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    [Job Story] Cat Equipment Extracts Jurassic Limestone Blocks in Germany

    Together they have more than a hundred years of professional experience in the extraction and processing of raw materials: Günter Gallus, Marcus Hausner and Michael Sigl from VeroStone in Eichstätt. In 2020, they have been long-serving executives from their employer, the facade specialist Sto SE & Co. KGaA, acquired the natural stone company as part of a management buyout.

    Der Naturstein für die Seeresidenz in St. Petersburg von Gazprom kommt aus dem Altmühltal. Foto: VeroStone

    All 74 employees were taken over – they will continue the production of limestone, shell limestone and sandstone, which has been running smoothly for many years. The new management of VeroStone wants to maintain the course. As far as the construction machinery technology used is concerned, however, a different philosophy is being pursued: Young Cat technology is to take over the raw material mining. A Cat 986K wheel loader has a key role in this.

    Many of the construction machines used up to that point bore witness to their longevity – 20,000 hours of hours on the meter and more were not uncommon. A good example of this: An old Cat 988B wheel loader. Today, it would still be ready for use at any time. But in the future, it will be kept by the company as a stand-by device at best. The Cat 986K, 980M and 966M wheel loaders, the Cat 323CLN and 323FL tracked excavators 323CLN and 323FL, and the Cat 735C and 740C dumpers. They operate at different levels to have access to the different limestone strata that are currently in demand.

    During the winter months of January and February, preparations are underway at the quarries VeroStone quarries to prepare the production sites for quarrying: the roadways and ramps are repaired and brought up to scratch. The construction machines, especially the track excavators, remove the five to six-metre high overburden and expose the layers of Jurassic limestone that are then extracted during the rest of the year. 150 million years of earth history have not remained without traces in the Altmühl Valley: fossils such as ammonites are proof that a sea once covered the earth.
    covered the earth. Deposits were created that formed the Jura marble or, more accurately, the Jura limestone. In the past, it was quarried by hand. Then the blocks were then taken out with a crane and a crawler loader.

    Today it’s a combination of drilling and ripping. The Cat 323FL and 323CLN crawler excavators act as drill rigs, remotely creating vertical holes in the rock strata. Hydraulic splitters are inserted into these holes, which use a pressure of around 300 bar, they detach the mighty natural stone from the solid bond – deep cracks appear. That’s when more Cat technology comes into play. The Cat wheel loader 986K pushes its ripper tooth under the block and breaks it out. By means of a great force, layer after layer and block after block are separated. Their size depends on the natural fissures and crevices as well as layer thicknesses.

    The natural stone for Gazprom’s lake residence in St. Petersburg comes from the Altmühl Valley. Photo: VeroStone

    However, loosening the blocks is not the end of the story – the block is usually usually measures around 3.00 x 1.50 x 1.00 metres. This can add up to a load of 13 tonnes and more. Such a heavy block has to be transported and loaded. For this task, the driver exchanges the ripper for forks. With these he heaves the mighty block onto a Cat 735C dumper, which transports the Jura marble to the processing plant. In the meantime, the quarry has reached a depth of 29 metres. The deposit is characterised by 26 layers, which are quarried in different terraces. The layers are usually separated by clay layers and vary in thickness and colour between and vary in thickness and colour between yellow and grey.

    “Each layer has its own colour characteristics, structure and special technical and geological property, which, once processed, are suitable for interior or exterior use as façade, floor and wall panels, window sills and stair treads”, explains Günter Gallus, managing partner.

    These have international customers, such as a district in Edinburgh, Scotland, or Gazprom’s new seaside residence in St. Petersburg. Gazprom. But the products can also be found in the Altmühltal itself, as on the natural stone façade of the natural stone façade of the Eichstätt climbing centre.

    For several decades, VeroStone quarries have been using Cat construction machinery.

    “Caterpillar is more or less our house and home brand. We have accompanied the development of machine technology, for example from the F to the K and M series,” says Marcus Hausner, Managing Partner.

    Consumption and a lower CO2 balance were the reasons for the conversion of the fleet in the dismantling process – these are aspects that are gaining in importance in the course of sustainability. gaining in importance.

    “The new machines have become much more efficient and faster,” says Michael Sigl, authorised signatory and operations manager. Here, too, the Cat 988B serves as a reference: 50 litres of fuel per hour were once the norm at peak times – this compares to  consumption of just under half that of the 986K.

    “When we work in the overburden, we need a heavy piece of equipment that also has a correspondingly high speed,” adds Michael Sigl.

    The tyres and their tread also deserve tyres and their tread deserve special protection. So extra chains were fitted, to reduce the heavy wear. After all, a lot of weight presses on the small contact surfaces between the rubber and the ground, and this is where the entire propulsive force of the wheel loader is generated when it loads blocks and then drives them to the warehouse. Such equipment details have proven to be useful in practice. They must be just as well considered as the right machine size.

    Adds up to a load of 13 tonnes and more: Cat wheel loader hoists the mighty block onto a Cat 735C dumper, which transports the Jura marble to the for further processing.

    With Zeppelin new machine salesman Wolfgang Wagner from the Erlangen branch the various weight classes that could have been considered were compared. For example, the purchase of a 35-tonne and a 53-tonne loader was considered. were considered. But most of the arguments were in favour of the 46-tonne Cat 986K: a powerful machine that is also powerful machine that is at the same time still suitably manoeuvrable. “A key requirement was to be able to continue using the old LOC-matic attachments,” explains Wolfgang Wagner. This could be assured for the Cat 986K, because in this case hardly anything had to be changed in the implement mounting. The attachments are compatible with each other and, due to their quality, can be used by other Cat wheel loaders for another machine lifetime. In addition to a ripper tooth, the Cat 986K works with a fork to a fork to transport the blocks to the storage yard. In addition, there is a bucket, to take overloading tasks in the quarry. To ensure that the tools can be changed quickly, the construction machine was equipped with a quick coupler.

    The natural stone for Gazprom’s lake residence in St. Petersburg comes from the Altmühltal. Photo: VeroStone

    So far, no 46-tonne loaders have been used in the region for quarrying Jura marble in the Altmühl Valley. Tonne loaders in the region, only smaller or larger loaders, although a Cat 986K would also be suitable for other applications. But I am convinced that the 46-tonne loader can definitely prove its potential here,” says Wolfgang Wagner.
    Günter Gallus, Marcus Hausner and Michael Sigl also hope so: “We want to increase our performance in the long term and at the same time improve the CO2 balance of our products. At the same time, our driver should be happy with it.” The fact that investments in new work equipment contribute to a boost in motivation can be seen in seemingly small things. “The driver even changes his shoes before entering the cabin. He takes great care of his equipment and looks after it.”, his bosses are pleased. But he also has to keep an eye on his load. Because what he transports as a block can be worth up to 2,500 euros.

    Chiara De Paoli
    Chiara De Paoli
    Editor at HeavyQuip Magazine and International Operations Manager for V22 Media