Every two years a meeting of steam engines and tractors takes place at Kiekeberg. I am always fascinated to see the old technology of steam engines in operation. Matching the agricultural machinery at the meeting, one of the steam engines was used to drive a threshing machine. To my astonishment those threshing machines were still used in Germany until the beginning of the 70s!
The steam engine is lovingly maintained. The oil level is checked again before starting and refilled if necessary. The machine should be used twice a day and drive the threshing machine. The picture on the right shows a sight glass for the water level between the two machine operators.
It is extremely important that the water level is always kept at a special level in order to prevent the boiler ceiling from falling dry and thus becoming glow-through. Two taps are installed on the left side of the boiler, which can also be used to check the water level. Should the sight glass ever break, steam must come from the upper of the two taps and from the lower water. The sign between the two taps with the inscription N‑W shows the standard water level.
By the way, the boiler had to be replaced in 1996, because the TÜV had only approved the old boiler of an operating pressure of 3 bar. That would have been enough to drive only the flywheel. For the drive of machines a pressure of up to 10 bar is needed!
Then finally the second threshing operation began. The machines were coupled and the threshing machine was put into operation. You can see that even with the steam engine driving a threshing machine it was a hard working day standing on the threshing carriage.
Many thanks to Alfred Scheurer (one of the operators), who explained the machine to me and my son in detail.