Forty years ago, Hamm created a milestone in road construction with the first all-wheel drive, all-wheel steering rubber wheeled roller. Now, the roller manufacturer is again presenting a sensation in this sector to the trade.
The new GRW 280 rubber wheeled roller inspires with its revolutionary and future-oriented overall concept. The newly developed series offers excellent compacting quality, plenty of driving comfort, extraordinarily good visibility conditions and the highest of safety standards.
What is so revolutionary about the new rubber wheeled rollers from Hamm? Well, actually everything. You can see it at first glance. It has a completely new cab. In a new position. On a newly designed, asymmetrical frame. The innovations with respect to ballasting, the drive concept and the operating philosophy are not recognisable from the outside. But one thing is soon clear. This machine is full of new features that will make compacting better and more convenient.
The future-oriented concept behind the GRW has already convinced leading international product designers. In early March 2010, they awarded the "new-generation rubber-wheeled roller" with the iF design award 2010 as well as the red dot design award 2010, two of the world's most important design prizes, for its accomplished ergonomics and functionality.
Flexible operating concept
The most important new feature for the operator is the large driver's compartment. Two seats, two steering wheels and two control consoles in the cab used to considerably restrict freedom of movement. Now, there is only one driver's seat. Optionally, it can be moved and pivoted at the side towards the machine's outer edges and along with the console.
Hamm is also taking new approaches in terms of the operating concept. Operation and display elements are positioned on the console and thus always in the driver's field of vision. Also, the speed is no longer controlled by an accelerator pedal in the foot space. The direction and speed are now 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.
Driving comfort par excellence
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.
Always an unobstructed view – also of the wheels
A totally redesigned frame, an innovative arrangement and the glazed design of the cab are the basis for perfect visibility conditions in the new GRW. The cab with integrated ROPS is located in front of the centre of the machine, while the longitudinally installed engine is situated in the rear section of the machine. This ensures an excellent view of all relevant points. The view of the area directly in front of the front axle is also unobstructed. Here, 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. They 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 the rubber wheeled rollers. Hamm utilized this fact in the design of the new GRW and designed the machine frame in symmetry with the wheelsets, i.e. asymmetrically. 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 tyres of the outer wheels. The viewing channels are additionally lit to enable work at night.
Flexible loading
One important quality criterion of rubber wheeled rollers is the ability to be able to swiftly modify the machine's weight. 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. Therefore, the GRW 280 can easily take a total ballast of 10 to 28 tonnes and thus covers all operating options. At the same time, this concept has clearly reduced the loading effort. Incidentally: 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.
Perfect maintenance – definitely
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 dispensed with. Hamm has also made provisions for efficient maintenance. All maintenance points are on the engine's right-hand side. They are illuminated well by the cab lighting and so the drive unit can be inspected even in darkness.
Simple transport
No matter how much the relevant version of the GRW 280 weighs, its machine height is always under 3 m. This not only simplifies transport on a low-bed trailer, but also working under bridges, protrusions or other overhangs.
Technical data of the machines
The new GRW 280 rubber wheeled roller is being launched in the market with various basic weight ratings (10 t, 12 t, 16 t, 20 t, 24 t, 28 t). The machines can accommodate different amounts of ballast depending on the basic weight. The outer dimensions are identical for all variants.
For all types, the "width over tyres" is 1830 mm. The machine has a maximum operating width of 2084 mm.
The GRW 280 is equipped with an environmentally-friendly 4-cylinder engine with a 100 kW output and a common rail injection system. It fulfils the requirements of EU stage III and US-EPA tier III.
