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Make a plane out of a hilly face

They started working in the middle of november: two Cat Scraper 627 G of the F.J. Stetter GmbH delivered by the Zeppelin branch in Ulm. The machines have to move earth in scope of 650 000 cubic metre at an area of about 50 hectare close to the new football stadium of TSG 1899 Hoffenheim. The city of Sinsheim wants to establish industrial real estates for a new industrial area in May next year there. The industrial area will be well connected to the transportation infrastructure because of its closeness to Frankfurt, Stuttgart and Heilbronn by the A6. But until it is as far as that, the two Scrapers have to excavate and reintegrate 100 000 cubic metre of humus.

The yams had not even been harvested when the two Scrapers recently advanced. There had also been leftovers of an asphalted farm track around the area. The company, which is a specialist in land improvement, first had to eliminate both before it was possible to start the exploitation of the area. The company Leonhard Weiss accepted the bid for the exploitation from the city of Sinsheim. Stetter, which is a sub contractor of Leonhard Weiss and responsible for a part of the earthwork, has to plane the hilly area and build it terraced. The use of those two seldom exemplars of the construction equipment is profitable for such works. However, some exertion is necessary because on the one hand there is a pitch of more than 12 per cent, which the Scrapers master with their powerful Cat double-engine. On the other hand there was a thick humus layer in the hutches which had to be excavated. The Cat Scrapers explore the easily solvable topsoil, carry it with their auger in the scraper body, which conceives 15 cubic metres, and transport it with heaps. The ground is stored temporarily for the first time there. “We previously knew that we had to build heaps because the humus had to be redistributed on the flattened area by the Scrapers. Because we know that, we are able to make that strategically advantageous. We attach the heaps over a wide contact area so that we are able to excavate it better and to redistribute it in equally thick coats later. Averaged, one machine embeds between 2 000 and 2 500 cubic metres per day”, explains degreed engineer and foreman Wolfgang Süpple. The maximal depth the Scrapers have to excavate is 10 metre; the maximal level of coating is 16 metre.

The insert of scrapers has to happen in a logical progression. „For the drivers that means they have to pay attention. They have to distribute the material they embed until the end of the track or the area may be not equal. But they have a good grasp of that. They completely identify with the machines and they are proud because they are permitted to move such giant equipment”, says Süpple. An electronic counter, installed into the driving cab, supports the driver during the whole day.

Another challenge for the construction machines are the soil conditions. “The loess-loam-ground is very sensitive to water”, says the foreman. But Stetter wouldn’t be a specialist for ground processing if he wouldn’t find a way. He works with his self developed spreaders from the sister company Stetter Dutzi and soil stabilisers from CAT which are part of his machinery since the beginning of 2008. Previously the ground is purified with them to improve it’s capacity. Therefore a method is executed which the late director of the company, Franz-Josef Stetter, has developed as one of the first in the branch. The binder, which has been adjusted to the ground, is distributed with the help of a special spreader, milled in, mixed and consolidated at the preset area. Stetter becomes an accredited partner for civil engineering companies like Leonhard Weiss. “The most important thing for the efficiency of the machines is the production and compaction of the construction roads”, says Süpple. Only then the Cat Scrapers, which have a net weight of 40 tons, can reach their maximal speed of 60 kilometres per hour. In that case they advance efficient. “With the Scrapers we are able to work significantly more efficient and effective than with other construction machines because we don’t need any dredgers for loading or hutches for transporting or crawlers to level the material. The operating conditions are ideal for a Scraper: there are large areas, easily solvable grounds and routes of transport that are several hundred metres long”, Süpple explains. “We hope that the weather is keeping up and that it won’t rain too much”, Süpple says optimistically. The production schedule is tight in the light of the material to be moved. If it freezes, the company has a technical solution down pat: The ground in the range of excavation is going to be stabilised, the already improved material is going to be adjusted by the Scrapers in a thickness of 40 centimetres and then it is going to be embed into the range of application. Downtimes caused by the weather are reduced to a minimum because of the combination of earthmoving and soil improvement. A professional solution for each construction site. Stetter is well versed in that because the company is successful throughout Europe in the range of soil improvement.


F.J. Stetter GmbH - 73492 Rainau-Buch - Tel. +49 (0)7961 9125-0 - info @stetter-boden .de -  Besuchen Sie uns auf Facebook