The Komatsu HD325-8 and HD405-8 rigid-frame haulers, replacing Dash-7 models, have respective payload capacities of 40.3 and 44.1 tons and approximate maximum gross vehicle weights of 156,000 and 171,000 pounds. The trucks use a 514-horsepower (net) Tier 4-Final Komatsu engine that delivers estimated fuel savings as high as 9 percent for the HD-325-8 and 6 percent for the HD405-8, compared with Dash-7 models.
Exhaust-emissions controls include a hydraulically actuated exhaust-gas-recirculation system, variable-geometry turbocharger, selective-catalytic-reduction system, and a Komatsu diesel particulate filter, which, says the company, features more than 98 percent passive regeneration, causing no interference with machine operation and requiring no action from the operator. Engine modes (Power and Economy) allow the operator to optimize performance, says Komatsu, and an auto-idle shutdown can reduce idle time and further save fuel, says the company.
Standard equipment includes the Komatsu traction-control system that automatically applies independent brake assemblies for optimum traction as ground conditions vary. The system operates without differential lock-up, says Komatsu, and “steering performance is not compromised.” Retarding capability matches Dash-7 performance, says Komatsu, and the HD405-8 features larger standard tires, with 21.00 R33 tires replacing the previously used18.00 R33 tires.
Other new features include a fast-fill fuel system and redesigned cab with 7-inch LCD display, rearview monitor, heated/ventilated air-suspension seat, auxiliary jack and two 12-volt ports, and a sound rating of 78 dB(A). The company’s Komtrax telematics system and monitor provide key machine metrics, says the company, including particulate-filter status and fuel consumption. Performance information can be collected and sorted by operator ID.
- New angled front access stairs with handrails as standard for both sides of the machine
- Tight turning radius with MacPherson strut front suspension
- Hydropneumatic suspension system
- Komatsu Advanced Transmission with Optimum Modulation Control System (K-ATOMiCS) that adjusts shifting performance to match demand, resulting, says Komatsu, in a more comfortable ride and reduced material spillage
- Automatic Retard Speed Control (ARSC) system that automatically maintains a selected downhill travel speed (rather than engine RPM) appropriate for the grade
- Enhanced Komatsu integrated payload meter (PLM) data available on the machine monitor and remotely via the web
- New ground-level accessible battery box for easy maintenance
Standard equipment included Komatsu’s traction-control system, which automatically applies independent brake assemblies for optimum traction in varied ground conditions. Both models use a redesigned cab that features a 7-inch LCD color display, rearview monitor, fast-fill fuel system, heated/ventilated air-suspension seat, and sound rating of 8 dB(A).