Opening the door to visual communication

by Katie Daniel | December 5, 2016 10:31 am

By Jon Schumacher
With today’s highly competitive, time-sensitive global economy, the demands on warehouses, distribution centres, and production facilities are more intense than ever before. Productivity and efficiency are at a premium, with the pace of operations at an all-time high. Improvements in industrial technology have allowed many facilities to keep pace with these demands and, in many cases, have pushed the pace to even greater speeds. (For more on high-speed doors see this author’s previous Construction Canada article, “Understanding high-speed doors and Industrial Curtains.”[1]) It is important for building designers and specifiers to be aware of this ever-increasing pace, and to accommodate for it when selecting products.

High-speed doors are a good example. The most advanced high-speed doors can operate up to 2.5 m (8 ft) per second, and roll-up models use very little wall space because they are upward-acting unit with the curtain collecting in a head assembly at the top of the door when it is opened. By comparison, a rigid-panel door that opens from the centre requires considerable wall space on each side of the door to function. For example, a door spanning a 1.8 m (6 ft) opening requires approximately 0.9 m (3 ft) of wall space on each side so each panel has a place to travel when opened. Roll-up doors reduce the physical footprint necessary in a facility while simultaneously providing quicker cycle times.

Major advances in door design have focused on insulated upward-acting doors. New, technically advanced doors have the ability to withstand forklift impact—minimizing maintenance and downtime while maintaining a tight seal over the life of the door. These ‘impactable’ doors can re-align on their tracks easily if they are dislodged, ensuring productivity does not take a big hit after the door takes one.

Some door models offer higher R-values (conduction), reducing the need for heated panel defrost systems. Other models offer torque-sensing reversing capability, to help eliminate safety and maintenance concerns with doors using pneumatic or electrical reversing edges for the same purpose. Another safety feature includes use of ‘soft-edge’ technology to ensure workers are not severely injured, and equipment or products are not damaged, if struck by a door.

However, additional safety devices are just catching up to another potential danger of high-speed doors—collisions in the threshold of a just-opened door.

Blind spots, forklifts, and pedestrians
While some operations can allow for windows or viewing panels in the door, not all do. Not knowing what is on the other side of the door—more specifically, what is moving toward the door—can create a potentially dangerous situation. A forklift with a load approaching a door from one side and a worker entering the same door from the other can be a risky prospect.

The Occupational Health and Safety Council of Ontario (OHSCO) reports there are nearly 800 forklift related incidents in a year—more than two every day. Obviously not all these incidents are caused by blind spots created by doors, but some certainly are.

In Ontario, the average time lost due to forklift incidents is 67 days, according to Workplace Safety and Insurance Board (WSIB) statistics. Forklift accidents are not only a safety issue, but they are also financially damaging. Workers’ compensation claims from these incidents cost employers millions of dollars every year, and time is also lost due to accidents halting productivity and slowing operations.

The inherent dangers with operating forklifts caused regulations and guidelines to be put in place. First and foremost, all forklift operators must receive training and be certified. During training, workers will learn to operate forklifts safely and about the proper precautions to take when operating a forklift. In the United States the Occupational Health and Safety Administration (OHSA) advises:

• the truck be operated at a speed permitting it to be brought safely to a stop;
• the operator slow down and sound the horn at cross aisles and other locations where vision is obstructed; and
• the operator look forward and keep a clear view of
  the travel path.

These general practices also make sense in Canada, but they are not necessarily followed in every single instance. Additionally, trying to manoeuvre a forklift in tight confines, often under impending deadlines and dealing with a variety of other challenges, can make it difficult to maintain awareness of pedestrians and bystanders.

For forklift operators, there is a balancing act—safety regulations and protocols encourage them to operate with caution, while production goals push them to work as quickly as possible. It is the operator’s responsibility to make the right decisions. This is why operator training is mandatory.

Even the best-trained forklift operators must deal with certain realities. Approaching a closed door is one of them. Other common challenges include:

• unexpected entry—when workers on foot or another forklift might be using the same door;
• open staging areas—when areas in front of doors allow unrestricted movement of forklifts, as well as workers who are on foot;
• difficulty hearing—when wearing hearing protection can impede a worker’s ability to hear audible devices or sense where the sound is coming from;
• stopping requirements—when a forklift moving at 16 km/h (10 mph) may take 12 m (40 ft) to stop (studies have shown that a panic stop takes
  0.2 m/km/h [1.3 ft/mph]); and
• floor conditions—when slippery or wet floors make it more difficult to stop.

Light communication improves safety
The blind spots created by closed doors represent a danger not too dissimilar from blind spots created at loading docks. Vision can be severely hindered inside a trailer, where forklift drivers are essentially operating inside a tunnel. This creates a dangerous blind spot for the operator 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.

Simple light communication technology began appearing in loading docks across North America in response to these dangers. Now, vehicle restraint signaling systems contribute to a safe loading dock environment with an easily understood red light/green light system to indicate when a trailer is secured at the loading dock. The newest communications technologies use advanced systems to further enhance the safety of trailer loading and unloading. For example lights around the corners of the dock doors provide clear communication of the restraint status directly in the forklift driver’s line of sight.

This technology also offers lights at the rear of the leveller to confirm the status of the dock lock to the forklift operator inside of the trailer where there is the most risk. Located within the leveler, these light communication systems effectively mirror the red/green status of the control box, providing forklift drivers and other nearby personnel with another level of protection against catastrophic accidents.

Light-emitting diodes (LEDs) 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 leveller make them more confident while inside the trailer. In both cases, this makes operators more productive.

Similar types of light communication systems are migrating to the inside of facilities, especially where blind spots like doors exist.

Door communication inside a facility
Many facilities use mirrors for blind corners and traffic signs at intersections and doors. Unlike mirrors, which can provide a real view of obstacles and workers, traffic signs merely offer safety advice. Workers who approach a door with a ‘slow’ sign will not always heed its warning, especially if they have gone through the door hundreds of times without an incident.

Some light communication systems are providing an additional layer of security. Pre-announcing when a door is about to close using strips of light-emitting diodes (LED) lights on either side of the door. When a door is about to close, the lights will flash yellow. When the colour of the lights turn red, the door is closing. This system is good for alerting workers when to avoid passing through a door opening in a facility.

Counting down in 2016
Another light communication system being used is a countdown system. Similar to the flashing yellow and solid red lights of the pre-announce system, this light communication system alerts workers when an open door is about to close.

However, instead of coloured lights, a number countdown appears in an easily viewed location near the door, like a crosswalk countdown at a busy street intersection. The countdown can be set as high as 99, although most facility managers set a range under 15 to help regulate traffic flow. The numbers will appear white all the way down to 3, but then change to yellow on 2 and 1. Once the countdown is complete, a red arrow points down to signify the door is about to close. Motion sensors allow workers to re-activate the door at any time, which restarts the countdown sequence.

Much like a pre-announce system, this type of light communication system is great at letting workers know when a door is about to close.

Virtual vision is right around the corner
Although there are safety benefits to both of the aforementioned light communication systems for high-speed doors, neither allows workers to ‘see’ what is on the other side of a door. Systems alerting workers on one side of a door if something is approaching from the opposite side are now being made available. Knowing if something is about to enter a door can prevent a host of potential accidents, including a forklift/worker collision at the entryway.

This light communication system uses the same type of motion sensors high-speed doors use for opening and closing. Once these motion sensors detect a person or forklift approaching, flashing red LED light strips on the opposite side of the door appear to alert personnel that the door is about to open. These LED alert strips can be placed on the outer portion of the door or wherever they are most easily viewed by workers.

In addition to high-speed doors, this virtual vision light communication system can be used in other applications where blind corners exist, such as hazardous intersections, aisle ends, or anywhere else in a facility with less than ideal vision.

Improving safety around high-speed doors
High-speed doors have brought several benefits to facilities across North America and the world—increased productivity, better operational efficiencies, and safety. As these types of doors become more ubiquitous due to these benefits, it is important for safety around high-speed doors to keep up. Just as loading docks have become safer places with light communication systems, soon the areas around high-speed doors will follow. One should be sure to stay up with the latest trends in door safety and talk with door experts to find the best solution for the facility.

Jon Schumacher is the director of marketing for Rite-Hite Doors. He has been with the company for 20 years and is the vice-chair of the Door and Access Systems Manufacturers Association (DASMA). Schumacher can be reached via e-mail at jschumacher@ritehite.com[2].

Source URL: https://www.constructioncanada.net/opening-the-door-to-visual-communication/

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