The 1941 Class ET 125, later adjusted series 276.0 (DR) or 477 (DBAG), was an electric railcar which traversed the DC-powered S-Bahn in Berlin during 1934/35. It was built in 1936 and 1938. The cars, which were popularly known as banker trains, were rebuilt after World War II and the series ET / EB 166 adapted. Among other things, they lost the more powerful 1949/50 traction motors. From the 1970s, they were included in the modernization program and in series 277 rebuilt (after 1991 477/877), they were used on Berlin's S-Bahn network until 2003.

DR Class 125
ET 166 047 (adapted from ET 125) in Erkner
ManufacturerO&K, Dessauer Waggonfabrik, Wegmann – Wagenkästen; AEG, SSW – elektrischer Teil
Constructed1934-1935
Scrapped2003
Number built18 power cars,
18 trailer cars
Specifications
Train length36.2 m (118 ft 9 in)
Maximum speed90 km/h (56 mph)
Weight59 t (58 long tons; 65 short tons)
Electric system(s)750 V DC third rail
Current collector(s)Contact shoe
UIC classificationBo'Bo'+2'2'
Safety system(s)mechanical train stop
Track gauge1,435 mm (4 ft 8+12 in) standard gauge

These trains were deployed when the section between Potsdamer Ringbahnhof and Wannsee were electrified including the part of Zehlendorf stretch.