The SL C20 is a type of subway train used in the Stockholm Metro, Sweden. Between 1997 and 2004, 271 cars were delivered to Stockholm by the former Kalmar Verkstad, owned by Adtranz, later acquired by Bombardier Transportation. The C20 is a completely new design and therefore is not compatible with other train types in the system. At, each carriage is longer than the previous train types. To save cost and weight, each unit has only four bogies. The middle car has two bogies. The end parts consist of one bogie each and are connected to the central portion via a semi-trailer-direction. Trolley subframes are made of stainless steel, and are less susceptible to corrosion. When the C20 was sold as the Vagn 2000, it was marketed as the subway car of the future. All C20 coaches have been given their own names, all proposed by private individuals. Many of the names are linked to Stockholm; for example, coach no. 2001 was christened Birger Jarl.
C20F
The C20F is a related prototype, built with "FICAS" technology – a highly innovative modular construction that uses a stainless steel skin bonded to a rigid composite core. This construction results in an extremely thin wall, thereby creating a more spacious interior without altering the outer profile. The C20F has air conditioning in both the driver's cab and the passenger compartments, whereas the C20 has air conditioning in the driver's cab only. The exterior of the C20F differs by having smooth trolley sub-frames instead of the corrugated trolley sub-frames present in the C20. The C20F car assigned the carriage no. 2000 and originally christened Incognito. On 22 May 2012, the C20 carriage no. 2012, previously named Elvira, was renamed the Estelle on the occasion of Princess Estelle's baptism. The C20F was then renamed Elvira, and currently no car is named Incognito. The C20F operates on the Green Line of the Stockholm metro.
Refurbishment
The 271 cars of the C20 and C20F will undergo a mid-life refurbishment at the Bombardier Transportation factory in Västerås between 2019 and 2023. The refurbishment will increase the standing capacity of all cars by converting one side of each car to all-longitudinal seating instead of the all-transverse seating currently in use, as well as removing a portion of seats in each end of a carriage to create spaces for wheelchairs and strollers. All seat upholstery will also be replaced and new yellow upholstery to designate priority seating will also be introduced, and each refurbished C20/C20F car will be retrofitted with 16CCTV cameras, an increase of 6 such cameras in each car prior to refurbishment.
