Work Station Cranes vs. Standard Jibs: an Ergonomic Comparison
On the material-handling floor, it all comes down to being productive and profitable. But, due to the rising costs associated with workplace injuries, we can add “ergonomic” to that list as well. In fact, today, ergonomics—in this case, optimizing the interaction between operator and machine—is a key influencer for purchasers of manual material handling equipment.
Case in point: many employers are reducing workplace injuries in light- to medium-load-handling environments by replacing traditional manually operated I-beam jib cranes—the culprit of most push-pull repetitive-motion injuries—with more ergonomic work station cranes.
Out in the field, Gorbel’s Work Station Cranes are meeting the demand for ergonomic function and performance. The crane’s unique design allows for easier positioning and movement of product than standard jibs, making it perfectly suited for the easy transfer of loads, while minimizing common repetitive-motion injuries such as back, neck and shoulder strains.
As a leader in the materials-handling category and a proponent of ergonomic work station crane technology, Gorbel commissioned a third-party study in an attempt to quantify the ergonomic advantages of work station cranes over standard I-beam jibs. Here’s what they found:
In this study performed by the Rochester Institute
of Technology, manually operated, traditional I-beam
cranes were compared to Gorbel® Work Station Cranes
(WSC) in relation to push and pull standards developed
by Snook and Cirello (1991) for consideration by the
National Institute for Occupational Safety and Health
(NIOSH). This study consisted of two parts:
I. Compare the Snook and Cirello guidelines with the
type of push/pull forces experienced in industrial
conditions on I-beam and WSCs.
II. Determine the difference in productivity for both
types of cranes.
Ergonomics: The Great Equalizer
The first part of the study determined the gross force required by an average male and an average female to keep a load in motion (sustaining force) while safely* performing work at a sustainable rate on both types of cranes. The graphs below illustrate the sustaining forces for the subjects.
Ergonomics: Greater Productivity and Profitability
This part of the study determined whether an economically significant difference exists in the amount of work that an individual can accomplish in a typical work day using a Gorbel® WSC versus an I-beam crane. By measuring an individual’s work cycles (moving and positioning a load over a measured path) and keeping work intensity at a constant rate via a heart rate monitor, productivity could be accurately measured. Productivity of the male and female subjects are as follows:
In all cases, productivity levels of males using the Gorbel WSC increased by an average of 27%. Additionally, productivity for female subjects increased by 28%.
Enhanced performance with a Gorbel WSC results from the ease of movement associated with a WSC’s design. Reduced dead weight and a design superior to that of the I-beam crane result in reduced coefficients of friction and lower initial and sustained movement forces that allow workers to position and move loads on Gorbel WSCs more easily than on I-beam cranes
Work station cranes improve productivity, profitability and safety.
In summary, the study revealed that workers using manually operated bridge cranes can safely handle significantly more weight with a Gorbel Work Station Crane than with a traditional I-beam jib crane. Additionally, the facts show that operators of these systems can do their jobs better, faster and for longer periods without fatigue or discomfort. Consequently, the simultaneous increase in productivity and reduction in job-related injuries can positively impact the bottom line of today’s materials-handling companies. To find out if a work station crane is right for your application or to arrange a local demonstration, call Centex Material Handling at (512) 337-8181.