So much of our daily routine is controlled by automated technology that we don't even think about it. Our alarm clocks wake us up; our pre-set coffee makers kick into action; our automatic door locks make getting into the car easier than ever; and, thanks to our automatic transmissions, we don't even have to shift while driving. And all of that is before we even get to work!
But these kinds of automation technologies aren't just revolutionizing the consumer world; even industrial facilities are experiencing it. Facilities are becoming increasingly automated, with advanced robotics, AS/RS systems, AGVs and warehouse management systems. Yet, despite these 21st-century innovations, many loading dock operations still rely on manual labor and outdated, 20th-century technologies. But even that is changing, as products like interlocked, integrated loading dock control systems are becoming more widespread.
Automating the Loading Dock
At many facilities, the various pieces of loading dock equipment – including vehicle restraints, levelers and overhead doors – are operated independently of each other. Once upon a time, these operations were all manual operations, such as the setting of wheel chocks on a trailer's rear tires once it is positioned at the dock. These operations not were only time-intensive (requiring employees to go outside and set the equipment), they potentially were dangerous, with a host of potential accidents caused by human error.
Today's leading loading dock control systems do away with this danger by automating the loading and unloading process with just the touch of a button – starting with the vehicle restraint. Restraints that require minimal human interaction to automatically secure a trailer or vehicle that backs up to the dock increase efficiency and safety by eliminating the need for dock employees to go outside and physically secure the trailer. They also eliminate the opportunity for mistakes by the driver, ensuring the trailer can't mistakenly pull away when a forklift is still inside.
Automatic restraints can work by locking onto the trailer's wheels or – more commonly – its rear impact guard (RIG). RIG-based automatic vehicle restraints offer a RIG/restraint vertical engagement range of 9 to 30 inches. Some models even can help secure intermodal overseas container chassis, which are increasingly common across the supply chain.
Additionally, some automatic restraints can be integrated into building management or security systems, providing another level of security and protection against external tampering.
Advanced Safety Systems
Engagement of the restraint triggers a dock safety communications system. The traditional signaling system is a familiar fixture at plants and warehouses, with green and red lights indicating the status of the vehicle restraint. Inside, a green light tells the forklift operator the trailer is secured and safe to enter. Outside, the light turns to red, letting the truck driver know that it is not safe to pull away from the dock, as the trailer might still be getting serviced. The lights are reversed when the restraint gets unlocked, telling the truck driver he safely can depart.
The most advanced light communications systems offer well-placed, at-a-glance lights that are easy for lift truck drivers to see. Due to obstructions in their view of the control box, forklift operators easily can overlook the vehicle restraint status 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 also might get visually lost 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 unknowingly becomes at risk if the restraint becomes inadvertently unlocked. Advanced light communications systems provide visual cues for the forklift driver on a sight-line above the control box and at the corners of the door opening, as well as on the dock leveler, providing visual verification from inside the trailer.
The newest dock controls go well beyond light communications. They now can be programmed to operate only in a safe sequence of operation, with individual elements of the system interlocked. For instance, the most advanced dock control systems can be programmed with a green light interlock, which disables the use of the hydraulic 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 safely is stored before the restraint can release the trailer. If an inexperienced 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.
Barriers positioned near the edge of the dock door to prevent falls out of the dock opening also can be integrated into this safe sequence of operation. Once the trailer securely is in place, the lock button is pressed, the light on the control box turns green and the barrier releases for easy access to the trailer. The most advanced barriers – made from PVC-coated fiberglass mesh and heavy-duty polyester – can stretch across openings 16-feet-5-inches wide and are able to stop up to 30,000 lbs. with minimal damage to the barrier.
Like smartphones, these advanced control systems use a touchscreen interface. However, they also are built to withstand the harsh conditions on a loading dock; meet requirements for electrical noise; electrical and environmental conditions; and chemicals. In addition, they have flexible circuitry and can be modified to update components or add features well after original installation.
Automating Environmental Control
Temperatures in loading docks notoriously are hard to moderate due to constantly opening and closing doors, particularly in locations that have large seasonal variations or big temperature swings throughout the day. Fortunately, smart automation tools for controlling internal environments also are becoming more widespread. Control systems for high-volume, low-speed (HVLS) fans are an example of this.
By destratifying conditioned air, HVLS fans can be used to moderate temperatures on a seasonal or daily basis. During winter, the correct fan speed produces even temperatures from floor to ceiling, allowing for significant energy savings (through lower thermostat set-points) and increased employee comfort. In summer, an automatic and accurately controlled fan speed results in a cool breeze when it's needed most.
The leading HVLS control stations not only adjust a fan's speed to match outside conditions, they can control up to 18 fans at a time – turning them into a truly integrated network. These intuitive and touch-screen controls not only maximize the energy savings and comfort the fans deliver, they also enhance operational efficiency by eliminating the need to visit multiple fan locations to make adjustments. In addition to simultaneously controlling fan speeds and usage, they allow users to schedule fans to operate only when needed (thus saving energy), customize each fan's settings name to specific building locations and immediately see the settings and status of each fan in the controlled system.
HVLS fan systems also can be networked with building control systems, so users can coordinate the operation of the fans with other building functions. And safeguards are built into the system, like an internal battery that retains custom settings in the event of a power failure. Additionally, control boxes used to relay signals to and from the main control station can be mounted high on walls or columns to avoid damage and minimize the cost of wiring.
As new technologies like interlocked loading dock control systems and HVLS fan network controls continue to emerge, loading docks and warehouses quickly will catch up with internal manufacturing operations in terms of “automating-in” safety, efficiency and comfort. While many of these systems are relatively new, expect to see them become increasingly abundant in the coming years.
Troy Bergum is a product manager at Rite-Hite, which has over 45 years of experience providing solutions at the loading dock and throughout facilities for maximum safety, efficiency, energy savings and productivity.