Kemroc chain cutter at work in Austria laying water pipes in the high AlpsPublished 7/3 at 16:47
A Kemroc EK 150_800 chain cutter mounted on a 50t excavator was used to renovate and extend a ski area in Styria, Austria. The work required a 700m trench to be excavated in hard limestone at an altitude of 1,700m to supply water to new snow cannons. Thanks to the productivity and low transport costs for excavated and fill material resulting from the use of a grinding attachment, the contracting company, Karl Pitzer GmbH, succeeded in completing this ambitious project in time and within budget.
The Loser Ski Resort is located on the 1,803m high Loser Mountain near Altaussee in Styria, Austria. To secure the future of winter sports in the area, the locale has invested €4.5M making improvements, renovating some of the existing ski slopes, building new ski slopes, and extending the range of the artificial snow systems with the installation of ten new snow cannons. As part of the renovations, the summer of 2018 saw contractor Karl Pitzer GmbH start work with a Kemroc chain cutter excavating a 500m pipeline trench to connect new snow cannons to a 70,000m³ storage reservoir. The contractor is well-known as a civil engineering company, and is based in Schladming in Styria, Austria. The family business specialises in technically difficult projects such as the installation of artificial snow systems.
At the start of the project, Pitzner engineers excavated the pipeline trenches containing a mixture of solid limestone and hard rock boulders. In 2017, at the start of the two year project, the trench was being excavated using drill and blast and hydraulic excavator with a hammer attachment. At this time, Pitzer had its first contact with Wimmer Felstechnik, Kemroc’s Austrian agent, followed up by a visit to the MAWEV construction show and to the Kemroc stand. At the show, Pitzner had the opportunity to see the chain cutter at first hand, and discuss excavating using the attachment. After further discussions, it was decided to try the Kemroc EK 150_800 chain cutter on one of Pitzer’s 50t excavators at the Loser Ski Resort project.
Usually, trenching in solid rock containing hard rock boulders is still carried out using a combination of the traditional methods of drill and blast and hydraulic excavator with hammer attachment. This excavation method is slow, very hard on the excavator and operator, and creates a trench which is always larger than required with a large volume of large particle size excavated material. In comparison, the EK (Erkator) range of chain cutters from Kemroc can sometimes be quicker, more economical and, in ideal conditions, easier on the excavator and less tiring for the operator. The chain cutter has a patented chain fitted with tungsten carbide round attack picks, and excavates the material located between the two external cutter drums. The attachment excavates a trench with vertical, parallel sides to the exact dimensions required as there is no need to excavate more material than necessary, with the material excavated also having a grain size small enough for use as back fill, this providing savings in the cost of transport and back fill material.
Pitzer experienced all these advantages at the Loser Ski Resort. Out of a total length of 700m, 500m of the 1.5m deep trench was excavated in a period of about four weeks in the summer of 2018. While excavating with a hydraulic breaker, the operator was forced to start with a much greater width at the top of the trench in order to achieve the required width of 800mm at the bottom.
“Importantly, when excavating in solid rock the chain cutter gave us two major benefits: firstly, the trench profile was much smaller and secondly, the material taken out of the trench was re-usable,” so explained Pitzer’s excavator operator. Company director Karl Pitzer confirmed this, “Compared to using a hydraulic hammer and blasting, our experience has shown that the use of a chain cutter in solid rock has been ideal: we are keeping the size of the trench to a minimum while excavating material that can be put straight back into the trench. In situations such as these, trenching at altitude in the mountains, transportation of large volumes of material represents a very important cost factor and they must be kept to a minimum.”