The Next Generation of Dock Safety Equipment
Employers must continue to focus on forklift safety training and consider the use of multiple safety devices, such as strategically placed signs, painted aisles, and guarded walkways.
- By Walt Swietlik
- Sep 01, 2013
Despite widespread improvements in industrial safety procedures and training, the process of loading and unloading semi-trailers remains inherently dangerous. The hectic pace of materials handling environments, combined with vision and communication issues, can spell danger for inattentive forklift operators, dock attendants, service technicians, or bystanders. The growing use of global shipping container (intermodal) chassis and other trailer configuration issues also present dock safety challenges.
Each year in the United States, 20,000 workers are seriously injured and 100 are killed in forklift-related incidents -- almost one every three days. According to NIOSH, the most common of these include lift overturns; workers on foot struck by forklifts; persons crushed by forklifts; and falls from forklifts. This may be why forklift mishaps account for a disproportionate amount of the physical injuries in factory accidents; while forklifts are involved in only 1 percent of these accidents, they account for 10 percent of the physical injuries.
Forklift accidents aren't just a safety issue, though. They are also financially damaging. Forklift accidents cost employers millions of dollars every year in worker's compensation claims and lawsuits. One automotive industry study found that the total average lost time per forklift incident was 61 days -- nearly nine times that of any other accident.
Forklift Safety Challenges: Inside the Dock
Although forklifts are used throughout warehouse and production facilities, the shipping/receiving/staging area of a loading dock is one of their most common zones of operation. It is also one of the most dangerous. The loading and unloading of semi-trailers requires skill and close concentration from forklift drivers. They must maneuver in tight confines, and often under tight deadlines, while dealing with a variety of other challenges that can make it difficult to maintain awareness of pedestrians and bystanders.
Vision can be severely hindered inside a trailer, where forklift drivers are essentially operating inside a tunnel. This creates a dangerous blind spot until the forklift has fully backed out of the trailer. Likewise, the inability to see a forklift inside a trailer is concerning to other forklift operators. This problem becomes exacerbated when a trailer is approached from the side and a forklift is operating at the front end of the trailer.
For forklift operators, unloading and loading trailers is a balancing act. Though safety regulations and protocols encourage forklift drivers to operate with caution, production goals push them to work as quickly as possible. It is the operator's responsibility to make the right decisions, which is why operator training is mandatory.
Even the best-trained forklift operators must deal with certain realities of dock operation. These challenges include:
- Unexpected dock entry: Pedestrians and visitors often can enter the loading dock without warning.
- Stepping out of bounds: Pedestrians and visitors often step out of zones designated for pedestrian use, including: 1) Truck drivers who are required to enter a facility to engage and disengage the vehicle restraint; 2) Technicians who service docks; 30 Employees who manually assemble pallet loads; and 4) Employees traveling from dock opening to dock opening
- Open staging areas: The staging area in front of the dock door allows unrestricted movement of forklifts. Painted yellow lines on the floor offer little protection for keeping pedestrians and other forklifts out.
- Conditioning to forklift alarms: Operators and pedestrians can become accustomed to and ignore audible and flashing/rotating/strobe lights on forklifts.
- Difficulty hearing: Hearing protection can impede a pedestrian’s ability to hear audible devices or sense where the sound is coming from.
- Forklift operator preference: Forklift operators typically rely on the steering wheel horn to warn pedestrians.
- Stopping requirements: A forklift moving at 10 mph may take 40 feet to stop. Studies have shown that a panic stop takes 1.3 feet for each mile per hour.
- Floor conditions: Slippery or wet floors make it more difficult to stop.
Forklift Safety Challenges: Inside the Trailer
Operating inside of a semi-trailer presents another safety challenge for forklift drivers. As is the case inside the dock, these challenges often revolve around miscommunication. One of the most common loading dock accidents happens when semi drivers mistakenly drive away while a forklift is still inside the trailer. Another common problem is "trailer creep," which occurs when trailers (particularly those with air-ride suspension) gradually edge away from the dock due to the repeated jarring impact of forklifts moving in and out of them.
In both cases, the first step in accident prevention is to secure the trailer to the dock using a locking device on either the trailer's rear impact guard (RIG) or rear wheel. Unfortunately, too many loading docks still use old-fashioned wheel chocks in front of trailer tires as a means of trailer restraint. There are a number of flaws with this "low tech" approach, including insufficient pullout resistance, chock slippage, and the time and safety concerns related to placing chocks by hand. Perhaps most importantly, chocks have no embedded communication system to let the driver, lift driver, and dock personnel know they are in place.
Rig-Based and Wheel-Based Restraints
Vehicle restraints using the trailer's rear impact guard (RIG) or wheels are a much better approach than chocks. RIG-based restraints have a full rotating hook that automatically locks to the trailer's RIG, utilizing the energy of the backing trailer. They are designed to help prevent all types of trailer separation including early departure, trailer creep, trailer tip-over (from landing gear collapse), or trailer up-ending. In addition, most RIG-based restraints also incorporate full-time communications systems that automatically show when a trailer is locked and safe to load or unload.
Unfortunately, conventional RIG-based restraints don't work in all situations. For example, docks that handle a large volume of trailers with hydraulic gates (such as retail, beverage, and grocery industries) typically can't use them because those gates block access to the RIG. Likewise, facilities that regularly handle trailers with damaged RIGs or RIG obstructions (such as axle-wide splash guards) can't use them.
Another consideration is international shipping container (intermodal) chassis traffic, which is projected to increase significantly in the next decade due to the Panama Canal expansion and other factors. Like hydraulic gate trailers, intermodal chassis also commonly have RIG obstructions. Fortunately, a new type of RIG-based restraint alleviates this problem. These newest models incorporate a "shadow hook" to offer another layer of protection, ensuring that the chassis is secured to the dock despite the obstruction.
Wheel-based restraints also can provide a solution for dock applications where RIG-based restraints won't work. They are compatible with virtually any trailer and, like RIG-based restraints, eliminate dangers associated with early departure and trailer separation. Importantly, many wheel-based vehicle restraints are equipped with communication systems using lights and audible alarms.
Communications At the Dock
For decades, the primary focus of communications at the dock has been on the locking status of vehicle restraints. The traditional vehicle restraint signaling system is a familiar fixture at plants and warehouses. These systems generally use green and red lights to indicate the status of the vehicle restraint or dock lock. A green light inside tells the forklift operator it is safe to enter a trailer because the restraint is locked and the trailer is secured to the dock. When the inside light is green, the light on the exterior of the dock is red, so that the truck driver knows not to pull away from the dock while the trailer is still being serviced. The lights are reversed when the restraint gets unlocked, letting the truck driver know it is safe to depart.
There is little doubt that vehicle restraint signaling systems contribute to a safe loading dock environment. However, forklift operators on a busy dock can easily overlook the status of a vehicle restraint, due to obstructions in their view of the control box when they are entering or exiting the trailer. For example, stacks of pallets in the staging area can block the view of status warning lights on an eye-level control box. Control box status lights might also get lost visually among several other control boxes or signs on the dock wall. And, of course, control boxes can't be seen from inside the trailer. In each case, the forklift driver becomes unknowingly at risk if the restraint becomes inadvertently unlocked.
Closing the Safety Gap
The newest communications technologies close this gap in dock safety. Some restraints can be equipped with advanced systems to further enhance the safety of trailer loading and unloading. In addition to performing the same functions as a traditional communication system, the most recent technology utilizes lights around the corners of the dock doors, providing clear communication of the restraint status directly in the forklift driver's line of sight and free of any visual obstructions. This technology also offers lights at the rear of the leveler to confirm the status of the dock lock to the forklift operator where there is the most risk -- inside the trailer. These light communication systems effectively mirror the red/green status of the control box, providing forklift drivers with another level of protection against catastrophic accidents caused by separation of the trailer from the dock.
Highly visible, low-voltage LED lights are used for these communication systems, as well as virtual filament technology that allows for significantly fewer LEDs per light. This provides a vibrant light-emitting element and also delivers clear directional light that minimizes light pollution.
LED lights in the upper corners of the interior dock doorframe provide a quick "status-at-a-glance" view for forklift operators so they know if the trailer is locked and safe to enter. It makes them more confident when entering a trailer, while lights on the leveler make them more confident while inside the trailer. In both cases, this makes them more productive. The leveler lights also offer a reference point for forklift drivers when they are backing out of the trailer.
OSHA and forklift manufacturers have made extensive efforts to improve the safety of forklift operation in and around industrial facilities and warehouses. However, the use of next-generation vehicle restraint and light communications technology will go much farther toward protecting forklift operators and pedestrians, reducing accidents, and improving productivity at the loading dock. While these new technologies mark a significant advance in loading dock safety, they cannot replace forklift and loading dock safety policies. Employers must continue to focus on forklift safety training and consider the use of multiple safety devices, such as strategically placed signs, painted aisles, and guarded walkways. The best practice is to seek the advice of safety consultants and qualified loading dock equipment representatives.
This article originally appeared in the September 2013 issue of Occupational Health & Safety.