosen barriers based on relatively simple criteria (e.g., the ability to stop a 10,000-pound load at 4 mph), a new formula is quickly gaining popularity. Called the Barrier Load And Speed Test (BLAST), it takes into account the typical mass and speed of loads moving around the hazard. BLAST is centered on the formula for kinetic energy (EK = ½mv2, where m=mass [weight] and v=velocity), which takes into account both the weight and speed of the impacting object.
Loading Dock and Trailer Management Software
Interlocked, programmable dock controls were a huge step forward, and the newest advancements involve loading dock software that provides real-time status information. These systems can track almost all activities in the logistics process. From the moment drivers arrive at a facility and check in at an optional touchscreen kiosk, managers and yard personnel have a constant, real-time digital view of where the trailer is in the loading/unloading process.
This type of software takes the place of internal paperwork and distracting radio conversations that can all too often lead to human error. Bringing order to what can be a chaotic process not only improves safety and increases productivity, it can help reduce detention and demurrage charges incurred when trucks have excessive wait times before loading or unloading.
A Systemic Approach to Loading Dock Safety
The loading dock can be a busy place with many distractions. Unfortunately, one mistake can lead to lost product, damaged equipment or serious injury. To address these challenges, facility managers should look beyond individual pieces of equipment and take a more systemic approach. Using advanced loading dock software and controls that incorporate a safe sequence of operation, motion sensor-based LED light systems, restraint monitoring, audible alarms and barriers puts any facility manager on the right path to minimizing risk, increasing worker safety and ultimately making the plant’s operations more efficient.
Walt Swietlik is director of customer relations and sales support for Rite-Hite, a manufacturer of loading dock equipment.