Note: only self-propulsed machinery, no cable drawn ploughs etc. are covered on this page!
For other makes see my other page
1912 Siemens 50 hp electric rotary cultivator. This tractor was also made with internal combustion engine, see my Siemens 4 wheel tractors page.
A very early 25 hp electric powered model was shown to the public at the 1914 DLG-show in Hannover.
Early Siemens 4 hp (2 kW) electric rotary cultivator, 1000 of these were manufactured. The cable pole could easily be replaced to other plots. The pole was 6 m high, the cable had a lenght of 25 m, enabling tillage of a 1200 m2 field from each pole position. A trailer behind the tiller was available to transport the pole and the power cables from one field to another.
Where the machinery was not too far from the power supply, it could be directly connected to the electricity wires, which had 120, 210, 380 or 500 Volts AC, or 110, 220, 440 or 500 Volts DC. Siemens-Schuckert supplied special hooks, closing automatically to ensure a good contact.
If the distance between the power supply and the field was so large that too much power was lost by the cable's resistance, high voltage was used, 5000 Volts AC or more. This solution required a transormator to bring down the voltage to i.e. the 1000 Volts AC which the 60 kW cable plough puller needed.
The distance between transformator and puller was limited by the cable length of 300 m. When furrows of 500 m were ploughed, this meant that 30 ha could be ploughed from one connection point. The electric pullers usually had a petrol engine on board, to provide propulsion from one field to another, where no power connections were available between them.
Siemens electric rotary cultivator, model made from ca. 1928. Obviously they had taken over the Grunder cable system by then.
Bungartz U1E with AEG electric motor. In WWII fuel was very scarce in Germany, so Bungartz proceeded where Siemens had stopped experimenting with electric power for tractors. Although this tractor was built after 1945, after the war had ended, petrol engines were used again. The Bungartz U1E was shown on a German DLG-show, I have never seen any electrical powered garden tractors at all. The cable was mechanically wound up on the tractor.
Here the Bungartz U1E is shown in operation. It had two speeds, of 1.3 and 5 km/h. The motor power was 5 kW or 6,8 DIN hp.
This Bungartz diagram shows that with only 4 power plug connections and a 100 m long cable on the tractor, a 20 hectare plot could be tilled. If another 100 m extension cable was used, only 2 connections were needed for the same 20 hectare. I wonder how many round plots exist in Germany?