double cars. By 2008, short-haul trains with two double-wagons were used during downtimes or on the U2 line. Technically, the cars are very similar to the Munich and Nuremberg subway trains. However, there are significant differences in the award-winning car design. By 1982, a total of 135 double railcars Type U were delivered, but are now retired. From 1987 SGP supplied with the type U1 (later referred to as U11), a second generation, which looks like its predecessor outwardly. The technical equipment has been further developed and includes water-cooled three-phase motors, brakes with energy recovery and modernized emergency braking and safety equipment. In the years 2000 to 2010 trains of the later type series of the type U were rebuilt and equipped with new three-phase motors, which should extend their life for another 20 years. The converted trains are called Type U2. These vehicles operate on the lines U2 and U3. The interior of a car consists of eight pairs of vis-à-vis seats in the middle section, nine seats on the driverless ends and two pairs of seats opposite each other in the opposite end of the car. In 2006, the U1 and U2 LED displays replaced the original in-and-out illuminated telltale displays. In addition, the trains will gradually be retrofitted with plastic seats, video surveillance and warning lights to signal the door closing operation. At Type U, no such conversions are made because the vehicles are successively scanned. An individual railcar has 49 seats and 91 standing places. In a train consisting of three double railcars, this is 294 seats and 546 standing places. The maximum speed is . The design of the "Silver Arrows" trimmings comes from the railway designer Johann Benda. V-Cars: Newer Generation In the late 1990s, a consortium of companies Siemens, ELIN and Adtranz developed a new train called Type V or "V-Car". It is a continuous, permanently coupled six-car train consisting of two non-motorized control cars and four motorized intermediate cars. This corresponds to the length of three double wagons of the Ux type family. After a prototype had been mostly used on the line U3 from December 2000, 25 sets were purchased in June 2002 and again 15 trains of this type in December 2007. Of these, the first sets were delivered from February 2005, which received their operating license in mid-August 2006 after several delays. At the end of September 2009, another