MATERIALS HANDLING
Return rollers over travelways can fall and produce a potential hazard
be located. Some jurisdictions specify the hazard must be at least 2.1m (7ft) from the work surface or floor; other regulations require greater distances.
WORKER RISKS FROM GUARDING BY LOCATION By determining a general safe height for all locations, some workers may be safeguarded while others are not. Taller employees – 1.82m (6ft) in height or more – can easily suffer an injury reaching up into a moving component that is 2.13m (7ft) above the ground. Working above machinery that is considered guarded by location exposes workers to increased severity of injury if they slip or fall to a lower level. A fundamental problem for conveyor designers is the absence of specific global standards. Without uniform standards, equipment that is manufactured in one country to be installed in a second country may not be compliant for transfer or resale in a third country. Te variation on standards from 2.1 to 3.5m (7.0 to 11.5ft) is too much to assure global compliance. Further, most regulations do not
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account for the potential build-up of spillage underneath the conveyor or in walkways, which can easily change the distance between the working surface and a hazard. It’s also fairly common practice to purposely collect a pile of material or fill a bin to gain access for service or inspection of an elevated component. Using tools and methods that extend a worker’s reach while the belt is running is a hazardous activity that can contribute to serious – and possibly fatal – accidents.
GUARDING BEST PRACTICES Exemptions such as guarding by location do not fully address the dangers explained above. As a result, rules defining the practice become ineffective as a safety measure, especially where belt conveyors are concerned. Despite its acceptance in various regulations, the practice of calling moving components on conveyors ‘guarded’ solely because their installation is at least a specific distance from the worker(s) is outdated as a concept and ineffective in application. It should be discontinued.
Te logical solution is to simply install guards and baskets to protect workers
from lateral and overhead hazards, while still offering safe and easy access. For maximum risk reduction, all nip points, shear points and moving or rotating components should be guarded, regardless of location or access. Many vendors can fabricate and supply guards of all types to fit virtually any application needed.
PUT AN END TO THE MYTH Despite its nearly global acceptance as a concept in industrial safety, the practice of guarding by location remains a particular problem for overhead conveyor applications. It’s time to accept that as far as conveyors are concerned, ‘guarding by location’ is a myth. As such, it’s a concept that should be abandoned to make conveyors – and those who work on and around the equipment – safer.
Daniel Marshall & R. Todd Swinderman are with Martin Engineering.
www.martin-eng.com
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