Berlin U-Bahn rolling stock
The rolling stock on the Berlin U-Bahn are the main types of cars for the underground railway (subway).
Both networks have 1,435 mm (4 ft 8+1⁄2 in) standard gauge track and are electrified at 750 volts DC.
However, on the Nord-Süd-Bahn in the years between 1923 and 1927 and on the E line (today's U5) between 1961 and 1978, Kleinprofil trains with specially adapted power pickups ran on Grossprofil tracks.
They were fitted with special wooden boards on the sides to close the gap between platform and train.
Two test vehicles were ordered for the first Berlin U-Bahn line from the Cologne coach builders, van der Zypen & Charlier.
One of these vehicles was used by Wilhelm II in 1908, leading to their nickname Kaiserwagen ("emperor's coach").
The first production vehicles, which were appropriately titled A-I, were built in the Warschauer Brücke workshop.
At the U-Bahn's opening in 1902, 42 multiple units and 21 pure railroad cars were ready for service.
Unlike the test vehicles, the seating was placed along the walls of the train, which was considered more comfortable.
Between 1906 and 1913, a fifth batch of vehicles was delivered; these had an improved steering system, making possible 8-car trains, which had become necessary due to rising traffic.
Finally, in 1975 the Thälmannplatz — Pankow route got four prototypes of the new GI double multiple unit, called Gustav in popular parlance.
After intensive testing the LEW Hennigsdorf factory began manufacturing the trains.
The production models had lower side windows and a changed front, but were technically the same.
In 1988 a new batch of GI-trains was delivered, but with technical changes that made coupling them with the older cars impossible.
A speciality of these cars was the fact that they had only two doors per side, unlike the other Kleinprofil trains, which had three.
All the older G stock were sold to Pyongyang (GI), the G cars went for scrap, and all the GI/1 trains were refurbished into GI/1E from 2005 to 2007 in order to extend the lifespan.
In allusion to the Großprofil series H two prototypes were built in 2000, which had the designation HK - originally, the plan had been to call them A4.
Unlike their Großprofil model, cars on these trains are not fully inter-connected for passengers.
When the city of Berlin planned the new Nord-Süd-Bahn, it ordered two cars in the Großprofil with a much greater width of 2.65 metres (8 ft 8+3⁄8 in) from the Linke-Hoffmann factory in Breslau.
For the U-Bahn of the AEG company, today's U8, two prototypes were ordered from the Cologne train factory van der Zypen & Charlier.
Because they had big elliptical front windows, they were commonly called Tunneleulen ("tunnel owls").
They were 18 meters long and were tested thoroughly, before production started with the CII and CIII types.
Especially these CIV cars, but also some CII and CIII trains were seized by the Soviet occupation forces in 1945, which were stationed in the Friedrichsfelde workshop at that time.
A train with completely joined compartments was chosen, and the seats along the car walls returned.
