The range of soil stabilizers offered by Wirtgen GmbH was expanded in 2004 to include not only self-propelled machines but also two tractor-towed models. Owing to the great success achieved in European markets, Wirtgen has now enhanced the two tractor-towed models further by launching a second machine generation: the WS 220 and WS 250 offer new technical features which make both operation and maintenance of these units even more efficient.

Broad range of applications, mixing results of high quality

The WS 220 and WS 250 are used as compact attachment units, towed by a tractor, for efficient soil stabilization. Both units have a working depth of 500 mm. The WS 220 offers a working width of 2,150 mm while the larger machine model, the WS 250, has a working width of 2,500 mm. Their scope of applications covers both soil improvement and soil consolidation projects.

The tractor-towed stabilizers can be relied on to convert heavy, coarse-grained or sandy subgrade material into soil that is highly suitable for placing and compacting. If too coarse, the material to be mixed is crushed in the mixing chamber by the milling rotor. This type of soil improvement – enhanced further by mixing in suitable binding agents, such as lime – pays off in all earthmoving operations for the construction of dams or embankments, backfilling or site haulage roads. The bearing capacity of large surfaces is thus improved quickly and reliably with only little effort.

In soil consolidation, binding agents like cement are additionally mixed in by the tractor-towed stabilizers to produce soils of permanently high bearing capacity that are capable of withstanding traffic loads and weather influences in the long term. Areas stabilized by this method are suitable for the construction of parking lots, roads, sports grounds, track beds, harbour docks, airfields and industrial facilities.

Milling and mixing rotor: power and optimized mixing chamber geometry

In terms of efficiency, Wirtgen tractor-towed stabilizers have impressed for many years owing to their tried and tested, mechanically driven milling and mixing rotor: mechanical belt drives left and right guarantee high efficiency and optimum utilization of the tractor’s power. Hallmarks of the dual drive system are low maintenance requirements and extremely low wear and tear. In addition, the eccentric milling drum gearbox makes sure that the pulley housing is above the ground at all times.

Material flow in the mixing chamber has been optimized further by creating a modified design geometry that enables the rear opening to increase in size dynamically, resulting in a higher throughput of material thanks to the adjusted mixing chamber design. The new design has a positive effect also on fuel consumption rates.

New features: stone guard and adjustable levelling blade

Two new features have been developed for the tractor-towed stabilizers: to produce an even, smooth and continuous surface texture regardless of the working depth, the new attachment units are fitted with a mechanically adjustable levelling blade in the bottom part of the drum plate. The levelling blade has a setting angle of 60 to 80 degrees. It can thus be set to a steep angle when working at the maximum milling depth of 500 mm with the drum plate adjusted to a flat angle. At lower working depths of 200 mm, for example, with the drum plate adjusted to a steep angle, the levelling blade is simply set to an extremely flat angle.
An adjustable stone guard is installed at the front of the tractor-towed stabilizers: it protects against stone chipping and reduces the development of dust when working with pre-spread binding agents. The stone guard can be adapted to prevailing conditions individually and is adjustable in height hydraulically. It is raised when working at large working depths, and is lowered when working at low working depths.

Digital milling depth indicator right in the driver’s cab

The optionally available milling depth indicator is a convenient and practical assistant to the machine operator. The display allows intuitive operation and can be attached in the immediate reach of the driver inside the tractor’s cab. This feature permits the driver to work in an ergonomic body posture as he will not have to keep turning around in order to monitor the milling depth. Precise measuring of the working depth is effected via ultrasonic sensors mounted to the left and right of the tractor-towed stabilizer. The working depth is set manually via the tractor’s rear power lift and is additionally indicated on a scale at the side plates of the attachment unit.

Quick replacement of cutting tools with special tool extractor and HT11

Wirtgen is now offering an optional pneumatic cutting tool extractor for the tractor-towed stabilizers which is simply connected to the tractor’s dual-circuit compressed air system. The convenient tool extractor reduces downtimes of the machine for tool replacement by more than fifty percent. If the customer chooses the optionally available HT11 quick-change toolholder system in lieu of the standard HT9 system with fully welded toolholders, the time needed for maintenance is reduced even further: worn upper toolholder parts can be replaced immediately on the construction site.

Broad range of suitable tractors, attached in no time at all

Various tractor types are suitable for use with the tractor-towed stabilizers. In terms of performance, a tractor with state-of-the-art, infinitely variable transmission is required to ensure the efficient operation of the tractor-towed units from Wirtgen. It needs to have a minimum engine power of 150 kW for use with the WS 220, and 180 kW for use with the WS 250. The WS 220 or WS 250 is mounted to the tractor simply and with just a few flicks of the wrist via the tractor’s lower and top links and the standardized category-3 or category-4 three-point hitch. A specially designed hydraulic top link with high tensile and compressive strengths is available for this purpose as an equipment option.

Wirtgen GmbH
Claudia Fernus
Reinhard-Wirtgen-Strasse 2
53578 Windhagen
Germany

Phone: +49 2645 / 131-744
Fax: +49 2645 / 131-499
e-Mail: presse@wirtgen.de