Issue link: https://read.dmtmag.com/i/764523
Bowman says that today ergonomists get involved at the ground level when vehicles are being developed. Ergonomists have to be aware of the changes in the trucking industry that may affect the ergonomics of the truck, whether it is a shift in the physical size of the driving population or the changing demo- graphics of the driver population. They also have to be mindful of the trucks' application. To do this they are in continuous contact with drivers. Sitting down with drivers to dis- cuss their needs is one option, but Bowman, who has had a Class A CDL for more than 10 years, says, "There is nothing better for understanding how a vehicle is used than going out there and using it yourself." And, according to the Department of Health and Human Services' anthropometric study, "If design is poorly fitted to size and dimensions of drivers, the road may be less visible, con- trols may be more difficult to reach and seat belts less comfortable." Bowman explains that it is important for information to be gathered when the vehicle is in its conceptual stage. "We sit with the engineers and designers when the pencil first hits the papers," he says. "We actually are involved throughout the entire design process as we develop the requirements that repre- sent the driver, we hold engineers account- able to those requirements and we test for those requirements at the end before the vehicle is released to the market." Stu Russoli, highway product manager for Mack, says two things come to mind when he thinks of ergonomics: design and driver's perspective. "From a design perspective when we design, redesign or even move anything around in the cab we evaluate it in several ways. We digitally examine the areas affected making sure the work flow, reach, visibility, interferences from other equipment such as the steering wheel, brake controls or even the cup holder don't interfere with line of sight or reach," Russoli says. Then Mack develops a test rig in order to physically try out changes using engineers and other internal personnel specifically selected for their diversity of size. The study considers all sizes of male and female drivers. Using a survey, everyone reviews the same feature, for comfort, reach and visibility. "Finally depending on the impact of the change — are we moving the radio to accommodate a shift pad or are we redesign- ing the entire dash — we bring in industry drivers to make the final evaluation in a simi- lar manner to our internal survey and possibly test driving the complete vehicle to evaluate comfort and real-world use," he explains. When most people think of ergonomics, they immediately think of seats, but ergonom- ics plays a much bigger role in truck design than that. Ergonomics can be applied wher- ever there is an interface between the driver, operator, the technicians and the vehicle. Understanding ergonomics Ergonomics is essentially the study of work. "Ergonomics is understanding what the per- son does, whether it is the driver, the operator or the technician, and then matching it with the engineering and design of the vehicle," Bowman explains. It includes understanding the goal of the task being performed and then relating that information to the engineers and designers so they can incorporate it into their concepts. Failure to consider ergonomics in vehicle design means there may be a mismatch between the vehicle and what the operator wants to do. Poor design can cause frustra- tion, errors and discomfort. From a physical standpoint, if the truck design is not matched up with the size and shape of the driver, he or she can experience biomechanical discomfort including aches and pains. That discomfort can contribute to driver fatigue and even turnover. "If it is not an ergo- nomically designed truck, it may impact the driver's willingness to operate that truck for longer periods of time," Bowman says. On the flip side, Bowman says a truck with well-de- signed ergonomics that is suited to their capa- bilities and physical dimensions means the drivers enjoy operating the vehicle. Given the current and projected driver shortage, keeping drivers happy and comfortable has become even more important and has placed more pressure on getting vehicle cab design right. Shedding light Truckers have a variety of lighting needs inside the cab and the color, type, position and intensity of the lights are important ergonomic considerations. For example, when filling out paperwork on the steering wheel, the light should illuminate the workspace and not come from a typical dome light that may cast a shadow on the paperwork. A passenger light should not obstruct the view of the driver and should have individual controls. Russoli says all of these lighting features are included in the Mack cab, along with general light and read- ing lights in the sleeper and red floor lighting options for customers who prefer dimmer light at night. Reducing vibrations Truck makers have been working hard to reduce noise, harshness and vibration in the cab in an effort to create a more comfortable ride. By the very nature of their work, truck driv- ers are exposed to whole-body vibrations, which can lead to muscular and skeletal issues. The Washington State Safety and Health Assessment and Research for Prevention Program and the Trucking Injury Reduction Emphasis Group says, "Work-related COVER STORY "There is nothing better for understanding how a vehicle is used than going out there and using it yourself." Darrell Bowman, engineering lead for ergonomics at Mack Trucks 8 | B U L L D O G | 2 0 1 6 V 3