Deep Dive: Western Star 47X

Western Star’s newest vocational chassis, the 47X – introduced last week by Daimler Trucks North America – is more than a scaled down version of the 49X.

While the 49X, introduced a year ago, is better suited to heavier applications like logging, oil field and heavy construction, the 47X is better suited for weight- and length-sensitive applications like concrete mixers, bulk haulers and dump truck setups bound by various bridge laws.

Vocational trucks are among the most complex vehicles anywhere. It’s a real challenge stuffing all sorts of different equipment from cranes to dump boxes to sander/plow setups onto very limited frame space. With the 47X, Western Star pulled through many of the new features introduced on the 49X, while offering vocational operators, including counties and municipal fleets, a chassis that accommodates much of the equipment they use in a lighter-weight, bridge-law-compliant package.

The most obvious difference is the shorter hood – 111.6-inch BBC for the 47X compared with 122-inch BBC for the 49X. With the optional “bridge-law bumper,” the bumper-to-back-of-cab measurement can be further trimmed to 110.8 inches. Wheel-base configurations up to 415 inches are available with the set-forward steer axle, while the set-back axle limits wheel-base to 361 inches.

“There are some 3,142-odd counties in the United States, and each one can have their own bridge-formula,” noted DTNA's Samantha Parlier, vice president of vocational market development, during a pre-release walkaround of the 47X with reporters. “Ten inches matters. Ten inches can be an extra 1,000 pounds [of payload], and it can be it can make the difference between a truck that's illegal to operate, and one that isn't.”

As well as being 10 inches shorter, the 47X is 200 pounds lighter –  spec-for-spec – than the 49X. Several frame rail options are available, including a 9.5-mil rail with the same RBM (resisting bending moment) rating as an 11-mil rail, but it’s about 100 pounds lighter. Standard cast aluminum crossmembers provide additional weight savings without sacrificing strength or durability, DTNA says.

Such frame choices position the 47X well for weight-focused applications such as vocational tractors or mixers.

“We wanted to have the premier mixer truck in the industry, and we know with mixers weight is more of a priority than power,” Parlier said. “So, we focused on building a truck that hits 16,100 pounds for the mixer market.”

New Tools for Upfitters

Designing and assembling vocational trucks is a complex process, so DTNA has pulled much of this challenge into the design process. Engineers work directly with leading truck equipment manufacturers (TEMs) to get the build details right before the truck hits the assembly line, where errors are expensive and time-consuming to correct.

Parlier says it can take up to an hour to drill a single hole in a frame, so DTNA’s engineering teams work directly with the TEMs to get all of the holes pre-punched before the truck is built so they can literally just drop the body onto the truck and bolt it down.

Designers also use a frame-space configurator tool to prevent errors at the manufacturing stage such as placing a hydraulic tank where an outrigger is supposed to go. The configurator fills in the “blank” spaces on the frame, notifying the assemblers that that that space is already spoken for.

“That’s not necessarily a feature of the truck, but it's all automated through the ordering system and the engineering system,” Parlier says. “It was a big investment on our part, and the result is the truck that the bodybuilder needs when it shows up.”

The QuickFit Interface System is another feature pulled from the 49X. It offers ready access to the truck’s electrical architecture using and advanced multiplexed electrical system designed for easy TEM interface, programming and access to power. Connectors are located on the back of the cab, while the electronic control units are stored in the cab in the new dash electronic vault or back-of-cab E-Vault for easy access. Upfitters no longer need to drill into the back of the cab or through the floor. The interface is right at the back of the cab.

Traditionally, upfitters has used the space between the seats to mount driver control interfaces for their various bit of equipment. To keep that space free and to ease installation, DTNA has developed the Flex Panel – a panel that fits into the dashboard B-panel equipped with the appropriate control devices.

The panel would be pre-configured by the TEM and connected to the RP 1226 connectors already in place in the under the panel. The Flex Panel can also be configured with additional gauges, switches, an ELD mount or a RAM Mount prep, depending on customer needs.

“This whole system is designed to be designed to be plug and play, directly into the truck system so that upfit is a breeze,” Parlier says. “Upfitters can have their harnesses, all ready to go, then they can use the CHEC tool to get right into the parameter logic and design logic of the truck.”

Western Star’s CHEC Tool is the interface to the programmable controllers found on X-Series trucks. It enables TEMs and dealers to view and modify electrical configurations, giving them the power to customize inputs and outputs and change parameters within minutes. With the power of QuickFit and CHEC, what was once considered to be complex, expensive or impossible to do can be accomplished more easily and efficiently, DTNA says.

Cab and Body

The X-Series steel-reinforced aluminum cab is said to be 8% lighter while providing 13% more space than competitors, DTNA officials said. The cab structure has steel reinforcement in critical areas such as the backwall header, and the A- and B-pillars. The door hinges are reinforced, and were tested under conditions designed to simulate 15 years of use. The doors are built from galvanized steel and hem-sealed for corrosion resistance. All of the exterior metal brightwork is chrome or stainless steel, not chromed plastic.  

The X-Series cab suspension features vocationally tuned cab isolators designed for optimal cab stability.

X-Series cabs have composite roofs with a lowered, or trenched, center section optimized packaging of over-cab equipment without sacrificing interior headroom or door opening height.

The cab has a one-piece roped-in windshield for faster repair times and optional single or high-visibility three-piece rear windows. X-Series windshields are 28% larger than previous versions, and they use 24-inch wiper blades that cross over the center of the glass, providing a 37% improved windshield wiper zone, according to DTNA.

All X-Series models come standard with a wrap-around dash that provides easy access to the driver command center and B-panel. There’s a multi-function steering wheel, and the new instrument cluster features Daimler’s Driver Command Center.

The truck’s interior also includes upscale appointments such as premium seating, premium insulation for greater quiet and temperature control.  

Three sleeper configurations are available on the 47X: 36-inch trench-style low roof, and 36- or 48-inch mid roof.

The 47X’s hood offers forward visibility of 24.8 feet – an 11-inch improvement over the 49X – while its composite construction and ISO Tech suspension system resists bending and cracking by absorbing and dissipating vibrations from road inputs.

And all Western Star X-Series truck off the full suite of Detroit Assurance safety systems including: active brake assist, adaptive cruise control, side guard assist, tailgate warning, lane departure warning, automatic headlights/wipers and intelligent high beams, brake hold mode, traffic sign display and active speed intervention with Detroit engines, as well as Wabco OnGuard including collision mitigation and adaptive cruise control, optional with Cummins engines.

Powertrain and Drivetrain

The 47X comes standard with the Detroit DD13 Gen 5 engine, which features higher compression ratios and a new swirl piston design to further improve combustion and efficiency. A new feature called ThermoCoasting in the DD13 Gen 5 prevents aftertreatment cool-down while coasting or operating lightly loaded, which keeps the system at its optimum temperature and significantly reduce the need for parked regens.

For weight-sensitive applications, the Cummins L9 and X12 engines are available.

Optional front-engine power take-off (FEPTO) is offered on both Cummins engine offerings and the Detroit DD13 for applications like snowplows. Similarly, rectangular fuel tanks and a raised aftertreatment system mounting are offered with Cummins engines for better clearance for belly plows.

The 47X is also offered with the new DT12-V vocational transmission. It offers three mode applications: rock-free mode, off-road mode, and paver mode.

The 47X is scheduled to go into production in the first quarter of 2022. Customers can expect deliveries sometime later in the year. Despite the current supply chain challenges, Parlier says production for the 47X has been in the planning stages for some time. She doesn’t expect those issue to have a huge impact on deliveries of the truck.

“We are not immune from all that stuff, I'm afraid, but it kind of comes back to one of the benefits of the X Series platform. There's so much shared across the two that we've been able to plan around that,” she says. “We've been planning on the 47X coming into production in the first quarter of 2022 for a long time, and we great supply chain management teams that are doing everything they can to navigate that.”