The need for speed will continue driving material handling and warehousing technology and innovation. While there is a great deal of hype and excitement associated with some of the technologies developed to meet that need, there should be questions and concerns about how the advances will affect worker safety. The use of automatic guided vehicles (AGVs) and automated loading docks provide a good example.
Flexibility and intelligence are enabling AGVs to pick and place from multiple and variable locations. Tomorrow’s AGVs will benefit further as more advanced guidance systems are refined and justified to interface with evolving warehouse management system (WMS) technologies. The focus is already shifting from guidance systems that detect obstacles to open path systems that flexibly avoid obstacles while carrying out more complex material handling tasks—including loading and unloading trailers.
AGVs come in a variety of sizes and shapes to serve different purposes—lift trucks (a.k.a., driverless forklifts), tuggers, carts, and pallet jacks are but a sampling of the growing market. Automated lift trucks find their roots in two basic platforms—those that were designed from the ground-up to be driverless (e.g., no driver’s compartment or controls) and convertible models. The convertible models automate traditionally designed lift trucks and maintain the flexibility to be used as an automatic vehicle or can be toggled to allow an operator to drive the lift truck. Semi-automatic operation of convertible models is also possible.
Safety standards are evolving to guide development of AGVs, but ANSI/ITSDF B.56.5, “Safety Standard for Guided Industrial Vehicles and Automated Functions of Manned Industrial Vehicles,” serves as the lynchpin. Supporting standards provide guidance about the design, maintenance and use of individual components of the AGVs. A prime example is IEC 61496-3, “Safety of Machinery—Electro-Sensitive Protective Equipment—Part 3: Particular Requirements for Active Opto-Electronic Protective Devices Responsive to Diffuse Reflection.” This document provides guidance on the design of safety laser scanners which react to obstacles, including workers and pedestrians, that may be in the path of the moving AGV. These scanners can issue commands that quickly stop the vehicle before contact is made.
Nevertheless, new questions about worker safety will be raised. Current OSHA standards will be limited in their application. Fundamentally, all relevant OSHA requirements for general industry are summarized in 29CFR 1910.178, “Powered Industrial Trucks” (PIT). This standard addresses design, usage, training, application (i.e., use of PITs in hazardous locations), inspection and maintenance requirements. But, the standard was written with the assumption that PITs would be manned.
One could make an argument that existing OSHA requirements for PITs would not go far enough to control the risks associated with operating AGVs. For example, 29CFR 1910.178 has no cross-reference to the requirements in ANSI/ITSDF B.56.5 or IEC 61496-3.
Another example relates to worker training. Existing OSHA training requirements for PIT operators would have limited application (would only apply to convertible models), but don’t begin to address the training needs of workers who could actively interface with AGVs in non-restricted work areas. These exposed workers need to understand how AGVs operate and how to safely interface with them. Training requirements for interfaced workers are outlined in ANSI/ITSDF B.56.5 and would seemingly need to be addressed by OSHA.
Current OSHA standards have no requirements about how AGV travel should be controlled, how areas employing AGVs should be placarded, what warning devices must be present on AGVs, or how loads carried by AGVs must be stabilized. These and other important topics need to be considered in order to preserve and promote worker safety.
Automated Loading Docks
Loading dock automation must effectively deal with long-standing concerns about trailer/dock separation. Trailers that “creep” from dock doors during the loading/unloading process or that are prematurely pulled away by tractors can expose lift truck operators to serious or fatal injuries if their lift trucks fall to the dock apron. While trailer/dock separation is less of a worker protection issue with AGVs, protection would still be demanded to maintain safety and efficiency.
Many of today’s and tomorrow’s trailer designs (air-ride, low-boy, lift gate, and drop frame trailers) challenge the effectiveness of hook restraints. Hook restraints will not work with many future trailers. This is opening the door for “trapped key glad-hand locks” to play a greater role in automated loading dock safety. These systems use unique keys to lock trailer glad-hands after the air hose between the tractor and trailer is disconnected. When the air is disconnected, trailer brakes are automatically engaged until air pressure is restored.
Many glad-hand lock systems already comply with current OSHA requirements defined in 29 CFR 1910.178(k)(1) and (m)(7) and applicable letters of interpretation. This flexible technology appears well positioned to interface with automated loading docks, including expanded use of AGVs for loading and unloading of trailers.
Russ Wood is a communications manager at Omron STI (www.sti.com).
The Elements of a Good Safety Pro gram
By Kyle Oslos and Dixie Brock
There are two ways to make sure a company stays on the right side of OSHA: Know the regulations that apply to its industry, and do everything to create the safest possible working conditions for employees. These two guidelines form the basis of a solid safety program that incorporates the following key elements:
Frequent forklift safety training: OSHA requires that all warehouse forklift operators receive forklift safety training at least once every three years. We recommend forklift operators receive safety training every year, and include in that training things like pedestrian safety.
Heightened ergonomic awareness: Train managers, supervisors and warehouse employees on everything from recognizing the risk of repetitive motion injuries for people working on pick lines to the importance of using safe lifting and material handling techniques that prevent back, neck and muscle strain. This training can help reduce injury rates, leading to fewer missed days of work and overall improved morale.
A strong focus on data collection and analysis: Keeping thorough injury records will give visibility to worker’s compensation claims and an unvarnished view of exactly which kinds of accidents lead to the greatest number of claims and expenses.
Strong employee involvement: Some of the most memorable and effective training materials can come directly from employees in the field. Newsletters, games, posters, slogans and special events developed by a safety committee can go a long way toward keeping safety top-of-mind.
Acknowledge accidents: If a facility has an accident that results in a fatality or a hospitalization of three or more people, OSHA insists on knowing. Not only that, federal OSHA standards require companies to notify it within eight hours, and some state OSHA plans are even stricter than that. (OSHA is currently considering the tightening of these standards to state that it must be notified in the event of any accident that leads to even one hospitalization as well as any accident that results in an amputation, so check www.osha.gov to stay up-to-date.)
Another important group deserves to know in a timely fashion: upper and warehouse management. Although it’s best to protect the identities of the parties involved and never share specifics about which employees were injured—in adherence to all privacy laws—such incidents can serve to remind management of the risks associated with a particular process or piece of equipment and the corrective action they can take.
Clear hazard communication: OSHA guidelines clearly state that companies have an obligation to communicate the presence of hazards to employees in a variety of ways, including signs that are posted prominently in each facility.
These prompts can also take the form of safety banners that are displayed in various areas or traffic reminder signs hung at key “intersections” within the building. Prompts can also mean painting a facility’s uprights an unusual color like pink to reduce the risk of forklift-upright collisions.
Final words: OSHA issued nearly 600 safety citations to SIC code 4225 between October 2009 and September 2010. Whether your company has been cited numerous times, or not at all, it is still a prime candidate for a more proactive, formal safety effort.
Kyle Oslos is director of logistics for APL Logistics, and Dixie Brock is the company’s national warehouse safety manager. APL Logistics provides warehousing and other supply chain management services (www.apllogistics.com).
Make the Loading Dock Safer
By Michael Brittingham
The American Society of Safety Engineers offers suggestions to increase safety for an aging workforce, and all of them apply to the loading dock:
Think ergonomically: Providing a solid, safe and sure bridge from the dock to the truck trailer is a primary element of any dock safety program. However, some edge-of-dock levelers, mechanical levelers and dock plates present ergonomic risks for older bodies. Consider using air, electric or hydraulic powered dock levelers to reduce physical strain on employees.
The dock door is susceptible to forklift hits, making the door difficult to open. Impactable dock doors prevent misalignment issues, allowing workers to operate the doors more easily.
Improve illumination and hazard warnings: Overhead lighting cannot shine into the truck. Proper dock lighting prevents tripping over objects or slipping on grease slicks. LED bulbs provide longer life for dock lights, and when used on communication systems, prevent serious risks such as trucks pulling away before loading/unloading is finished. In addition, dock impact barriers, designed like a gate, pivot up for doorway access and latch in place to prevent forklifts from tumbling off the dock. Bright yellow netting also alerts the driver to an open doorway.
Remove clutter from control panels: Panel faces designed for older workers and those who use English as their second language can make equipment operation training faster and easier, and enable docks to avoid damage due to deployment at the wrong time.
Make floors skid resistant: To avoid mixing moisture, debris and grease on the floor the dock must be tightly sealed. Door damage can lead to gaps between the door panels and frame, letting out conditioned air but letting in dirt and moisture. Also important is providing a seal around the truck trailer parked at the dock. Pay special attention to seal/shelter durability if truck traffic involves one trailer after another pulling up to the dock.
High Volume Low Speed (HVLS) fans can also help prevent slippery floors by effectively circulating the air in a facility, reducing moisture buildup and protecting both workers and products.
Michael Brittingham is a manager at 4Front Engineered Solutions (www.4Frontes.com).