File:PSM V24 D767 Siemens and Halske electric train at the 1881 paris exposition.jpg

English: Siemens and Halske electric locomotive at the 1881 Paris exposition. This first electric mining locomotive was the second electric locomotive altogether. She ran 45 years from 1882 until 1927, and was named Dorothea. The drawing is made after a company photography of 1882.

In June 1878 Werner von Siemens drafted an electric locomotive with a gauge of 520 mm (1ft 8in). She was scheduled for an underground brown coal mine near Senftenberg, but the mine owner refused to accept her. Siemens seized this opportunity and presented the rejected locomotive as tractor for a little passenger train at Berlin Trades Exposition 1879. More than 90,000 passengers were transported and thus the locomotive proved to be reliable. In 1882 Siemens offered another locomotive, the later Dorothea, based upon the passenger locomotive of 1879 to the Royal Saxon Coal Works, which operated a coal mine in Saxon Zauckerode near Dresden.

This locomotive had two drive axles. The driver rode with one leg on each side of the locomotive and placed his feet on footings at about the same level as the axles. He had to look over the engine for driving. For collecting the electricity the locomotive dragged a trolley behind her. This small contact carriage ran with horizontally arranged wheels on an inverted overhead mounted Ʇ-rail. With a contact slide for avoiding electric sparks was experimented as well, but in the long run the trolley performed better despite its shortcomings. Brake and controller were at one end; at the other end were only crank handles driving these devices by chains.

The locomotive was driven by a 4.5 KW (6 HP) motor. It permitted a tractive effort of 1.7 KN and made 700 revolutions per minute. Maximum current consumption was 70 Ampere. The operating voltage at the trolleys was between 80 and 90 Volt. The locomotive weighed 1550 kg (3417 lbs.).

From 1883 until 1902 Siemens built 52 similar locomotives for other mines. Their tractive efforts were 1.48 KN. They were powered with a 7.4 KW (10 HP) motor and were a little lighter, 1500 kg (3307 lbs.). The tractive effort was higher, 2.0 KN. One of those bought the Royal Saxon Coal Works in 1891. When this second locomotive could fill a gap, the first locomotive from 1882 was rebuilt following the example of the 1883 model. The power of the longitudinally mounted motor was now taken off from its pinion by a bevel gear shaft, which transmitted the power to the axles.Very few parts of the 1882 model survived the refurbishment of 1892. The locomotive was decommissioned in 1927, when the shaft and its cross cut were closed. She was given back to Siemens in Berlin. She suffered no damage by the bombing during WW II and was moved to Munich in 1954.