Our master students recently participated in a 4-day excursion in the Vogtland-region, and learned many different aspects of forestry and wood products through visits in local forest areas and companies. This blog post series, written by the participating students themselves, highlight some of these encounters!
The last point of our four-day excursion to Saxon Vogtland was the Sawmill “Schauer” in the municipality of Werda. It is the fourth mill in the so called “Valley of the ten mills” at the stream “Görnitzbach”. First credentials which witness the existence of a mill at this location date back until the year 1224. In 1524 the mill was rebuilt into a sawmill, driven by a waterwheel. Since 1877 it is family-owned by the “Schauer’s” and in 1933, they switched to an electrical powered drive. Although it was not expropriated in the GDR (former East Germany), it stood still from 1960–1970. After the reunification (of the two Germanies), a new era began with the purchase of a new band saw in 1992. Today it is the only one of its kind in the entire region. The cost of this band saw is about 1 million euros, the total cost of this sawmill amounted to about 3 million euros.
FOTO: Mr. Schauer senior (left), proudly presented his sawmill and guided us through the production facilities. Nowadays, the family business is run by his son (right).
Most of the processed timber is recently harvested round wood of the surrounding Vogtland region, from coniferous as well as deciduous trees. Exceptions are Douglas fir which comes from Baden-Württemberg and tropical timber, which is processed as contract work for the local musical instrument craftsmanship, to build for example violins and guitars as well as grand pianos. In one year the saw can cut up to 3,500 cubic meters of wood, with diameters up to 1.20 meters thick and lengths up to 12 meters long. In one minute it can cut between 25 and 60 meters of wood. A special feature of the band saw is that the cutting thickness can be changed at any time. The thinnest possible thickness for cutting would be incredible 1 mm.
FOTO: For demonstration purposes, Mr. Schauer senior stopped the production to cut a 2mm thin piece of wood.
The 1.2 to 1.3 millimeter thin band saw blade runs over two pulleys (one meter in diameter each) with a tension of 16 to 18 tons at approximately 700 revolutions per minute. Between the pulleys are 2 meters of free running band saw blade, including the cutting area. The saw teeth are made of Stellite, a special Canadian hard alloy with a high cobalt content that makes them extremely sharp. This is important for cutting long-fibred species such as hemlock, poplar and linden that would otherwise end up as wood shavings. As mentioned above, the saw can cut soft as well as hardwood. The band saw technology thus achieves a high efficiency of 73% timber output.
Mr. Schauer senior says that man is the biggest enemy of the sawmill industry. The Reason for this statement are the many different objects found in the wood. Among other nails, stones and cramp irons as well as bullets and splinters some of which are silent witnesses of the world wars or even older. Often these objects are invisible from the outside because they have been completely overgrown by the wood and their detection with a metal detector would not be profitable. As soon as the saw blade encounters such an object at its high speed and tension, the entire saw blade can be torn in the middle. Since a saw blade costs about 800 euros, they try to maintain it as good as possible, for example by using it for only 6 hours and then letting it rest for another 12–24 hours. Besides this the saw blade is reground and sharpened regularly. This takes place in the sharpening chamber, that Mr. Schauer senior calls the heart of his sawmill. A well-maintained saw blade lasts about a year.
After all the technical specification that Mr. Schauer gave to us, he invited us to the administrative office of the Sawmill, there they gave us a warm farewell before it started raining!
For me, coming from Peru, it was a familiar view this type of sawmill, as in the tropical rainforest many of the sawmill use these big saw band to log the big timber trees from the natural forest. The main difference was the ubication of the sawmill. In Peru, many of the sawmill on the rainforest are located on the riverbed, as the transportation of logs is done by the river, thus reducing transport cost, as otherwise some wood would be unprofitable to transport.
All in all it was a refreshing experience, and let me see that the processes are very similar in Germany and in Peru, being the woody species the main difference. Also the security measure are much higher in Germany. Luckily we do not have the problem of hidden objects in timber!
By: Hendrik & Jorge