In today’s market, it is especially important to consider specifying your next new dump truck with both vehicle productivity and driver comfort and satisfaction in mind.
Bed materials, shape, capacity, and other features help determine a truck’s productivity. If your choice of dump body helps to haul a half-ton more than the next guy, you’re not just going to be more profitable but that half-ton is going to win you contract after contract over the vehicle’s life. But payload is only part of the equation.
“The biggest trend in dump truck design is driver comfort and satisfaction,” says Kevin Baney, chief engineer at Kenworth Truck Co. A larger interior, a more logical dash and switch layout, better braking performance, and information centers with instant feedback are features that can improve the driver’s experience both on the road and at the jobsite.
“The body builder largely defines a vehicle’s allowable payload based on what and where you’re hauling,” Baney explains. “But the cab and chassis play a vital role in keeping drivers happy and productive.”
Many of these design elements have evolved over the years, especially as truck manufacturers account for the wider variety of body types and experience levels in the workforce. Here are six features to help truck owners focus on filling both the driver’s seat and the dump bed:
1. More Interior Space
A cab should also accommodate the personal equipment an operator uses on the job. There are three ways to create more space in a cab:
Increase the length and width.
- Eliminate clutter and protrusions on the floor.
- Optimize the seating position for clean sightlines.
“Visibility is one of the most important operating features at a jobsite,” says Baney. The combination of a tall windshield and lower windshield base in the Kenworth T880 vocational truck resulted in a 50% larger windshield than the previous generation cab, giving the driver a better view of the terrain, obstacles, and workers around the truck.
“The interior should accommodate and adjust to a wide range of body types and sizes,” Baney says.
Engine technology has evolved, and truck owners who aren’t aware risk specifying more power than they need. “A 13-liter engine, with the proper power band, can rival a 15-liter engine in many vocational truck applications,” says Baney.
Nor does a 13-liter engine limit your choice of transmission. Baney says Eaton’s 8LL and 18-speed manuals remain leading specs among dump truck buyers at Kenworth, but the need to attract and retain drivers is pushing the industry toward automated and automatic transmissions. Operating a manual transmission requires more effort and concentration on the road and in the work zone.
3. Braking and Stability Control
Many dump truck owners previously considered front disc brakes a delete option but that’s changing. “While drivers appreciate the performance of disc brakes and owners like the ease of maintenance and light weight, both are also keenly aware of the scrutiny dump trucks face from inspectors,” Baney says. Drum brakes were once again the No. 1 out-of-service item during roadside inspections, according to Road Check 2014 performed in North America by the Commercial Vehicle Safety Alliance.
“The advantage with disc brakes is that pad and rotor wear is far easier to see during a driver’s pre-trip — there’s no crawling under the truck. Drivers say they feel more confident when they pull into an inspection station with a disc-brake-equipped dump truck,” says Baney.
The combination of disc brakes and a 6S/6M ABS configuration (six-wheel speed sensors and six modulators that transmit pulsating air when a wheel locks) provides all-wheel and individual-wheel braking control. Because it can respond to each wheel individually, ABS provides better performance in split-coefficient situations where one wheel is on a slippery surface like a steel plate and another is on dry pavement.
Finally, advanced braking systems can provide active safety features like roll and directional (yaw) stability control. “Dump truck loads are dynamic — they move — and no two payloads are placed exactly the same,” Baney says. “Drivers who have experienced advanced braking systems on highway trucks want the level of control that disc brakes and active safety systems can provide.”
4. Information Centers
Dump trucks are supplementing traditional dial gauges with data-rich digital displays. The Kenworth T880 is one example. Centered above the tachometer and speedometer is a 5-inch, high-resolution, color display. Digital gauges provide general information like time and temperature but also real-time information about the truck’s operation, including oil and transmission temperatures, a sweet-spot visualization of RPM and fuel economy, engine torque, PTO status, and pop-up diagnostic alerts.
Some new truck models also now incorporate a hands-free communication system with Bluetooth connections and voice commands as well as turn-by-turn navigation, USB port, camera inputs, AM/FM/weather bands, and iPod or MP3 integration. Kenworth’s system offers up to 30 virtual gauges in the screen to supplement the dash gauges.
“On the highway, the driver wants instant feedback about the truck’s operation. In the work zone, the driver’s needs to concentrate on the status of the payload, PTO, dump bed, and what’s happening around the truck,” Baney says. “The idea is to give the driver the right information at the right time for enhanced productivity.”
Using electric-over-air (EOA) switches to control air solenoids (which control PTO engagement) provides new control and interlock opportunities. In the past, safety interlocks were manually installed by the body builder through solenoids, micro switches, and relays. Today, EOA switches allow the truck manufacturer to take advantage of the truck’s ECUs and provide electronically controlled safety interlocks from the factory.
“With EOA switches, we can program it so if a certain condition is not met, the switch will not activate the component on the truck,” Baney says. It’s useful, for example, for the ECU not to allow the PTO to function unless the parking brake is set, preventing the dump bed from raising accidentally.
EOA switches also keep air lines for transmission PTO controls from routing inside the cab, eliminating the noise that comes with air-actuated switches.
Part of the HVAC system, automatic temperature control uses a computer and sensors to monitor temperatures and humidity levels inside and outside the cab at duct outlets and at the evaporator. It can fine-tune the temperature inside the cab automatically, controlling which ducts the hot or cold air blows out of, as well as the fan speed and the position of the recirculation door.
One factor in HVAC performance that’s often overlooked: the door seals. “A more robust seal design will help maintain pressure inside the cab,” Baney explains, “keeping out dust, dirt, and other airborne particles that can irritate the driver and interfere with the performance of the air conditioner.”
The truck OEM, truck dealer, and body builder work together to produce a truck that’s capable of being productive and profitable. Once that truck is delivered, the driver is most responsible for making sure those plans are realized.
“For years, when fleet owners took delivery of a new dump truck, their first thought was about how to fill it,” Baney says. “Now they have to think about where to find a qualified driver. When you spec your dump truck starting with the body, consider first which body matters most.”
See also: Tips for Spec'ing Ready-Mix Mixers
Five tips ready-mix haulers should follow when they spec their next truck.