"Muddy boots" mean more to Kenworth Trucks' engineers than a bit of dirt on steel toes. It represents research, feedback gathering, field testing, and experimentation. Boots might get muddy, but that comes with the job. The phrase is a company-wide concept passed down through Kenworth's 100 years in business.
The OEM's early engineers traveled to customer sites—which included many logging operations in the early days—to look at Kenworth trucks from top to bottom to see how they were holding up in the customer's application. These engineers' boots inevitably become pretty muddy.
Kenworth's "muddy boots" tradition continues to this day in multiple applications and environments: mud, snow, and concrete jungles. These engineers spend time with customers and drivers, learning their needs and desires. And they often get behind the wheel of the trucks themselves.
"It all begins with the 'voice of the customer'—hearing what our over-the-road, vocational, and medium-duty customers need from their trucks," said Kevin Baney, Kenworth GM and Paccar VP. "Building trucks is never static, and it's why we visit customers and have customer councils to keep the dialogue flowing and validation coming before we unveil a new product. Truck building is always evolving not only from a productivity standpoint—driving the cost of operation down—but in driver comfort and reliability. We continue to build what customers want and need."
Getting engineers' boots dirty out on the road
One way this is accomplished is through Kenworth's "Drive and Sleep" program, according to Joe Adams, Kenworth's chief engineer. Company engineers are encouraged to get a commercial driver's license to experience life on the road by driving the trucks they design. Putting engineers in trucks, often traveling great distances—to truck stops or remote locations—to interact with drivers in real-life situations, has been part of Kenworth's engineering process, dating back to its founding in 1923.
"It is said to truly understand a person, you must walk a mile in their shoes," Adams said. "For us here at Kenworth, we take that philosophy to heart in the importance we place behind the scenes in getting our engineers out to live in the shoes of our customers. We understand that drivers live and work inside our trucks, so what we learn on the road influences future modifications and assures that driving a Kenworth drives a better product."
Although the company has relied on customer feedback and in-field testing since its inception, it also uses modern technology to improve its trucks. The Paccar Technical Center, the product development and testing facility of Kenworth's parent company, also supports truck engineers. Kenworth takes advantage of this facility's ergonomics team led by Steve Jahns, Paccar's technical engineering manager for ergonomics and human-machine interface.
"Simplified, our group works with anything that has to do with the driver," Jahns said. "For example, we need to understand how drivers react to new displays and controls we're developing. Information should be accessible at a glance–driver distraction is real, and we develop and test to make sure whatever Kenworth develops is user-friendly. When it comes to comfort and actual driving, when I first started at Paccar, a truck would 'fit' about 60% of the driver population. Today, seat travel, visibility–even the angle of the pedals–comfortably fit 95% of the world population to make driving a truck more comfortable for every shape and size. Even seats are evaluated with pressure mapping and accelerometer monitoring for bounce. We want drivers to be as comfortable as possible."
Once the engineers develop concepts and prototypes through customer feedback and the technical center, they call on their customer council members—made up of real drivers and trucking companies—to test their new ergonomic ideas.
"I've been on the medium-duty customer council for eight years," said Craig Flintoff, VP of operations for Medosweet Farms, a company located in the Pacific Northwest that runs a mix of medium- and heavy-duty trucks . "Kenworth asked me to join the council since I know trucks, I'm opinionated, and I'm not afraid to share my thoughts, good, bad, or indifferent. Our drivers are also participating, and they recently provided feedback on new dash ideas Kenworth has been developing. They also took the time to drive with us during complex city deliveries to see how the trucks perform in tight constraints. Listening to customers and allowing us to be a part of the design process can only make for a better truck."
The Kenworth engineers aren't hands-off in the testing process. They continue to gather information from drivers and fleet owners on improving trucks even after that initial feedback.
"We routinely go out into the field and spend time with our customers," said Mark Wagner, Kenworth's assistant director of product planning. "All vocations are covered, and we dive deep to explore areas that can be improved upon. There are so many components that make up a truck and so many unique challenges our trucks undergo. Improvement is an ongoing process–something might work well for 99% of our customers, but we always strive to satisfy that last percentage point."
Driving Kenworth trucks from one extreme to another
That last percentage point includes fleets that run trucks in extreme conditions.
As chief validation engineer of the Paccar Technical Center, Steve Koeffler leads engineering teams into challenging environments to test and build trucks that perform well in harsh environments. Before a new truck is released to market, Kenworth tests the components inside and out.
In the winter, test drivers traverse roads near Yellowknife in Canada's Northwest Territories, a four-day, 1,400-mile trip from Koeffler's office at the Tech Center. At Yellowknife, the team targets temperatures as low as minus 40 degrees Fahrenheit, with the temperature in January averaging minus 20.
"The drive up to Yellowknife represents the unique road conditions many truckers face during winter," Koeffler said. "The day begins with cold starts in the morning. Then there are often snowstorms and ice buildup punctuated by occasional trips out of the rig to put on chains. Our drivers take notes on how the trucks operate and later write down observations to help engineers understand how the trucks are performing."
The team will drive up to 200 miles a day in Yellowknife, but it's the evening and morning that command the most attention.
"When we shut down, other truckers look at us like we're crazy," Koeffler said. "Truckers up there never shut down their engines due to the extreme temperatures, but we're testing cold starting and how systems function in bitter cold. We'll let the truck 'soak' for 12 hours, then do an unassisted cold start. We'll have a battery blanket and use No.1 diesel, but that's it–no fuel line or oil pan heaters. We're checking how the Paccar MX engine and supporting systems perform and how coolant is circulating–which will also thaw out diesel exhaust fluid."
Koeffler and his team also perform rigorous testing on the other end of the thermometer.
Death Valley, 282 ft. below sea level and 2,500 miles south of the Northwest Territories, experiences enough heat to fry an egg on a sidewalk. Koeffler takes his team to test Kenworths from Stovepipe Wells to Towne Pass, a segment of the Valley that features 8% grades and an elevation gain of 4,950 ft.
"It's a hard, aggressive climb to the top with a lot of shifting and strains on the cooling system, engine, transmission, and components," Koeffler said. "We'll start out when temperatures are close to 120 degrees, and at the top–some 17 miles later–it drops to 90 degrees."
After trucks prove themselves in the scorching heat, the team heads to Colorado and Eisenhower Tunnel. High elevation testing begins at Silverthorne with an elevation of 9,000 ft. From there, they ascend another 2,500 ft. to the tunnel. The team will also run trucks over to Loveland Pass, which, at 12,000 ft., is the highest point in the United States where commercial vehicles can legally travel.
"We're starving for oxygen at that elevation," Koeffler explained. "And it's a great test for the Paccar MX engines and turbos and figuring out ways to maximize engine performance. When you have one-third less oxygen, it can decrease your horsepower. We'll also test the components related to the engine and powertrain."
Just as in the company's early days, Kenworth engineers continue to get behind the wheel of the trucks they design. They meet with customers to understand specific requirements and determine ways to improve performance. And they test, and then test some more.
"Building a truck has certainly changed over the years," concluded Baney, who himself got "muddy" during his early years in engineering, culminating as Kenworth's chief engineer. "We've been true to our history in building trucks that meet and exceed our customers' expectations. That will continue in driving us forward over the next 100 years. I think engineers from the early days of Kenworth would be proud of what we've accomplished and how we've taken what they started and evolved the process into building the World's Best trucks."