WR 250: the powerhouse of the Wirtgen cold recyclers and soil stabilizers shines in acid test

The factory expansion of Hamm AG in the summer of 2012 was a real acid test for the machines of Wirtgen and Hamm; the dimensions were tremendous. The plan was to prepare a 150,000 m² large area, and move around 350,000 m³ of earth in the process – in only three months. Hamm had contracted the Max Bögl Group as the general contractor for the measure. The focus of the activity was on the brand new bauma specimens, the Wirtgen cold recycler and soil stabilizer WR 250 and the Hamm H 13i earthmoving compactor with plate compactor attachment. The result: the innovations were convincing with respect to performance, handling and reliability.

Wirtgen WR 250 masters heavy soil effortlessly

The first challenge: the existing gradient had to be smoothed out and an even surface created on the grounds behind the previous factory. The Wirtgen WR 250 was used while excavators removed masses of earth in the upper half to depths of up to 12 m and placed around 50 percent of the material onto the lower lying area. The powerhouse is the highest performance machine of the new WR generation and is specially designed for the stabilizing of heavy and boggy areas. Cement was scattered in advance as a binding agent before the soil stabilizer came into action. Thanks to its high engine performance and optimal traction, the WR 250 was subsequently able to work its way effortlessly through the heavy soil, which it homogeneously mixed at a depth of exactly 40 cm. "Despite the high level of material throughput totaling 725,000 m² of soil, the wear of the milling drum and of the drum housing was extremely minor, which can be traced back to the innovative drum design with the feature, among others, of the open corner rings," says Christoph Menzenbach, application technician at Wirtgen.

Thanks to the possibility to control the cutting rotational speed from the cab, it was no problem for the machine operator to react to the dramatically changing soil conditions and to flexibly adjust the corresponding cutting drum rotational speed to the in some cases stubborn, loamy and then sometimes loose soil. In combination with the cutting drum design tailored to the high performance of the WR 250, an exceptional mixing quality with a forward speed that is quite high for the soil conditions of 16 m per minute was achieved.

High daily performances and maximum operating comfort

Using the sensitive multifunction joystick on the right armrest, the machine operator was able to simply and comfortably control all important base functions. Automated processes, such as automatic lowering and raising of the milling and mixing rotor, the ergonomically designed workplace and the innovative reverse assistant also provide enormous relief. "The new Wirtgen WR 250 convinced us in every respect, starting from the perfect panorama view of the machine and the construction site, the intuitive operation and ending in the perfect mixing result. The high daily performances of up to 15,000 m² were impressive“, Gunnar Bellmann, site manager of Max Bögl, spoke enthusiastically of the performance capacity of the powerhouse

Hamm rollers reliably compress soil

Behind the soil stabilizer, the H 20i P with padfoot drum first compressed the prepared soil. This was followed by two compactors (H 18i and H 20i) with smooth drums. The final sealing of the new level was carried out with the rubber-wheeled roller GRW 280 in the new version with "i" technology before it was covered with a 20 cm thick frost protection layer. This was compressed with the new H 13i compactor with the plate compactor attachment, one of the three "new models" from the H series, which celebrated its official premier at bauma 2013.

Factory expansion in Hamm: Wirtgen Group machines completely convincing

Besides the area in which machines and buildings will find their place in the future, Hamm also enlarged the testing grounds to 30,000 m² with the construction measure. A SUPER 1900-2 from Vögele finally ensured the installation of several asphalt areas.

Also thanks to the good cooperation of the Wirtgen Group machines, the team from Max Bögl was able to complete the construction work on schedule in only five months. With the acid test, the Wirtgen WR 250 and the Hamm H 13i successfully proved their reliability in soil stabilization and compaction. Both devices are among the 29 innovations that the Wirtgen Group will present at bauma 2013.