When the new Bomag BW161AD-4 HF tandem vibratory roller was released some months ago, it reflected a fresh new design, featuring slanted drum-support legs, high-curb clearance, and a clear view to drum surfaces and the sprinkler systems. Now, that same basic design efficiency has been applied to the new and larger BW190AD-4HF, which is fitted with 79-inch-wide drums, versus the BW161AD-4 HF's 66-inch drums. The new model, with an operating weight of 26,015 pounds, uses a 131-hp, water-cooled Deutz diesel, which is tucked beneath the operator's station.
With the engine thus positioned, Bomag had the design latitude to shape the water tank (rear frame) and the radiator cover (front frame) to enhance the view to drum surfaces, drum edges and spray bars. Because the open design of the front and rear frames allows an unrestricted view of both drums and the wetting systems, says Bomag, the operator can quickly spot potential asphalt pickup.
At the heart of the BW190AD-4HF is a vibratory system that provides dual amplitudes and dual frequencies. Centrifugal force is 28,800 pounds in its low-amplitude/high-frequency (3,600 vpm) setting, and 40,950 pounds in its high-amplitude/low-frequency (2,880 vpm) setting. Independent drum-vibration control, says Bomag, coupled with dual amplitude/dual frequency capability, allows the roller to take on a wide range of lift thickness in varied applications—from granular bases to Superpave.
The BW190AD-4 HF's operator station reflects an intuitive design that simplifies control of all roller functions. Dual steering-wheel positions provide optimum visibility on either side of the machine, says the company, and a sliding and swiveling (180 degrees) seat gives easy access to both positions. Travel and vibration controls are integrated, placing critical controls comfortably within the operator's hand. The center-point articulated steering system features a 6.7-inch crab-steer offset (left and right), which increases rolling width and helps prevent curb contact when rolling in and out of turns.
On the service side of the new roller, swing-out panels on the engine compartment provide wide-open access to routine maintenance items and eliminate the hassle of having to raise the complete operator's station to perform these relatively simple chores, says Bomag. The water system features easy-to-clean, pop-out spray nozzles, as well as a six-position, spray-interval timing system that conserves water. A second water pump—a backup—is capable of handling the pressurized-water requirements of the machine. In addition, the spring-loaded scraper bars are easily lifted or removed for cleaning.
As an option, the new model can be equipped with Bomag's Asphalt Manager system which, says the company, automatically measures and controls the compaction performance of the roller to ensure optimum results. The system also can be equipped with a printer if required.