The Hamm GRW 280 pneumatic (rubber-tired) roller, with an operating weight between 10 and 30 short tons, provides numerous innovations.
In the operator’s workplace, instead of the previous setup with two seats, the new GRW offers one comfortable, adjustable seat and thus maximum freedom of movement.
For the first time ever, viewing channels in the frame structure offer a view of the edges and the tires of the outer wheels. What’s more, a novel suspension of the front wheels allows for an uninterrupted view towards the front.
Hamm’s new GRW 280 rubber wheeled roller platform offers excellent compacting quality, plenty of driving comfort, extraordinarily good visibility conditions, and the highest of safety standards. For example, the new GRW 280’s operator’s platform rests in a new position, on a newly designed, asymmetrical frame.
Innovations with respect to ballasting, drive concept and operating philosophy are not visible from the exterior, but their effects are evident as they make compacting better and more convenient.
Now a single driver’s seat - which optionally can be moved and pivoted at the side towards the machine’s outer edges and along with the console - has replaced two seats, two steering wheels and two control consoles in older models, which could restrict freedom of movement. Operation and display elements are positioned on the console, and thus always are in the driver’s field of vision. Also, the speed is no longer controlled by an accelerator pedal in the foot space; now they’re controlled by joysticks, which signifies a considerable boost in convenience for the driver. In total, the new operating concept corresponds to that of a tandem roller. Thus, cost-effectiveness is increased because in the future, operators can switch flexibly between roller types without any adaptation time.
Higher Speeds For Transport, Compaction
A hydrostatic rear-axle drive for the GRW 280 will allow for higher speeds during transport and compaction. To match it, the newly conceived steered axle at the front with disk brakes ensures the necessary braking force and thus considerable safety when braking suddenly, even with maximum load. In total, sensitive control of the rear axle and an extraordinarily good view of the site and the wheels’ edges enable high compaction quality.
The operator’s platform - with enveloping ROPS - is located in front of the center of the machine, while the longitudinally installed engine is situated in the rear of the machine. This ensures an excellent view of all relevant points. The view of the area directly in front of the front axle also is unobstructed. There, hydraulic cylinders for level compensation of the front suspension used to protrude out of the frame into the driver’s field of vision. They have been replaced with two swing arms between the front pairs of wheels, which require very little space and are not visible to the driver. The track offset between the front and rear wheelsets is one of the basic features of pneumatic rollers. Hamm utilized this fact in the design of the new GRW and designed the machine frame in symmetry with the wheelsets. This intelligent design offers one crucial advantage because, for the first time ever, the driver can see the wheels on all outer sides. Moreover, viewing channels in the frame structure offer a view of the tires of the outer wheels. These viewing channels are illuminated to ease work at night.
Flexible Weight Loading
Rubber-tired rollers need to be able to have their weight modified swiftly and easily. To this end the GRW 280 offers large ballast spaces between the wheelsets, and a serrated frame that is open in the downward direction. It can be filled with steel or concrete using a forklift truck. The GRW 280 can easily be ballasted from 10 to 30 tons, covering all operating options. At the same time, this concept has clearly reduced the loading effort. And regardless of how much ballast a GRW 280 carries, thanks to the intelligent ballasting system, the distribution of weight to the front and rear axles always remains constant.
The new GRW 280 rubber wheeled roller is being launched in the market with various basic weight ratings (10 t, 15 t, 20 t, 25 t, 30 t). The machines can accommodate different amounts of ballast depending on the basic weight. The outer dimensions are identical for all variants.
The generously dimensioned brake system ensures the higher-than-average safety standard during driving. When the machine is idle, the access steps to the cab afford additional safety. They are integrated in the outer contour and can be folded out. Thus, they offer convenient and safe access to the maintenance platform next to the engine. In this position, they lie on the outer contour, but constitute a visual interference contour.
As a result, after completing maintenance work, the operator is reminded to swivel the access steps back into position. At the same time, the maintenance accesses, which would otherwise have to be carried along separately, are eliminated.
Hamm also has made provisions for efficient maintenance, as all maintenance points are on the engine’s right-hand side. No matter how much the version of the GRW 280 weighs, its machine height is always under 10 ft. This not only simplifies transport on a low-bed trailer, but also working under bridges, protrusions or other overhangs. The GRW 280 is equipped with an environmentallyfriendly 4-cylinder engine with a 134-hp output, and a common rail injection system. It fulfils the requirements
